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-rw-r--r--arch/i386/kernel/tsc.c4
-rw-r--r--arch/x86_64/kernel/tsc.c2
-rw-r--r--drivers/lguest/core.c462
-rw-r--r--drivers/lguest/hypercalls.c192
-rw-r--r--drivers/lguest/interrupts_and_traps.c268
-rw-r--r--drivers/lguest/io.c399
-rw-r--r--drivers/lguest/lg.h261
-rw-r--r--drivers/lguest/lguest.c125
-rw-r--r--drivers/lguest/lguest_asm.S5
-rw-r--r--drivers/lguest/lguest_user.c236
-rw-r--r--drivers/lguest/page_tables.c411
-rw-r--r--drivers/lguest/segments.c125
-rw-r--r--drivers/lguest/switcher.S159
-rw-r--r--include/asm-i386/tsc.h1
-rw-r--r--include/linux/lguest.h12
-rw-r--r--include/linux/lguest_launcher.h73
-rw-r--r--kernel/fork.c1
17 files changed, 2702 insertions, 34 deletions
diff --git a/arch/i386/kernel/tsc.c b/arch/i386/kernel/tsc.c
index 252f9010f28..debd7dbb415 100644
--- a/arch/i386/kernel/tsc.c
+++ b/arch/i386/kernel/tsc.c
@@ -27,6 +27,7 @@ static int tsc_enabled;
* an extra value to store the TSC freq
*/
unsigned int tsc_khz;
+EXPORT_SYMBOL_GPL(tsc_khz);
int tsc_disable;
@@ -58,10 +59,11 @@ __setup("notsc", tsc_setup);
*/
static int tsc_unstable;
-static inline int check_tsc_unstable(void)
+int check_tsc_unstable(void)
{
return tsc_unstable;
}
+EXPORT_SYMBOL_GPL(check_tsc_unstable);
/* Accellerators for sched_clock()
* convert from cycles(64bits) => nanoseconds (64bits)
diff --git a/arch/x86_64/kernel/tsc.c b/arch/x86_64/kernel/tsc.c
index 48f9a8e6aa9..e850aa01e1b 100644
--- a/arch/x86_64/kernel/tsc.c
+++ b/arch/x86_64/kernel/tsc.c
@@ -44,7 +44,7 @@ unsigned long long sched_clock(void)
static int tsc_unstable;
-static inline int check_tsc_unstable(void)
+inline int check_tsc_unstable(void)
{
return tsc_unstable;
}
diff --git a/drivers/lguest/core.c b/drivers/lguest/core.c
new file mode 100644
index 00000000000..ce909ec5749
--- /dev/null
+++ b/drivers/lguest/core.c
@@ -0,0 +1,462 @@
+/* World's simplest hypervisor, to test paravirt_ops and show
+ * unbelievers that virtualization is the future. Plus, it's fun! */
+#include <linux/module.h>
+#include <linux/stringify.h>
+#include <linux/stddef.h>
+#include <linux/io.h>
+#include <linux/mm.h>
+#include <linux/vmalloc.h>
+#include <linux/cpu.h>
+#include <linux/freezer.h>
+#include <asm/paravirt.h>
+#include <asm/desc.h>
+#include <asm/pgtable.h>
+#include <asm/uaccess.h>
+#include <asm/poll.h>
+#include <asm/highmem.h>
+#include <asm/asm-offsets.h>
+#include <asm/i387.h>
+#include "lg.h"
+
+/* Found in switcher.S */
+extern char start_switcher_text[], end_switcher_text[], switch_to_guest[];
+extern unsigned long default_idt_entries[];
+
+/* Every guest maps the core switcher code. */
+#define SHARED_SWITCHER_PAGES \
+ DIV_ROUND_UP(end_switcher_text - start_switcher_text, PAGE_SIZE)
+/* Pages for switcher itself, then two pages per cpu */
+#define TOTAL_SWITCHER_PAGES (SHARED_SWITCHER_PAGES + 2 * NR_CPUS)
+
+/* We map at -4M for ease of mapping into the guest (one PTE page). */
+#define SWITCHER_ADDR 0xFFC00000
+
+static struct vm_struct *switcher_vma;
+static struct page **switcher_page;
+
+static int cpu_had_pge;
+static struct {
+ unsigned long offset;
+ unsigned short segment;
+} lguest_entry;
+
+/* This One Big lock protects all inter-guest data structures. */
+DEFINE_MUTEX(lguest_lock);
+static DEFINE_PER_CPU(struct lguest *, last_guest);
+
+/* FIXME: Make dynamic. */
+#define MAX_LGUEST_GUESTS 16
+struct lguest lguests[MAX_LGUEST_GUESTS];
+
+/* Offset from where switcher.S was compiled to where we've copied it */
+static unsigned long switcher_offset(void)
+{
+ return SWITCHER_ADDR - (unsigned long)start_switcher_text;
+}
+
+/* This cpu's struct lguest_pages. */
+static struct lguest_pages *lguest_pages(unsigned int cpu)
+{
+ return &(((struct lguest_pages *)
+ (SWITCHER_ADDR + SHARED_SWITCHER_PAGES*PAGE_SIZE))[cpu]);
+}
+
+static __init int map_switcher(void)
+{
+ int i, err;
+ struct page **pagep;
+
+ switcher_page = kmalloc(sizeof(switcher_page[0])*TOTAL_SWITCHER_PAGES,
+ GFP_KERNEL);
+ if (!switcher_page) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ for (i = 0; i < TOTAL_SWITCHER_PAGES; i++) {
+ unsigned long addr = get_zeroed_page(GFP_KERNEL);
+ if (!addr) {
+ err = -ENOMEM;
+ goto free_some_pages;
+ }
+ switcher_page[i] = virt_to_page(addr);
+ }
+
+ switcher_vma = __get_vm_area(TOTAL_SWITCHER_PAGES * PAGE_SIZE,
+ VM_ALLOC, SWITCHER_ADDR, VMALLOC_END);
+ if (!switcher_vma) {
+ err = -ENOMEM;
+ printk("lguest: could not map switcher pages high\n");
+ goto free_pages;
+ }
+
+ pagep = switcher_page;
+ err = map_vm_area(switcher_vma, PAGE_KERNEL, &pagep);
+ if (err) {
+ printk("lguest: map_vm_area failed: %i\n", err);
+ goto free_vma;
+ }
+ memcpy(switcher_vma->addr, start_switcher_text,
+ end_switcher_text - start_switcher_text);
+
+ /* Fix up IDT entries to point into copied text. */
+ for (i = 0; i < IDT_ENTRIES; i++)
+ default_idt_entries[i] += switcher_offset();
+
+ for_each_possible_cpu(i) {
+ struct lguest_pages *pages = lguest_pages(i);
+ struct lguest_ro_state *state = &pages->state;
+
+ /* These fields are static: rest done in copy_in_guest_info */
+ state->host_gdt_desc.size = GDT_SIZE-1;
+ state->host_gdt_desc.address = (long)get_cpu_gdt_table(i);
+ store_idt(&state->host_idt_desc);
+ state->guest_idt_desc.size = sizeof(state->guest_idt)-1;
+ state->guest_idt_desc.address = (long)&state->guest_idt;
+ state->guest_gdt_desc.size = sizeof(state->guest_gdt)-1;
+ state->guest_gdt_desc.address = (long)&state->guest_gdt;
+ state->guest_tss.esp0 = (long)(&pages->regs + 1);
+ state->guest_tss.ss0 = LGUEST_DS;
+ /* No I/O for you! */
+ state->guest_tss.io_bitmap_base = sizeof(state->guest_tss);
+ setup_default_gdt_entries(state);
+ setup_default_idt_entries(state, default_idt_entries);
+
+ /* Setup LGUEST segments on all cpus */
+ get_cpu_gdt_table(i)[GDT_ENTRY_LGUEST_CS] = FULL_EXEC_SEGMENT;
+ get_cpu_gdt_table(i)[GDT_ENTRY_LGUEST_DS] = FULL_SEGMENT;
+ }
+
+ /* Initialize entry point into switcher. */
+ lguest_entry.offset = (long)switch_to_guest + switcher_offset();
+ lguest_entry.segment = LGUEST_CS;
+
+ printk(KERN_INFO "lguest: mapped switcher at %p\n",
+ switcher_vma->addr);
+ return 0;
+
+free_vma:
+ vunmap(switcher_vma->addr);
+free_pages:
+ i = TOTAL_SWITCHER_PAGES;
+free_some_pages:
+ for (--i; i >= 0; i--)
+ __free_pages(switcher_page[i], 0);
+ kfree(switcher_page);
+out:
+ return err;
+}
+
+static void unmap_switcher(void)
+{
+ unsigned int i;
+
+ vunmap(switcher_vma->addr);
+ for (i = 0; i < TOTAL_SWITCHER_PAGES; i++)
+ __free_pages(switcher_page[i], 0);
+}
+
+/* IN/OUT insns: enough to get us past boot-time probing. */
+static int emulate_insn(struct lguest *lg)
+{
+ u8 insn;
+ unsigned int insnlen = 0, in = 0, shift = 0;
+ unsigned long physaddr = guest_pa(lg, lg->regs->eip);
+
+ /* This only works for addresses in linear mapping... */
+ if (lg->regs->eip < lg->page_offset)
+ return 0;
+ lgread(lg, &insn, physaddr, 1);
+
+ /* Operand size prefix means it's actually for ax. */
+ if (insn == 0x66) {
+ shift = 16;
+ insnlen = 1;
+ lgread(lg, &insn, physaddr + insnlen, 1);
+ }
+
+ switch (insn & 0xFE) {
+ case 0xE4: /* in <next byte>,%al */
+ insnlen += 2;
+ in = 1;
+ break;
+ case 0xEC: /* in (%dx),%al */
+ insnlen += 1;
+ in = 1;
+ break;
+ case 0xE6: /* out %al,<next byte> */
+ insnlen += 2;
+ break;
+ case 0xEE: /* out %al,(%dx) */
+ insnlen += 1;
+ break;
+ default:
+ return 0;
+ }
+
+ if (in) {
+ /* Lower bit tells is whether it's a 16 or 32 bit access */
+ if (insn & 0x1)
+ lg->regs->eax = 0xFFFFFFFF;
+ else
+ lg->regs->eax |= (0xFFFF << shift);
+ }
+ lg->regs->eip += insnlen;
+ return 1;
+}
+
+int lguest_address_ok(const struct lguest *lg,
+ unsigned long addr, unsigned long len)
+{
+ return (addr+len) / PAGE_SIZE < lg->pfn_limit && (addr+len >= addr);
+}
+
+/* Just like get_user, but don't let guest access lguest binary. */
+u32 lgread_u32(struct lguest *lg, unsigned long addr)
+{
+ u32 val = 0;
+
+ /* Don't let them access lguest binary */
+ if (!lguest_address_ok(lg, addr, sizeof(val))
+ || get_user(val, (u32 __user *)addr) != 0)
+ kill_guest(lg, "bad read address %#lx", addr);
+ return val;
+}
+
+void lgwrite_u32(struct lguest *lg, unsigned long addr, u32 val)
+{
+ if (!lguest_address_ok(lg, addr, sizeof(val))
+ || put_user(val, (u32 __user *)addr) != 0)
+ kill_guest(lg, "bad write address %#lx", addr);
+}
+
+void lgread(struct lguest *lg, void *b, unsigned long addr, unsigned bytes)
+{
+ if (!lguest_address_ok(lg, addr, bytes)
+ || copy_from_user(b, (void __user *)addr, bytes) != 0) {
+ /* copy_from_user should do this, but as we rely on it... */
+ memset(b, 0, bytes);
+ kill_guest(lg, "bad read address %#lx len %u", addr, bytes);
+ }
+}
+
+void lgwrite(struct lguest *lg, unsigned long addr, const void *b,
+ unsigned bytes)
+{
+ if (!lguest_address_ok(lg, addr, bytes)
+ || copy_to_user((void __user *)addr, b, bytes) != 0)
+ kill_guest(lg, "bad write address %#lx len %u", addr, bytes);
+}
+
+static void set_ts(void)
+{
+ u32 cr0;
+
+ cr0 = read_cr0();
+ if (!(cr0 & 8))
+ write_cr0(cr0|8);
+}
+
+static void copy_in_guest_info(struct lguest *lg, struct lguest_pages *pages)
+{
+ if (__get_cpu_var(last_guest) != lg || lg->last_pages != pages) {
+ __get_cpu_var(last_guest) = lg;
+ lg->last_pages = pages;
+ lg->changed = CHANGED_ALL;
+ }
+
+ /* These are pretty cheap, so we do them unconditionally. */
+ pages->state.host_cr3 = __pa(current->mm->pgd);
+ map_switcher_in_guest(lg, pages);
+ pages->state.guest_tss.esp1 = lg->esp1;
+ pages->state.guest_tss.ss1 = lg->ss1;
+
+ /* Copy direct trap entries. */
+ if (lg->changed & CHANGED_IDT)
+ copy_traps(lg, pages->state.guest_idt, default_idt_entries);
+
+ /* Copy all GDT entries but the TSS. */
+ if (lg->changed & CHANGED_GDT)
+ copy_gdt(lg, pages->state.guest_gdt);
+ /* If only the TLS entries have changed, copy them. */
+ else if (lg->changed & CHANGED_GDT_TLS)
+ copy_gdt_tls(lg, pages->state.guest_gdt);
+
+ lg->changed = 0;
+}
+
+static void run_guest_once(struct lguest *lg, struct lguest_pages *pages)
+{
+ unsigned int clobber;
+
+ copy_in_guest_info(lg, pages);
+
+ /* Put eflags on stack, lcall does rest: suitable for iret return. */
+ asm volatile("pushf; lcall *lguest_entry"
+ : "=a"(clobber), "=b"(clobber)
+ : "0"(pages), "1"(__pa(lg->pgdirs[lg->pgdidx].pgdir))
+ : "memory", "%edx", "%ecx", "%edi", "%esi");
+}
+
+int run_guest(struct lguest *lg, unsigned long __user *user)
+{
+ while (!lg->dead) {
+ unsigned int cr2 = 0; /* Damn gcc */
+
+ /* Hypercalls first: we might have been out to userspace */
+ do_hypercalls(lg);
+ if (lg->dma_is_pending) {
+ if (put_user(lg->pending_dma, user) ||
+ put_user(lg->pending_key, user+1))
+ return -EFAULT;
+ return sizeof(unsigned long)*2;
+ }
+
+ if (signal_pending(current))
+ return -ERESTARTSYS;
+
+ /* If Waker set break_out, return to Launcher. */
+ if (lg->break_out)
+ return -EAGAIN;
+
+ maybe_do_interrupt(lg);
+
+ try_to_freeze();
+
+ if (lg->dead)
+ break;
+
+ if (lg->halted) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule();
+ continue;
+ }
+
+ local_irq_disable();
+
+ /* Even if *we* don't want FPU trap, guest might... */
+ if (lg->ts)
+ set_ts();
+
+ /* Don't let Guest do SYSENTER: we can't handle it. */
+ if (boot_cpu_has(X86_FEATURE_SEP))
+ wrmsr(MSR_IA32_SYSENTER_CS, 0, 0);
+
+ run_guest_once(lg, lguest_pages(raw_smp_processor_id()));
+
+ /* Save cr2 now if we page-faulted. */
+ if (lg->regs->trapnum == 14)
+ cr2 = read_cr2();
+ else if (lg->regs->trapnum == 7)
+ math_state_restore();
+
+ if (boot_cpu_has(X86_FEATURE_SEP))
+ wrmsr(MSR_IA32_SYSENTER_CS, __KERNEL_CS, 0);
+ local_irq_enable();
+
+ switch (lg->regs->trapnum) {
+ case 13: /* We've intercepted a GPF. */
+ if (lg->regs->errcode == 0) {
+ if (emulate_insn(lg))
+ continue;
+ }
+ break;
+ case 14: /* We've intercepted a page fault. */
+ if (demand_page(lg, cr2, lg->regs->errcode))
+ continue;
+
+ /* If lguest_data is NULL, this won't hurt. */
+ if (put_user(cr2, &lg->lguest_data->cr2))
+ kill_guest(lg, "Writing cr2");
+ break;
+ case 7: /* We've intercepted a Device Not Available fault. */
+ /* If they don't want to know, just absorb it. */
+ if (!lg->ts)
+ continue;
+ break;
+ case 32 ... 255: /* Real interrupt, fall thru */
+ cond_resched();
+ case LGUEST_TRAP_ENTRY: /* Handled at top of loop */
+ continue;
+ }
+
+ if (deliver_trap(lg, lg->regs->trapnum))
+ continue;
+
+ kill_guest(lg, "unhandled trap %li at %#lx (%#lx)",
+ lg->regs->trapnum, lg->regs->eip,
+ lg->regs->trapnum == 14 ? cr2 : lg->regs->errcode);
+ }
+ return -ENOENT;
+}
+
+int find_free_guest(void)
+{
+ unsigned int i;
+ for (i = 0; i < MAX_LGUEST_GUESTS; i++)
+ if (!lguests[i].tsk)
+ return i;
+ return -1;
+}
+
+static void adjust_pge(void *on)
+{
+ if (on)
+ write_cr4(read_cr4() | X86_CR4_PGE);
+ else
+ write_cr4(read_cr4() & ~X86_CR4_PGE);
+}
+
+static int __init init(void)
+{
+ int err;
+
+ if (paravirt_enabled()) {
+ printk("lguest is afraid of %s\n", paravirt_ops.name);
+ return -EPERM;
+ }
+
+ err = map_switcher();
+ if (err)
+ return err;
+
+ err = init_pagetables(switcher_page, SHARED_SWITCHER_PAGES);
+ if (err) {
+ unmap_switcher();
+ return err;
+ }
+ lguest_io_init();
+
+ err = lguest_device_init();
+ if (err) {
+ free_pagetables();
+ unmap_switcher();
+ return err;
+ }
+ lock_cpu_hotplug();
+ if (cpu_has_pge) { /* We have a broader idea of "global". */
+ cpu_had_pge = 1;
+ on_each_cpu(adjust_pge, (void *)0, 0, 1);
+ clear_bit(X86_FEATURE_PGE, boot_cpu_data.x86_capability);
+ }
+ unlock_cpu_hotplug();
+ return 0;
+}
+
+static void __exit fini(void)
+{
+ lguest_device_remove();
+ free_pagetables();
+ unmap_switcher();
+ lock_cpu_hotplug();
+ if (cpu_had_pge) {
+ set_bit(X86_FEATURE_PGE, boot_cpu_data.x86_capability);
+ on_each_cpu(adjust_pge, (void *)1, 0, 1);
+ }
+ unlock_cpu_hotplug();
+}
+
+module_init(init);
+module_exit(fini);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Rusty Russell <rusty@rustcorp.com.au>");
diff --git a/drivers/lguest/hypercalls.c b/drivers/lguest/hypercalls.c
new file mode 100644
index 00000000000..ea52ca451f7
--- /dev/null
+++ b/drivers/lguest/hypercalls.c
@@ -0,0 +1,192 @@
+/* Actual hypercalls, which allow guests to actually do something.
+ Copyright (C) 2006 Rusty Russell IBM Corporation
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+*/
+#include <linux/uaccess.h>
+#include <linux/syscalls.h>
+#include <linux/mm.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <irq_vectors.h>
+#include "lg.h"
+
+static void do_hcall(struct lguest *lg, struct lguest_regs *regs)
+{
+ switch (regs->eax) {
+ case LHCALL_FLUSH_ASYNC:
+ break;
+ case LHCALL_LGUEST_INIT:
+ kill_guest(lg, "already have lguest_data");
+ break;
+ case LHCALL_CRASH: {
+ char msg[128];
+ lgread(lg, msg, regs->edx, sizeof(msg));
+ msg[sizeof(msg)-1] = '\0';
+ kill_guest(lg, "CRASH: %s", msg);
+ break;
+ }
+ case LHCALL_FLUSH_TLB:
+ if (regs->edx)
+ guest_pagetable_clear_all(lg);
+ else
+ guest_pagetable_flush_user(lg);
+ break;
+ case LHCALL_GET_WALLCLOCK: {
+ struct timespec ts;
+ ktime_get_real_ts(&ts);
+ regs->eax = ts.tv_sec;
+ break;
+ }
+ case LHCALL_BIND_DMA:
+ regs->eax = bind_dma(lg, regs->edx, regs->ebx,
+ regs->ecx >> 8, regs->ecx & 0xFF);
+ break;
+ case LHCALL_SEND_DMA:
+ send_dma(lg, regs->edx, regs->ebx);
+ break;
+ case LHCALL_LOAD_GDT:
+ load_guest_gdt(lg, regs->edx, regs->ebx);
+ break;
+ case LHCALL_LOAD_IDT_ENTRY:
+ load_guest_idt_entry(lg, regs->edx, regs->ebx, regs->ecx);
+ break;
+ case LHCALL_NEW_PGTABLE:
+ guest_new_pagetable(lg, regs->edx);
+ break;
+ case LHCALL_SET_STACK:
+ guest_set_stack(lg, regs->edx, regs->ebx, regs->ecx);
+ break;
+ case LHCALL_SET_PTE:
+ guest_set_pte(lg, regs->edx, regs->ebx, mkgpte(regs->ecx));
+ break;
+ case LHCALL_SET_PMD:
+ guest_set_pmd(lg, regs->edx, regs->ebx);
+ break;
+ case LHCALL_LOAD_TLS:
+ guest_load_tls(lg, regs->edx);
+ break;
+ case LHCALL_SET_CLOCKEVENT:
+ guest_set_clockevent(lg, regs->edx);
+ break;
+ case LHCALL_TS:
+ lg->ts = regs->edx;
+ break;
+ case LHCALL_HALT:
+ lg->halted = 1;
+ break;
+ default:
+ kill_guest(lg, "Bad hypercall %li\n", regs->eax);
+ }
+}
+
+/* We always do queued calls before actual hypercall. */
+static void do_async_hcalls(struct lguest *lg)
+{
+ unsigned int i;
+ u8 st[LHCALL_RING_SIZE];
+
+ if (copy_from_user(&st, &lg->lguest_data->hcall_status, sizeof(st)))
+ return;
+
+ for (i = 0; i < ARRAY_SIZE(st); i++) {
+ struct lguest_regs regs;
+ unsigned int n = lg->next_hcall;
+
+ if (st[n] == 0xFF)
+ break;
+
+ if (++lg->next_hcall == LHCALL_RING_SIZE)
+ lg->next_hcall = 0;
+
+ if (get_user(regs.eax, &lg->lguest_data->hcalls[n].eax)
+ || get_user(regs.edx, &lg->lguest_data->hcalls[n].edx)
+ || get_user(regs.ecx, &lg->lguest_data->hcalls[n].ecx)
+ || get_user(regs.ebx, &lg->lguest_data->hcalls[n].ebx)) {
+ kill_guest(lg, "Fetching async hypercalls");
+ break;
+ }
+
+ do_hcall(lg, &regs);
+ if (put_user(0xFF, &lg->lguest_data->hcall_status[n])) {
+ kill_guest(lg, "Writing result for async hypercall");
+ break;
+ }
+
+ if (lg->dma_is_pending)
+ break;
+ }
+}
+
+static void initialize(struct lguest *lg)
+{
+ u32 tsc_speed;
+
+ if (lg->regs->eax != LHCALL_LGUEST_INIT) {
+ kill_guest(lg, "hypercall %li before LGUEST_INIT",
+ lg->regs->eax);
+ return;
+ }
+
+ /* We only tell the guest to use the TSC if it's reliable. */
+ if (boot_cpu_has(X86_FEATURE_CONSTANT_TSC) && !check_tsc_unstable())
+ tsc_speed = tsc_khz;
+ else
+ tsc_speed = 0;
+
+ lg->lguest_data = (struct lguest_data __user *)lg->regs->edx;
+ /* We check here so we can simply copy_to_user/from_user */
+ if (!lguest_address_ok(lg, lg->regs->edx, sizeof(*lg->lguest_data))) {
+ kill_guest(lg, "bad guest page %p", lg->lguest_data);
+ return;
+ }
+ if (get_user(lg->noirq_start, &lg->lguest_data->noirq_start)
+ || get_user(lg->noirq_end, &lg->lguest_data->noirq_end)
+ /* We reserve the top pgd entry. */
+ || put_user(4U*1024*1024, &lg->lguest_data->reserve_mem)
+ || put_user(tsc_speed, &lg->lguest_data->tsc_khz)
+ || put_user(lg->guestid, &lg->lguest_data->guestid))
+ kill_guest(lg, "bad guest page %p", lg->lguest_data);
+
+ /* This is the one case where the above accesses might have
+ * been the first write to a Guest page. This may have caused
+ * a copy-on-write fault, but the Guest might be referring to
+ * the old (read-only) page. */
+ guest_pagetable_clear_all(lg);
+}
+
+/* Even if we go out to userspace and come back, we don't want to do
+ * the hypercall again. */
+static void clear_hcall(struct lguest *lg)
+{
+ lg->regs->trapnum = 255;
+}
+
+void do_hypercalls(struct lguest *lg)
+{
+ if (unlikely(!lg->lguest_data)) {
+ if (lg->regs->trapnum == LGUEST_TRAP_ENTRY) {
+ initialize(lg);
+ clear_hcall(lg);
+ }
+ return;
+ }
+
+ do_async_hcalls(lg);
+ if (!lg->dma_is_pending && lg->regs->trapnum == LGUEST_TRAP_ENTRY) {
+ do_hcall(lg, lg->regs);
+ clear_hcall(lg);
+ }
+}
diff --git a/drivers/lguest/interrupts_and_traps.c b/drivers/lguest/interrupts_and_traps.c
new file mode 100644
index 00000000000..d9de5bbc613
--- /dev/null
+++ b/drivers/lguest/interrupts_and_traps.c
@@ -0,0 +1,268 @@
+#include <linux/uaccess.h>
+#include "lg.h"
+
+static unsigned long idt_address(u32 lo, u32 hi)
+{
+ return (lo & 0x0000FFFF) | (hi & 0xFFFF0000);
+}
+
+static int idt_type(u32 lo, u32 hi)
+{
+ return (hi >> 8) & 0xF;
+}
+
+static int idt_present(u32 lo, u32 hi)
+{
+ return (hi & 0x8000);
+}
+
+static void push_guest_stack(struct lguest *lg, unsigned long *gstack, u32 val)
+{
+ *gstack -= 4;
+ lgwrite_u32(lg, *gstack, val);
+}
+
+static void set_guest_interrupt(struct lguest *lg, u32 lo, u32 hi, int has_err)
+{
+ unsigned long gstack;
+ u32 eflags, ss, irq_enable;
+
+ /* If they want a ring change, we use new stack and push old ss/esp */
+ if ((lg->regs->ss&0x3) != GUEST_PL) {
+ gstack = guest_pa(lg, lg->esp1);
+ ss = lg->ss1;
+ push_guest_stack(lg, &gstack, lg->regs->ss);
+ push_guest_stack(lg, &gstack, lg->regs->esp);
+ } else {
+ gstack = guest_pa(lg, lg->regs->esp);
+ ss = lg->regs->ss;
+ }
+
+ /* We use IF bit in eflags to indicate whether irqs were disabled
+ (it's always 0, since irqs are enabled when guest is running). */
+ eflags = lg->regs->eflags;
+ if (get_user(irq_enable, &lg->lguest_data->irq_enabled))
+ irq_enable = 0;
+ eflags |= (irq_enable & X86_EFLAGS_IF);
+
+ push_guest_stack(lg, &gstack, eflags);
+ push_guest_stack(lg, &gstack, lg->regs->cs);
+ push_guest_stack(lg, &gstack, lg->regs->eip);
+
+ if (has_err)
+ push_guest_stack(lg, &gstack, lg->regs->errcode);
+
+ /* Change the real stack so switcher returns to trap handler */
+ lg->regs->ss = ss;
+ lg->regs->esp = gstack + lg->page_offset;
+ lg->regs->cs = (__KERNEL_CS|GUEST_PL);
+ lg->regs->eip = idt_address(lo, hi);
+
+ /* Disable interrupts for an interrupt gate. */
+ if (idt_type(lo, hi) == 0xE)
+ if (put_user(0, &lg->lguest_data->irq_enabled))
+ kill_guest(lg, "Disabling interrupts");
+}
+
+void maybe_do_interrupt(struct lguest *lg)
+{
+ unsigned int irq;
+ DECLARE_BITMAP(blk, LGUEST_IRQS);
+ struct desc_struct *idt;
+
+ if (!lg->lguest_data)
+ return;
+
+ /* Mask out any interrupts they have blocked. */
+ if (copy_from_user(&blk, lg->lguest_data->blocked_interrupts,
+ sizeof(blk)))
+ return;
+
+ bitmap_andnot(blk, lg->irqs_pending, blk, LGUEST_IRQS);
+
+ irq = find_first_bit(blk, LGUEST_IRQS);
+ if (irq >= LGUEST_IRQS)
+ return;
+
+ if (lg->regs->eip >= lg->noirq_start && lg->regs->eip < lg->noirq_end)
+ return;
+
+ /* If they're halted, we re-enable interrupts. */
+ if (lg->halted) {
+ /* Re-enable interrupts. */
+ if (put_user(X86_EFLAGS_IF, &lg->lguest_data->irq_enabled))
+ kill_guest(lg, "Re-enabling interrupts");
+ lg->halted = 0;
+ } else {
+ /* Maybe they have interrupts disabled? */
+ u32 irq_enabled;
+ if (get_user(irq_enabled, &lg->lguest_data->irq_enabled))
+ irq_enabled = 0;
+ if (!irq_enabled)
+ return;
+ }
+
+ idt = &lg->idt[FIRST_EXTERNAL_VECTOR+irq];
+ if (idt_present(idt->a, idt->b)) {
+ clear_bit(irq, lg->irqs_pending);
+ set_guest_interrupt(lg, idt->a, idt->b, 0);
+ }
+}
+
+static int has_err(unsigned int trap)
+{
+ return (trap == 8 || (trap >= 10 && trap <= 14) || trap == 17);
+}
+
+int deliver_trap(struct lguest *lg, unsigned int num)
+{
+ u32 lo = lg->idt[num].a, hi = lg->idt[num].b;
+
+ if (!idt_present(lo, hi))
+ return 0;
+ set_guest_interrupt(lg, lo, hi, has_err(num));
+ return 1;
+}
+
+static int direct_trap(const struct lguest *lg,
+ const struct desc_struct *trap,
+ unsigned int num)
+{
+ /* Hardware interrupts don't go to guest (except syscall). */
+ if (num >= FIRST_EXTERNAL_VECTOR && num != SYSCALL_VECTOR)
+ return 0;
+
+ /* We intercept page fault (demand shadow paging & cr2 saving)
+ protection fault (in/out emulation) and device not
+ available (TS handling), and hypercall */
+ if (num == 14 || num == 13 || num == 7 || num == LGUEST_TRAP_ENTRY)
+ return 0;
+
+ /* Interrupt gates (0xE) or not present (0x0) can't go direct. */
+ return idt_type(trap->a, trap->b) == 0xF;
+}
+
+void pin_stack_pages(struct lguest *lg)
+{
+ unsigned int i;
+
+ for (i = 0; i < lg->stack_pages; i++)
+ pin_page(lg, lg->esp1 - i * PAGE_SIZE);
+}
+
+void guest_set_stack(struct lguest *lg, u32 seg, u32 esp, unsigned int pages)
+{
+ /* You cannot have a stack segment with priv level 0. */
+ if ((seg & 0x3) != GUEST_PL)
+ kill_guest(lg, "bad stack segment %i", seg);
+ if (pages > 2)
+ kill_guest(lg, "bad stack pages %u", pages);
+ lg->ss1 = seg;
+ lg->esp1 = esp;
+ lg->stack_pages = pages;
+ pin_stack_pages(lg);
+}
+
+/* Set up trap in IDT. */
+static void set_trap(struct lguest *lg, struct desc_struct *trap,
+ unsigned int num, u32 lo, u32 hi)
+{
+ u8 type = idt_type(lo, hi);
+
+ if (!idt_present(lo, hi)) {
+ trap->a = trap->b = 0;
+ return;
+ }
+
+ if (type != 0xE && type != 0xF)
+ kill_guest(lg, "bad IDT type %i", type);
+
+ trap->a = ((__KERNEL_CS|GUEST_PL)<<16) | (lo&0x0000FFFF);
+ trap->b = (hi&0xFFFFEF00);
+}
+
+void load_guest_idt_entry(struct lguest *lg, unsigned int num, u32 lo, u32 hi)
+{
+ /* Guest never handles: NMI, doublefault, hypercall, spurious irq. */
+ if (num == 2 || num == 8 || num == 15 || num == LGUEST_TRAP_ENTRY)
+ return;
+
+ lg->changed |= CHANGED_IDT;
+ if (num < ARRAY_SIZE(lg->idt))
+ set_trap(lg, &lg->idt[num], num, lo, hi);
+ else if (num == SYSCALL_VECTOR)
+ set_trap(lg, &lg->syscall_idt, num, lo, hi);
+}
+
+static void default_idt_entry(struct desc_struct *idt,
+ int trap,
+ const unsigned long handler)
+{
+ u32 flags = 0x8e00;
+
+ /* They can't "int" into any of them except hypercall. */
+ if (trap == LGUEST_TRAP_ENTRY)
+ flags |= (GUEST_PL << 13);
+
+ idt->a = (LGUEST_CS<<16) | (handler&0x0000FFFF);
+ idt->b = (handler&0xFFFF0000) | flags;
+}
+
+void setup_default_idt_entries(struct lguest_ro_state *state,
+ const unsigned long *def)
+{
+ unsigned int i;
+
+ for (i = 0; i < ARRAY_SIZE(state->guest_idt); i++)
+ default_idt_entry(&state->guest_idt[i], i, def[i]);
+}
+
+void copy_traps(const struct lguest *lg, struct desc_struct *idt,
+ const unsigned long *def)
+{
+ unsigned int i;
+
+ /* All hardware interrupts are same whatever the guest: only the
+ * traps might be different. */
+ for (i = 0; i < FIRST_EXTERNAL_VECTOR; i++) {
+ if (direct_trap(lg, &lg->idt[i], i))
+ idt[i] = lg->idt[i];
+ else
+ default_idt_entry(&idt[i], i, def[i]);
+ }
+ i = SYSCALL_VECTOR;
+ if (direct_trap(lg, &lg->syscall_idt, i))
+ idt[i] = lg->syscall_idt;
+ else
+ default_idt_entry(&idt[i], i, def[i]);
+}
+
+void guest_set_clockevent(struct lguest *lg, unsigned long delta)
+{
+ ktime_t expires;
+
+ if (unlikely(delta == 0)) {
+ /* Clock event device is shutting down. */
+ hrtimer_cancel(&lg->hrt);
+ return;
+ }
+
+ expires = ktime_add_ns(ktime_get_real(), delta);
+ hrtimer_start(&lg->hrt, expires, HRTIMER_MODE_ABS);
+}
+
+static enum hrtimer_restart clockdev_fn(struct hrtimer *timer)
+{
+ struct lguest *lg = container_of(timer, struct lguest, hrt);
+
+ set_bit(0, lg->irqs_pending);
+ if (lg->halted)
+ wake_up_process(lg->tsk);
+ return HRTIMER_NORESTART;
+}
+
+void init_clockdev(struct lguest *lg)
+{
+ hrtimer_init(&lg->hrt, CLOCK_REALTIME, HRTIMER_MODE_ABS);
+ lg->hrt.function = clockdev_fn;
+}
diff --git a/drivers/lguest/io.c b/drivers/lguest/io.c
new file mode 100644
index 00000000000..06bdba2337e
--- /dev/null
+++ b/drivers/lguest/io.c
@@ -0,0 +1,399 @@
+/* Simple I/O model for guests, based on shared memory.
+ * Copyright (C) 2006 Rusty Russell IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+#include <linux/types.h>
+#include <linux/futex.h>
+#include <linux/jhash.h>
+#include <linux/mm.h>
+#include <linux/highmem.h>
+#include <linux/uaccess.h>
+#include "lg.h"
+
+static struct list_head dma_hash[61];
+
+void lguest_io_init(void)
+{
+ unsigned int i;
+
+ for (i = 0; i < ARRAY_SIZE(dma_hash); i++)
+ INIT_LIST_HEAD(&dma_hash[i]);
+}
+
+/* FIXME: allow multi-page lengths. */
+static int check_dma_list(struct lguest *lg, const struct lguest_dma *dma)
+{
+ unsigned int i;
+
+ for (i = 0; i < LGUEST_MAX_DMA_SECTIONS; i++) {
+ if (!dma->len[i])
+ return 1;
+ if (!lguest_address_ok(lg, dma->addr[i], dma->len[i]))
+ goto kill;
+ if (dma->len[i] > PAGE_SIZE)
+ goto kill;
+ /* We could do over a page, but is it worth it? */
+ if ((dma->addr[i] % PAGE_SIZE) + dma->len[i] > PAGE_SIZE)
+ goto kill;
+ }
+ return 1;
+
+kill:
+ kill_guest(lg, "bad DMA entry: %u@%#lx", dma->len[i], dma->addr[i]);
+ return 0;
+}
+
+static unsigned int hash(const union futex_key *key)
+{
+ return jhash2((u32*)&key->both.word,
+ (sizeof(key->both.word)+sizeof(key->both.ptr))/4,
+ key->both.offset)
+ % ARRAY_SIZE(dma_hash);
+}
+
+static inline int key_eq(const union futex_key *a, const union futex_key *b)
+{
+ return (a->both.word == b->both.word
+ && a->both.ptr == b->both.ptr
+ && a->both.offset == b->both.offset);
+}
+
+/* Must hold read lock on dmainfo owner's current->mm->mmap_sem */
+static void unlink_dma(struct lguest_dma_info *dmainfo)
+{
+ BUG_ON(!mutex_is_locked(&lguest_lock));
+ dmainfo->interrupt = 0;
+ list_del(&dmainfo->list);
+ drop_futex_key_refs(&dmainfo->key);
+}
+
+static int unbind_dma(struct lguest *lg,
+ const union futex_key *key,
+ unsigned long dmas)
+{
+ int i, ret = 0;
+
+ for (i = 0; i < LGUEST_MAX_DMA; i++) {
+ if (key_eq(key, &lg->dma[i].key) && dmas == lg->dma[i].dmas) {
+ unlink_dma(&lg->dma[i]);
+ ret = 1;
+ break;
+ }
+ }
+ return ret;
+}
+
+int bind_dma(struct lguest *lg,
+ unsigned long ukey, unsigned long dmas, u16 numdmas, u8 interrupt)
+{
+ unsigned int i;
+ int ret = 0;
+ union futex_key key;
+ struct rw_semaphore *fshared = &current->mm->mmap_sem;
+
+ if (interrupt >= LGUEST_IRQS)
+ return 0;
+
+ mutex_lock(&lguest_lock);
+ down_read(fshared);
+ if (get_futex_key((u32 __user *)ukey, fshared, &key) != 0) {
+ kill_guest(lg, "bad dma key %#lx", ukey);
+ goto unlock;
+ }
+ get_futex_key_refs(&key);
+
+ if (interrupt == 0)
+ ret = unbind_dma(lg, &key, dmas);
+ else {
+ for (i = 0; i < LGUEST_MAX_DMA; i++) {
+ if (lg->dma[i].interrupt)
+ continue;
+
+ lg->dma[i].dmas = dmas;
+ lg->dma[i].num_dmas = numdmas;
+ lg->dma[i].next_dma = 0;
+ lg->dma[i].key = key;
+ lg->dma[i].guestid = lg->guestid;
+ lg->dma[i].interrupt = interrupt;
+ list_add(&lg->dma[i].list, &dma_hash[hash(&key)]);
+ ret = 1;
+ goto unlock;
+ }
+ }
+ drop_futex_key_refs(&key);
+unlock:
+ up_read(fshared);
+ mutex_unlock(&lguest_lock);
+ return ret;
+}
+
+/* lgread from another guest */
+static int lgread_other(struct lguest *lg,
+ void *buf, u32 addr, unsigned bytes)
+{
+ if (!lguest_address_ok(lg, addr, bytes)
+ || access_process_vm(lg->tsk, addr, buf, bytes, 0) != bytes) {
+ memset(buf, 0, bytes);
+ kill_guest(lg, "bad address in registered DMA struct");
+ return 0;
+ }
+ return 1;
+}
+
+/* lgwrite to another guest */
+static int lgwrite_other(struct lguest *lg, u32 addr,
+ const void *buf, unsigned bytes)
+{
+ if (!lguest_address_ok(lg, addr, bytes)
+ || (access_process_vm(lg->tsk, addr, (void *)buf, bytes, 1)
+ != bytes)) {
+ kill_guest(lg, "bad address writing to registered DMA");
+ return 0;
+ }
+ return 1;
+}
+
+static u32 copy_data(struct lguest *srclg,
+ const struct lguest_dma *src,
+ const struct lguest_dma *dst,
+ struct page *pages[])
+{
+ unsigned int totlen, si, di, srcoff, dstoff;
+ void *maddr = NULL;
+
+ totlen = 0;
+ si = di = 0;
+ srcoff = dstoff = 0;
+ while (si < LGUEST_MAX_DMA_SECTIONS && src->len[si]
+ && di < LGUEST_MAX_DMA_SECTIONS && dst->len[di]) {
+ u32 len = min(src->len[si] - srcoff, dst->len[di] - dstoff);
+
+ if (!maddr)
+ maddr = kmap(pages[di]);
+
+ /* FIXME: This is not completely portable, since
+ archs do different things for copy_to_user_page. */
+ if (copy_from_user(maddr + (dst->addr[di] + dstoff)%PAGE_SIZE,
+ (void *__user)src->addr[si], len) != 0) {
+ kill_guest(srclg, "bad address in sending DMA");
+ totlen = 0;
+ break;
+ }
+
+ totlen += len;
+ srcoff += len;
+ dstoff += len;
+ if (srcoff == src->len[si]) {
+ si++;
+ srcoff = 0;
+ }
+ if (dstoff == dst->len[di]) {
+ kunmap(pages[di]);
+ maddr = NULL;
+ di++;
+ dstoff = 0;
+ }
+ }
+
+ if (maddr)
+ kunmap(pages[di]);
+
+ return totlen;
+}
+
+/* Src is us, ie. current. */
+static u32 do_dma(struct lguest *srclg, const struct lguest_dma *src,
+ struct lguest *dstlg, const struct lguest_dma *dst)
+{
+ int i;
+ u32 ret;
+ struct page *pages[LGUEST_MAX_DMA_SECTIONS];
+
+ if (!check_dma_list(dstlg, dst) || !check_dma_list(srclg, src))
+ return 0;
+
+ /* First get the destination pages */
+ for (i = 0; i < LGUEST_MAX_DMA_SECTIONS; i++) {
+ if (dst->len[i] == 0)
+ break;
+ if (get_user_pages(dstlg->tsk, dstlg->mm,
+ dst->addr[i], 1, 1, 1, pages+i, NULL)
+ != 1) {
+ kill_guest(dstlg, "Error mapping DMA pages");
+ ret = 0;
+ goto drop_pages;
+ }
+ }
+
+ /* Now copy until we run out of src or dst. */
+ ret = copy_data(srclg, src, dst, pages);
+
+drop_pages:
+ while (--i >= 0)
+ put_page(pages[i]);
+ return ret;
+}
+
+static int dma_transfer(struct lguest *srclg,
+ unsigned long udma,
+ struct lguest_dma_info *dst)
+{
+ struct lguest_dma dst_dma, src_dma;
+ struct lguest *dstlg;
+ u32 i, dma = 0;
+
+ dstlg = &lguests[dst->guestid];
+ /* Get our dma list. */
+ lgread(srclg, &src_dma, udma, sizeof(src_dma));
+
+ /* We can't deadlock against them dmaing to us, because this
+ * is all under the lguest_lock. */
+ down_read(&dstlg->mm->mmap_sem);
+
+ for (i = 0; i < dst->num_dmas; i++) {
+ dma = (dst->next_dma + i) % dst->num_dmas;
+ if (!lgread_other(dstlg, &dst_dma,
+ dst->dmas + dma * sizeof(struct lguest_dma),
+ sizeof(dst_dma))) {
+ goto fail;
+ }
+ if (!dst_dma.used_len)
+ break;
+ }
+ if (i != dst->num_dmas) {
+ unsigned long used_lenp;
+ unsigned int ret;
+
+ ret = do_dma(srclg, &src_dma, dstlg, &dst_dma);
+ /* Put used length in src. */
+ lgwrite_u32(srclg,
+ udma+offsetof(struct lguest_dma, used_len), ret);
+ if (ret == 0 && src_dma.len[0] != 0)
+ goto fail;
+
+ /* Make sure destination sees contents before length. */
+ wmb();
+ used_lenp = dst->dmas
+ + dma * sizeof(struct lguest_dma)
+ + offsetof(struct lguest_dma, used_len);
+ lgwrite_other(dstlg, used_lenp, &ret, sizeof(ret));
+ dst->next_dma++;
+ }
+ up_read(&dstlg->mm->mmap_sem);
+
+ /* Do this last so dst doesn't simply sleep on lock. */
+ set_bit(dst->interrupt, dstlg->irqs_pending);
+ wake_up_process(dstlg->tsk);
+ return i == dst->num_dmas;
+
+fail:
+ up_read(&dstlg->mm->mmap_sem);
+ return 0;
+}
+
+void send_dma(struct lguest *lg, unsigned long ukey, unsigned long udma)
+{
+ union futex_key key;
+ int empty = 0;
+ struct rw_semaphore *fshared = &current->mm->mmap_sem;
+
+again:
+ mutex_lock(&lguest_lock);
+ down_read(fshared);
+ if (get_futex_key((u32 __user *)ukey, fshared, &key) != 0) {
+ kill_guest(lg, "bad sending DMA key");
+ goto unlock;
+ }
+ /* Shared mapping? Look for other guests... */
+ if (key.shared.offset & 1) {
+ struct lguest_dma_info *i;
+ list_for_each_entry(i, &dma_hash[hash(&key)], list) {
+ if (i->guestid == lg->guestid)
+ continue;
+ if (!key_eq(&key, &i->key))
+ continue;
+
+ empty += dma_transfer(lg, udma, i);
+ break;
+ }
+ if (empty == 1) {
+ /* Give any recipients one chance to restock. */
+ up_read(&current->mm->mmap_sem);
+ mutex_unlock(&lguest_lock);
+ empty++;
+ goto again;
+ }
+ } else {
+ /* Private mapping: tell our userspace. */
+ lg->dma_is_pending = 1;
+ lg->pending_dma = udma;
+ lg->pending_key = ukey;
+ }
+unlock:
+ up_read(fshared);
+ mutex_unlock(&lguest_lock);
+}
+
+void release_all_dma(struct lguest *lg)
+{
+ unsigned int i;
+
+ BUG_ON(!mutex_is_locked(&lguest_lock));
+
+ down_read(&lg->mm->mmap_sem);
+ for (i = 0; i < LGUEST_MAX_DMA; i++) {
+ if (lg->dma[i].interrupt)
+ unlink_dma(&lg->dma[i]);
+ }
+ up_read(&lg->mm->mmap_sem);
+}
+
+/* Userspace wants a dma buffer from this guest. */
+unsigned long get_dma_buffer(struct lguest *lg,
+ unsigned long ukey, unsigned long *interrupt)
+{
+ unsigned long ret = 0;
+ union futex_key key;
+ struct lguest_dma_info *i;
+ struct rw_semaphore *fshared = &current->mm->mmap_sem;
+
+ mutex_lock(&lguest_lock);
+ down_read(fshared);
+ if (get_futex_key((u32 __user *)ukey, fshared, &key) != 0) {
+ kill_guest(lg, "bad registered DMA buffer");
+ goto unlock;
+ }
+ list_for_each_entry(i, &dma_hash[hash(&key)], list) {
+ if (key_eq(&key, &i->key) && i->guestid == lg->guestid) {
+ unsigned int j;
+ for (j = 0; j < i->num_dmas; j++) {
+ struct lguest_dma dma;
+
+ ret = i->dmas + j * sizeof(struct lguest_dma);
+ lgread(lg, &dma, ret, sizeof(dma));
+ if (dma.used_len == 0)
+ break;
+ }
+ *interrupt = i->interrupt;
+ break;
+ }
+ }
+unlock:
+ up_read(fshared);
+ mutex_unlock(&lguest_lock);
+ return ret;
+}
+
diff --git a/drivers/lguest/lg.h b/drivers/lguest/lg.h
new file mode 100644
index 00000000000..3e2ddfbc816
--- /dev/null
+++ b/drivers/lguest/lg.h
@@ -0,0 +1,261 @@
+#ifndef _LGUEST_H
+#define _LGUEST_H
+
+#include <asm/desc.h>
+
+#define GDT_ENTRY_LGUEST_CS 10
+#define GDT_ENTRY_LGUEST_DS 11
+#define LGUEST_CS (GDT_ENTRY_LGUEST_CS * 8)
+#define LGUEST_DS (GDT_ENTRY_LGUEST_DS * 8)
+
+#ifndef __ASSEMBLY__
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/stringify.h>
+#include <linux/binfmts.h>
+#include <linux/futex.h>
+#include <linux/lguest.h>
+#include <linux/lguest_launcher.h>
+#include <linux/wait.h>
+#include <linux/err.h>
+#include <asm/semaphore.h>
+#include "irq_vectors.h"
+
+#define GUEST_PL 1
+
+struct lguest_regs
+{
+ /* Manually saved part. */
+ unsigned long ebx, ecx, edx;
+ unsigned long esi, edi, ebp;
+ unsigned long gs;
+ unsigned long eax;
+ unsigned long fs, ds, es;
+ unsigned long trapnum, errcode;
+ /* Trap pushed part */
+ unsigned long eip;
+ unsigned long cs;
+ unsigned long eflags;
+ unsigned long esp;
+ unsigned long ss;
+};
+
+void free_pagetables(void);
+int init_pagetables(struct page **switcher_page, unsigned int pages);
+
+/* Full 4G segment descriptors, suitable for CS and DS. */
+#define FULL_EXEC_SEGMENT ((struct desc_struct){0x0000ffff, 0x00cf9b00})
+#define FULL_SEGMENT ((struct desc_struct){0x0000ffff, 0x00cf9300})
+
+struct lguest_dma_info
+{
+ struct list_head list;
+ union futex_key key;
+ unsigned long dmas;
+ u16 next_dma;
+ u16 num_dmas;
+ u16 guestid;
+ u8 interrupt; /* 0 when not registered */
+};
+
+/* We have separate types for the guest's ptes & pgds and the shadow ptes &
+ * pgds. Since this host might use three-level pagetables and the guest and
+ * shadow pagetables don't, we can't use the normal pte_t/pgd_t. */
+typedef union {
+ struct { unsigned flags:12, pfn:20; };
+ struct { unsigned long val; } raw;
+} spgd_t;
+typedef union {
+ struct { unsigned flags:12, pfn:20; };
+ struct { unsigned long val; } raw;
+} spte_t;
+typedef union {
+ struct { unsigned flags:12, pfn:20; };
+ struct { unsigned long val; } raw;
+} gpgd_t;
+typedef union {
+ struct { unsigned flags:12, pfn:20; };
+ struct { unsigned long val; } raw;
+} gpte_t;
+#define mkgpte(_val) ((gpte_t){.raw.val = _val})
+#define mkgpgd(_val) ((gpgd_t){.raw.val = _val})
+
+struct pgdir
+{
+ unsigned long cr3;
+ spgd_t *pgdir;
+};
+
+/* This is a guest-specific page (mapped ro) into the guest. */
+struct lguest_ro_state
+{
+ /* Host information we need to restore when we switch back. */
+ u32 host_cr3;
+ struct Xgt_desc_struct host_idt_desc;
+ struct Xgt_desc_struct host_gdt_desc;
+ u32 host_sp;
+
+ /* Fields which are used when guest is running. */
+ struct Xgt_desc_struct guest_idt_desc;
+ struct Xgt_desc_struct guest_gdt_desc;
+ struct i386_hw_tss guest_tss;
+ struct desc_struct guest_idt[IDT_ENTRIES];
+ struct desc_struct guest_gdt[GDT_ENTRIES];
+};
+
+/* We have two pages shared with guests, per cpu. */
+struct lguest_pages
+{
+ /* This is the stack page mapped rw in guest */
+ char spare[PAGE_SIZE - sizeof(struct lguest_regs)];
+ struct lguest_regs regs;
+
+ /* This is the host state & guest descriptor page, ro in guest */
+ struct lguest_ro_state state;
+} __attribute__((aligned(PAGE_SIZE)));
+
+#define CHANGED_IDT 1
+#define CHANGED_GDT 2
+#define CHANGED_GDT_TLS 4 /* Actually a subset of CHANGED_GDT */
+#define CHANGED_ALL 3
+
+/* The private info the thread maintains about the guest. */
+struct lguest
+{
+ /* At end of a page shared mapped over lguest_pages in guest. */
+ unsigned long regs_page;
+ struct lguest_regs *regs;
+ struct lguest_data __user *lguest_data;
+ struct task_struct *tsk;
+ struct mm_struct *mm; /* == tsk->mm, but that becomes NULL on exit */
+ u16 guestid;
+ u32 pfn_limit;
+ u32 page_offset;
+ u32 cr2;
+ int halted;
+ int ts;
+ u32 next_hcall;
+ u32 esp1;
+ u8 ss1;
+
+ /* Do we need to stop what we're doing and return to userspace? */
+ int break_out;
+ wait_queue_head_t break_wq;
+
+ /* Bitmap of what has changed: see CHANGED_* above. */
+ int changed;
+ struct lguest_pages *last_pages;
+
+ /* We keep a small number of these. */
+ u32 pgdidx;
+ struct pgdir pgdirs[4];
+
+ /* Cached wakeup: we hold a reference to this task. */
+ struct task_struct *wake;
+
+ unsigned long noirq_start, noirq_end;
+ int dma_is_pending;
+ unsigned long pending_dma; /* struct lguest_dma */
+ unsigned long pending_key; /* address they're sending to */
+
+ unsigned int stack_pages;
+ u32 tsc_khz;
+
+ struct lguest_dma_info dma[LGUEST_MAX_DMA];
+
+ /* Dead? */
+ const char *dead;
+
+ /* The GDT entries copied into lguest_ro_state when running. */
+ struct desc_struct gdt[GDT_ENTRIES];
+
+ /* The IDT entries: some copied into lguest_ro_state when running. */
+ struct desc_struct idt[FIRST_EXTERNAL_VECTOR+LGUEST_IRQS];
+ struct desc_struct syscall_idt;
+
+ /* Virtual clock device */
+ struct hrtimer hrt;
+
+ /* Pending virtual interrupts */
+ DECLARE_BITMAP(irqs_pending, LGUEST_IRQS);
+};
+
+extern struct lguest lguests[];
+extern struct mutex lguest_lock;
+
+/* core.c: */
+u32 lgread_u32(struct lguest *lg, unsigned long addr);
+void lgwrite_u32(struct lguest *lg, unsigned long addr, u32 val);
+void lgread(struct lguest *lg, void *buf, unsigned long addr, unsigned len);
+void lgwrite(struct lguest *lg, unsigned long, const void *buf, unsigned len);
+int find_free_guest(void);
+int lguest_address_ok(const struct lguest *lg,
+ unsigned long addr, unsigned long len);
+int run_guest(struct lguest *lg, unsigned long __user *user);
+
+
+/* interrupts_and_traps.c: */
+void maybe_do_interrupt(struct lguest *lg);
+int deliver_trap(struct lguest *lg, unsigned int num);
+void load_guest_idt_entry(struct lguest *lg, unsigned int i, u32 low, u32 hi);
+void guest_set_stack(struct lguest *lg, u32 seg, u32 esp, unsigned int pages);
+void pin_stack_pages(struct lguest *lg);
+void setup_default_idt_entries(struct lguest_ro_state *state,
+ const unsigned long *def);
+void copy_traps(const struct lguest *lg, struct desc_struct *idt,
+ const unsigned long *def);
+void guest_set_clockevent(struct lguest *lg, unsigned long delta);
+void init_clockdev(struct lguest *lg);
+
+/* segments.c: */
+void setup_default_gdt_entries(struct lguest_ro_state *state);
+void setup_guest_gdt(struct lguest *lg);
+void load_guest_gdt(struct lguest *lg, unsigned long table, u32 num);
+void guest_load_tls(struct lguest *lg, unsigned long tls_array);
+void copy_gdt(const struct lguest *lg, struct desc_struct *gdt);
+void copy_gdt_tls(const struct lguest *lg, struct desc_struct *gdt);
+
+/* page_tables.c: */
+int init_guest_pagetable(struct lguest *lg, unsigned long pgtable);
+void free_guest_pagetable(struct lguest *lg);
+void guest_new_pagetable(struct lguest *lg, unsigned long pgtable);
+void guest_set_pmd(struct lguest *lg, unsigned long cr3, u32 i);
+void guest_pagetable_clear_all(struct lguest *lg);
+void guest_pagetable_flush_user(struct lguest *lg);
+void guest_set_pte(struct lguest *lg, unsigned long cr3,
+ unsigned long vaddr, gpte_t val);
+void map_switcher_in_guest(struct lguest *lg, struct lguest_pages *pages);
+int demand_page(struct lguest *info, unsigned long cr2, int errcode);
+void pin_page(struct lguest *lg, unsigned long vaddr);
+
+/* lguest_user.c: */
+int lguest_device_init(void);
+void lguest_device_remove(void);
+
+/* io.c: */
+void lguest_io_init(void);
+int bind_dma(struct lguest *lg,
+ unsigned long key, unsigned long udma, u16 numdmas, u8 interrupt);
+void send_dma(struct lguest *info, unsigned long key, unsigned long udma);
+void release_all_dma(struct lguest *lg);
+unsigned long get_dma_buffer(struct lguest *lg, unsigned long key,
+ unsigned long *interrupt);
+
+/* hypercalls.c: */
+void do_hypercalls(struct lguest *lg);
+
+#define kill_guest(lg, fmt...) \
+do { \
+ if (!(lg)->dead) { \
+ (lg)->dead = kasprintf(GFP_ATOMIC, fmt); \
+ if (!(lg)->dead) \
+ (lg)->dead = ERR_PTR(-ENOMEM); \
+ } \
+} while(0)
+
+static inline unsigned long guest_pa(struct lguest *lg, unsigned long vaddr)
+{
+ return vaddr - lg->page_offset;
+}
+#endif /* __ASSEMBLY__ */
+#endif /* _LGUEST_H */
diff --git a/drivers/lguest/lguest.c b/drivers/lguest/lguest.c
index b3a72bd8d6f..b9a58b78c99 100644
--- a/drivers/lguest/lguest.c
+++ b/drivers/lguest/lguest.c
@@ -25,6 +25,8 @@
#include <linux/screen_info.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
#include <linux/lguest.h>
#include <linux/lguest_launcher.h>
#include <linux/lguest_bus.h>
@@ -37,6 +39,7 @@
#include <asm/e820.h>
#include <asm/mce.h>
#include <asm/io.h>
+//#include <asm/sched-clock.h>
/* Declarations for definitions in lguest_guest.S */
extern char lguest_noirq_start[], lguest_noirq_end[];
@@ -54,7 +57,6 @@ struct lguest_data lguest_data = {
.blocked_interrupts = { 1 }, /* Block timer interrupts */
};
struct lguest_device_desc *lguest_devices;
-static __initdata const struct lguest_boot_info *boot = __va(0);
static enum paravirt_lazy_mode lazy_mode;
static void lguest_lazy_mode(enum paravirt_lazy_mode mode)
@@ -210,7 +212,7 @@ static void lguest_cpuid(unsigned int *eax, unsigned int *ebx,
case 1: /* Basic feature request. */
/* We only allow kernel to see SSE3, CMPXCHG16B and SSSE3 */
*ecx &= 0x00002201;
- /* Similarly: SSE, SSE2, FXSR, MMX, CMOV, CMPXCHG8B, FPU. */
+ /* SSE, SSE2, FXSR, MMX, CMOV, CMPXCHG8B, FPU. */
*edx &= 0x07808101;
/* Host wants to know when we flush kernel pages: set PGE. */
*edx |= 0x00002000;
@@ -346,24 +348,104 @@ static unsigned long lguest_get_wallclock(void)
return hcall(LHCALL_GET_WALLCLOCK, 0, 0, 0);
}
+static cycle_t lguest_clock_read(void)
+{
+ if (lguest_data.tsc_khz)
+ return native_read_tsc();
+ else
+ return jiffies;
+}
+
+/* This is what we tell the kernel is our clocksource. */
+static struct clocksource lguest_clock = {
+ .name = "lguest",
+ .rating = 400,
+ .read = lguest_clock_read,
+};
+
+/* We also need a "struct clock_event_device": Linux asks us to set it to go
+ * off some time in the future. Actually, James Morris figured all this out, I
+ * just applied the patch. */
+static int lguest_clockevent_set_next_event(unsigned long delta,
+ struct clock_event_device *evt)
+{
+ if (delta < LG_CLOCK_MIN_DELTA) {
+ if (printk_ratelimit())
+ printk(KERN_DEBUG "%s: small delta %lu ns\n",
+ __FUNCTION__, delta);
+ return -ETIME;
+ }
+ hcall(LHCALL_SET_CLOCKEVENT, delta, 0, 0);
+ return 0;
+}
+
+static void lguest_clockevent_set_mode(enum clock_event_mode mode,
+ struct clock_event_device *evt)
+{
+ switch (mode) {
+ case CLOCK_EVT_MODE_UNUSED:
+ case CLOCK_EVT_MODE_SHUTDOWN:
+ /* A 0 argument shuts the clock down. */
+ hcall(LHCALL_SET_CLOCKEVENT, 0, 0, 0);
+ break;
+ case CLOCK_EVT_MODE_ONESHOT:
+ /* This is what we expect. */
+ break;
+ case CLOCK_EVT_MODE_PERIODIC:
+ BUG();
+ }
+}
+
+/* This describes our primitive timer chip. */
+static struct clock_event_device lguest_clockevent = {
+ .name = "lguest",
+ .features = CLOCK_EVT_FEAT_ONESHOT,
+ .set_next_event = lguest_clockevent_set_next_event,
+ .set_mode = lguest_clockevent_set_mode,
+ .rating = INT_MAX,
+ .mult = 1,
+ .shift = 0,
+ .min_delta_ns = LG_CLOCK_MIN_DELTA,
+ .max_delta_ns = LG_CLOCK_MAX_DELTA,
+};
+
+/* This is the Guest timer interrupt handler (hardware interrupt 0). We just
+ * call the clockevent infrastructure and it does whatever needs doing. */
static void lguest_time_irq(unsigned int irq, struct irq_desc *desc)
{
- do_timer(hcall(LHCALL_TIMER_READ, 0, 0, 0));
- update_process_times(user_mode_vm(get_irq_regs()));
+ unsigned long flags;
+
+ /* Don't interrupt us while this is running. */
+ local_irq_save(flags);
+ lguest_clockevent.event_handler(&lguest_clockevent);
+ local_irq_restore(flags);
}
-static u64 sched_clock_base;
static void lguest_time_init(void)
{
set_irq_handler(0, lguest_time_irq);
- hcall(LHCALL_TIMER_READ, 0, 0, 0);
- sched_clock_base = jiffies_64;
- enable_lguest_irq(0);
-}
-static unsigned long long lguest_sched_clock(void)
-{
- return (jiffies_64 - sched_clock_base) * (1000000000 / HZ);
+ /* We use the TSC if the Host tells us we can, otherwise a dumb
+ * jiffies-based clock. */
+ if (lguest_data.tsc_khz) {
+ lguest_clock.shift = 22;
+ lguest_clock.mult = clocksource_khz2mult(lguest_data.tsc_khz,
+ lguest_clock.shift);
+ lguest_clock.mask = CLOCKSOURCE_MASK(64);
+ lguest_clock.flags = CLOCK_SOURCE_IS_CONTINUOUS;
+ } else {
+ /* To understand this, start at kernel/time/jiffies.c... */
+ lguest_clock.shift = 8;
+ lguest_clock.mult = (((u64)NSEC_PER_SEC<<8)/ACTHZ) << 8;
+ lguest_clock.mask = CLOCKSOURCE_MASK(32);
+ }
+ clocksource_register(&lguest_clock);
+
+ /* We can't set cpumask in the initializer: damn C limitations! */
+ lguest_clockevent.cpumask = cpumask_of_cpu(0);
+ clockevents_register_device(&lguest_clockevent);
+
+ enable_lguest_irq(0);
}
static void lguest_load_esp0(struct tss_struct *tss,
@@ -418,8 +500,7 @@ static __init char *lguest_memory_setup(void)
/* We do this here because lockcheck barfs if before start_kernel */
atomic_notifier_chain_register(&panic_notifier_list, &paniced);
- e820.nr_map = 0;
- add_memory_region(0, PFN_PHYS(boot->max_pfn), E820_RAM);
+ add_memory_region(E820_MAP->addr, E820_MAP->size, E820_MAP->type);
return "LGUEST";
}
@@ -450,8 +531,13 @@ static unsigned lguest_patch(u8 type, u16 clobber, void *insns, unsigned len)
return insn_len;
}
-__init void lguest_init(void)
+__init void lguest_init(void *boot)
{
+ /* Copy boot parameters first. */
+ memcpy(&boot_params, boot, PARAM_SIZE);
+ memcpy(boot_command_line, __va(boot_params.hdr.cmd_line_ptr),
+ COMMAND_LINE_SIZE);
+
paravirt_ops.name = "lguest";
paravirt_ops.paravirt_enabled = 1;
paravirt_ops.kernel_rpl = 1;
@@ -498,10 +584,8 @@ __init void lguest_init(void)
paravirt_ops.time_init = lguest_time_init;
paravirt_ops.set_lazy_mode = lguest_lazy_mode;
paravirt_ops.wbinvd = lguest_wbinvd;
- paravirt_ops.sched_clock = lguest_sched_clock;
hcall(LHCALL_LGUEST_INIT, __pa(&lguest_data), 0, 0);
- strncpy(boot_command_line, boot->cmdline, COMMAND_LINE_SIZE);
/* We use top of mem for initial pagetables. */
init_pg_tables_end = __pa(pg0);
@@ -532,13 +616,6 @@ __init void lguest_init(void)
add_preferred_console("hvc", 0, NULL);
- if (boot->initrd_size) {
- /* We stash this at top of memory. */
- INITRD_START = boot->max_pfn*PAGE_SIZE - boot->initrd_size;
- INITRD_SIZE = boot->initrd_size;
- LOADER_TYPE = 0xFF;
- }
-
pm_power_off = lguest_power_off;
start_kernel();
}
diff --git a/drivers/lguest/lguest_asm.S b/drivers/lguest/lguest_asm.S
index 5ac3d20bb18..00046c57b5b 100644
--- a/drivers/lguest/lguest_asm.S
+++ b/drivers/lguest/lguest_asm.S
@@ -10,7 +10,8 @@
* This is where we begin: we have a magic signature which the launcher looks
* for. The plan is that the Linux boot protocol will be extended with a
* "platform type" field which will guide us here from the normal entry point,
- * but for the moment this suffices.
+ * but for the moment this suffices. We pass the virtual address of the boot
+ * info to lguest_init().
*
* We put it in .init.text will be discarded after boot.
*/
@@ -18,6 +19,8 @@
.ascii "GenuineLguest"
/* Set up initial stack. */
movl $(init_thread_union+THREAD_SIZE),%esp
+ movl %esi, %eax
+ addl $__PAGE_OFFSET, %eax
jmp lguest_init
/* The templates for inline patching. */
diff --git a/drivers/lguest/lguest_user.c b/drivers/lguest/lguest_user.c
new file mode 100644
index 00000000000..e90d7a783da
--- /dev/null
+++ b/drivers/lguest/lguest_user.c
@@ -0,0 +1,236 @@
+/* Userspace control of the guest, via /dev/lguest. */
+#include <linux/uaccess.h>
+#include <linux/miscdevice.h>
+#include <linux/fs.h>
+#include "lg.h"
+
+static void setup_regs(struct lguest_regs *regs, unsigned long start)
+{
+ /* Write out stack in format lguest expects, so we can switch to it. */
+ regs->ds = regs->es = regs->ss = __KERNEL_DS|GUEST_PL;
+ regs->cs = __KERNEL_CS|GUEST_PL;
+ regs->eflags = 0x202; /* Interrupts enabled. */
+ regs->eip = start;
+ /* esi points to our boot information (physical address 0) */
+}
+
+/* + addr */
+static long user_get_dma(struct lguest *lg, const u32 __user *input)
+{
+ unsigned long key, udma, irq;
+
+ if (get_user(key, input) != 0)
+ return -EFAULT;
+ udma = get_dma_buffer(lg, key, &irq);
+ if (!udma)
+ return -ENOENT;
+
+ /* We put irq number in udma->used_len. */
+ lgwrite_u32(lg, udma + offsetof(struct lguest_dma, used_len), irq);
+ return udma;
+}
+
+/* To force the Guest to stop running and return to the Launcher, the
+ * Waker sets writes LHREQ_BREAK and the value "1" to /dev/lguest. The
+ * Launcher then writes LHREQ_BREAK and "0" to release the Waker. */
+static int break_guest_out(struct lguest *lg, const u32 __user *input)
+{
+ unsigned long on;
+
+ /* Fetch whether they're turning break on or off.. */
+ if (get_user(on, input) != 0)
+ return -EFAULT;
+
+ if (on) {
+ lg->break_out = 1;
+ /* Pop it out (may be running on different CPU) */
+ wake_up_process(lg->tsk);
+ /* Wait for them to reset it */
+ return wait_event_interruptible(lg->break_wq, !lg->break_out);
+ } else {
+ lg->break_out = 0;
+ wake_up(&lg->break_wq);
+ return 0;
+ }
+}
+
+/* + irq */
+static int user_send_irq(struct lguest *lg, const u32 __user *input)
+{
+ u32 irq;
+
+ if (get_user(irq, input) != 0)
+ return -EFAULT;
+ if (irq >= LGUEST_IRQS)
+ return -EINVAL;
+ set_bit(irq, lg->irqs_pending);
+ return 0;
+}
+
+static ssize_t read(struct file *file, char __user *user, size_t size,loff_t*o)
+{
+ struct lguest *lg = file->private_data;
+
+ if (!lg)
+ return -EINVAL;
+
+ /* If you're not the task which owns the guest, go away. */
+ if (current != lg->tsk)
+ return -EPERM;
+
+ if (lg->dead) {
+ size_t len;
+
+ if (IS_ERR(lg->dead))
+ return PTR_ERR(lg->dead);
+
+ len = min(size, strlen(lg->dead)+1);
+ if (copy_to_user(user, lg->dead, len) != 0)
+ return -EFAULT;
+ return len;
+ }
+
+ if (lg->dma_is_pending)
+ lg->dma_is_pending = 0;
+
+ return run_guest(lg, (unsigned long __user *)user);
+}
+
+/* Take: pfnlimit, pgdir, start, pageoffset. */
+static int initialize(struct file *file, const u32 __user *input)
+{
+ struct lguest *lg;
+ int err, i;
+ u32 args[4];
+
+ /* We grab the Big Lguest lock, which protects the global array
+ * "lguests" and multiple simultaneous initializations. */
+ mutex_lock(&lguest_lock);
+
+ if (file->private_data) {
+ err = -EBUSY;
+ goto unlock;
+ }
+
+ if (copy_from_user(args, input, sizeof(args)) != 0) {
+ err = -EFAULT;
+ goto unlock;
+ }
+
+ i = find_free_guest();
+ if (i < 0) {
+ err = -ENOSPC;
+ goto unlock;
+ }
+ lg = &lguests[i];
+ lg->guestid = i;
+ lg->pfn_limit = args[0];
+ lg->page_offset = args[3];
+ lg->regs_page = get_zeroed_page(GFP_KERNEL);
+ if (!lg->regs_page) {
+ err = -ENOMEM;
+ goto release_guest;
+ }
+ lg->regs = (void *)lg->regs_page + PAGE_SIZE - sizeof(*lg->regs);
+
+ err = init_guest_pagetable(lg, args[1]);
+ if (err)
+ goto free_regs;
+
+ setup_regs(lg->regs, args[2]);
+ setup_guest_gdt(lg);
+ init_clockdev(lg);
+ lg->tsk = current;
+ lg->mm = get_task_mm(lg->tsk);
+ init_waitqueue_head(&lg->break_wq);
+ lg->last_pages = NULL;
+ file->private_data = lg;
+
+ mutex_unlock(&lguest_lock);
+
+ return sizeof(args);
+
+free_regs:
+ free_page(lg->regs_page);
+release_guest:
+ memset(lg, 0, sizeof(*lg));
+unlock:
+ mutex_unlock(&lguest_lock);
+ return err;
+}
+
+static ssize_t write(struct file *file, const char __user *input,
+ size_t size, loff_t *off)
+{
+ struct lguest *lg = file->private_data;
+ u32 req;
+
+ if (get_user(req, input) != 0)
+ return -EFAULT;
+ input += sizeof(req);
+
+ if (req != LHREQ_INITIALIZE && !lg)
+ return -EINVAL;
+ if (lg && lg->dead)
+ return -ENOENT;
+
+ /* If you're not the task which owns the Guest, you can only break */
+ if (lg && current != lg->tsk && req != LHREQ_BREAK)
+ return -EPERM;
+
+ switch (req) {
+ case LHREQ_INITIALIZE:
+ return initialize(file, (const u32 __user *)input);
+ case LHREQ_GETDMA:
+ return user_get_dma(lg, (const u32 __user *)input);
+ case LHREQ_IRQ:
+ return user_send_irq(lg, (const u32 __user *)input);
+ case LHREQ_BREAK:
+ return break_guest_out(lg, (const u32 __user *)input);
+ default:
+ return -EINVAL;
+ }
+}
+
+static int close(struct inode *inode, struct file *file)
+{
+ struct lguest *lg = file->private_data;
+
+ if (!lg)
+ return 0;
+
+ mutex_lock(&lguest_lock);
+ /* Cancels the hrtimer set via LHCALL_SET_CLOCKEVENT. */
+ hrtimer_cancel(&lg->hrt);
+ release_all_dma(lg);
+ free_guest_pagetable(lg);
+ mmput(lg->mm);
+ if (!IS_ERR(lg->dead))
+ kfree(lg->dead);
+ free_page(lg->regs_page);
+ memset(lg, 0, sizeof(*lg));
+ mutex_unlock(&lguest_lock);
+ return 0;
+}
+
+static struct file_operations lguest_fops = {
+ .owner = THIS_MODULE,
+ .release = close,
+ .write = write,
+ .read = read,
+};
+static struct miscdevice lguest_dev = {
+ .minor = MISC_DYNAMIC_MINOR,
+ .name = "lguest",
+ .fops = &lguest_fops,
+};
+
+int __init lguest_device_init(void)
+{
+ return misc_register(&lguest_dev);
+}
+
+void __exit lguest_device_remove(void)
+{
+ misc_deregister(&lguest_dev);
+}
diff --git a/drivers/lguest/page_tables.c b/drivers/lguest/page_tables.c
new file mode 100644
index 00000000000..1b0ba09b126
--- /dev/null
+++ b/drivers/lguest/page_tables.c
@@ -0,0 +1,411 @@
+/* Shadow page table operations.
+ * Copyright (C) Rusty Russell IBM Corporation 2006.
+ * GPL v2 and any later version */
+#include <linux/mm.h>
+#include <linux/types.h>
+#include <linux/spinlock.h>
+#include <linux/random.h>
+#include <linux/percpu.h>
+#include <asm/tlbflush.h>
+#include "lg.h"
+
+#define PTES_PER_PAGE_SHIFT 10
+#define PTES_PER_PAGE (1 << PTES_PER_PAGE_SHIFT)
+#define SWITCHER_PGD_INDEX (PTES_PER_PAGE - 1)
+
+static DEFINE_PER_CPU(spte_t *, switcher_pte_pages);
+#define switcher_pte_page(cpu) per_cpu(switcher_pte_pages, cpu)
+
+static unsigned vaddr_to_pgd_index(unsigned long vaddr)
+{
+ return vaddr >> (PAGE_SHIFT + PTES_PER_PAGE_SHIFT);
+}
+
+/* These access the shadow versions (ie. the ones used by the CPU). */
+static spgd_t *spgd_addr(struct lguest *lg, u32 i, unsigned long vaddr)
+{
+ unsigned int index = vaddr_to_pgd_index(vaddr);
+
+ if (index >= SWITCHER_PGD_INDEX) {
+ kill_guest(lg, "attempt to access switcher pages");
+ index = 0;
+ }
+ return &lg->pgdirs[i].pgdir[index];
+}
+
+static spte_t *spte_addr(struct lguest *lg, spgd_t spgd, unsigned long vaddr)
+{
+ spte_t *page = __va(spgd.pfn << PAGE_SHIFT);
+ BUG_ON(!(spgd.flags & _PAGE_PRESENT));
+ return &page[(vaddr >> PAGE_SHIFT) % PTES_PER_PAGE];
+}
+
+/* These access the guest versions. */
+static unsigned long gpgd_addr(struct lguest *lg, unsigned long vaddr)
+{
+ unsigned int index = vaddr >> (PAGE_SHIFT + PTES_PER_PAGE_SHIFT);
+ return lg->pgdirs[lg->pgdidx].cr3 + index * sizeof(gpgd_t);
+}
+
+static unsigned long gpte_addr(struct lguest *lg,
+ gpgd_t gpgd, unsigned long vaddr)
+{
+ unsigned long gpage = gpgd.pfn << PAGE_SHIFT;
+ BUG_ON(!(gpgd.flags & _PAGE_PRESENT));
+ return gpage + ((vaddr>>PAGE_SHIFT) % PTES_PER_PAGE) * sizeof(gpte_t);
+}
+
+/* Do a virtual -> physical mapping on a user page. */
+static unsigned long get_pfn(unsigned long virtpfn, int write)
+{
+ struct page *page;
+ unsigned long ret = -1UL;
+
+ down_read(&current->mm->mmap_sem);
+ if (get_user_pages(current, current->mm, virtpfn << PAGE_SHIFT,
+ 1, write, 1, &page, NULL) == 1)
+ ret = page_to_pfn(page);
+ up_read(&current->mm->mmap_sem);
+ return ret;
+}
+
+static spte_t gpte_to_spte(struct lguest *lg, gpte_t gpte, int write)
+{
+ spte_t spte;
+ unsigned long pfn;
+
+ /* We ignore the global flag. */
+ spte.flags = (gpte.flags & ~_PAGE_GLOBAL);
+ pfn = get_pfn(gpte.pfn, write);
+ if (pfn == -1UL) {
+ kill_guest(lg, "failed to get page %u", gpte.pfn);
+ /* Must not put_page() bogus page on cleanup. */
+ spte.flags = 0;
+ }
+ spte.pfn = pfn;
+ return spte;
+}
+
+static void release_pte(spte_t pte)
+{
+ if (pte.flags & _PAGE_PRESENT)
+ put_page(pfn_to_page(pte.pfn));
+}
+
+static void check_gpte(struct lguest *lg, gpte_t gpte)
+{
+ if ((gpte.flags & (_PAGE_PWT|_PAGE_PSE)) || gpte.pfn >= lg->pfn_limit)
+ kill_guest(lg, "bad page table entry");
+}
+
+static void check_gpgd(struct lguest *lg, gpgd_t gpgd)
+{
+ if ((gpgd.flags & ~_PAGE_TABLE) || gpgd.pfn >= lg->pfn_limit)
+ kill_guest(lg, "bad page directory entry");
+}
+
+/* FIXME: We hold reference to pages, which prevents them from being
+ swapped. It'd be nice to have a callback when Linux wants to swap out. */
+
+/* We fault pages in, which allows us to update accessed/dirty bits.
+ * Return true if we got page. */
+int demand_page(struct lguest *lg, unsigned long vaddr, int errcode)
+{
+ gpgd_t gpgd;
+ spgd_t *spgd;
+ unsigned long gpte_ptr;
+ gpte_t gpte;
+ spte_t *spte;
+
+ gpgd = mkgpgd(lgread_u32(lg, gpgd_addr(lg, vaddr)));
+ if (!(gpgd.flags & _PAGE_PRESENT))
+ return 0;
+
+ spgd = spgd_addr(lg, lg->pgdidx, vaddr);
+ if (!(spgd->flags & _PAGE_PRESENT)) {
+ /* Get a page of PTEs for them. */
+ unsigned long ptepage = get_zeroed_page(GFP_KERNEL);
+ /* FIXME: Steal from self in this case? */
+ if (!ptepage) {
+ kill_guest(lg, "out of memory allocating pte page");
+ return 0;
+ }
+ check_gpgd(lg, gpgd);
+ spgd->raw.val = (__pa(ptepage) | gpgd.flags);
+ }
+
+ gpte_ptr = gpte_addr(lg, gpgd, vaddr);
+ gpte = mkgpte(lgread_u32(lg, gpte_ptr));
+
+ /* No page? */
+ if (!(gpte.flags & _PAGE_PRESENT))
+ return 0;
+
+ /* Write to read-only page? */
+ if ((errcode & 2) && !(gpte.flags & _PAGE_RW))
+ return 0;
+
+ /* User access to a non-user page? */
+ if ((errcode & 4) && !(gpte.flags & _PAGE_USER))
+ return 0;
+
+ check_gpte(lg, gpte);
+ gpte.flags |= _PAGE_ACCESSED;
+ if (errcode & 2)
+ gpte.flags |= _PAGE_DIRTY;
+
+ /* We're done with the old pte. */
+ spte = spte_addr(lg, *spgd, vaddr);
+ release_pte(*spte);
+
+ /* We don't make it writable if this isn't a write: later
+ * write will fault so we can set dirty bit in guest. */
+ if (gpte.flags & _PAGE_DIRTY)
+ *spte = gpte_to_spte(lg, gpte, 1);
+ else {
+ gpte_t ro_gpte = gpte;
+ ro_gpte.flags &= ~_PAGE_RW;
+ *spte = gpte_to_spte(lg, ro_gpte, 0);
+ }
+
+ /* Now we update dirty/accessed on guest. */
+ lgwrite_u32(lg, gpte_ptr, gpte.raw.val);
+ return 1;
+}
+
+/* This is much faster than the full demand_page logic. */
+static int page_writable(struct lguest *lg, unsigned long vaddr)
+{
+ spgd_t *spgd;
+ unsigned long flags;
+
+ spgd = spgd_addr(lg, lg->pgdidx, vaddr);
+ if (!(spgd->flags & _PAGE_PRESENT))
+ return 0;
+
+ flags = spte_addr(lg, *spgd, vaddr)->flags;
+ return (flags & (_PAGE_PRESENT|_PAGE_RW)) == (_PAGE_PRESENT|_PAGE_RW);
+}
+
+void pin_page(struct lguest *lg, unsigned long vaddr)
+{
+ if (!page_writable(lg, vaddr) && !demand_page(lg, vaddr, 2))
+ kill_guest(lg, "bad stack page %#lx", vaddr);
+}
+
+static void release_pgd(struct lguest *lg, spgd_t *spgd)
+{
+ if (spgd->flags & _PAGE_PRESENT) {
+ unsigned int i;
+ spte_t *ptepage = __va(spgd->pfn << PAGE_SHIFT);
+ for (i = 0; i < PTES_PER_PAGE; i++)
+ release_pte(ptepage[i]);
+ free_page((long)ptepage);
+ spgd->raw.val = 0;
+ }
+}
+
+static void flush_user_mappings(struct lguest *lg, int idx)
+{
+ unsigned int i;
+ for (i = 0; i < vaddr_to_pgd_index(lg->page_offset); i++)
+ release_pgd(lg, lg->pgdirs[idx].pgdir + i);
+}
+
+void guest_pagetable_flush_user(struct lguest *lg)
+{
+ flush_user_mappings(lg, lg->pgdidx);
+}
+
+static unsigned int find_pgdir(struct lguest *lg, unsigned long pgtable)
+{
+ unsigned int i;
+ for (i = 0; i < ARRAY_SIZE(lg->pgdirs); i++)
+ if (lg->pgdirs[i].cr3 == pgtable)
+ break;
+ return i;
+}
+
+static unsigned int new_pgdir(struct lguest *lg,
+ unsigned long cr3,
+ int *blank_pgdir)
+{
+ unsigned int next;
+
+ next = random32() % ARRAY_SIZE(lg->pgdirs);
+ if (!lg->pgdirs[next].pgdir) {
+ lg->pgdirs[next].pgdir = (spgd_t *)get_zeroed_page(GFP_KERNEL);
+ if (!lg->pgdirs[next].pgdir)
+ next = lg->pgdidx;
+ else
+ /* There are no mappings: you'll need to re-pin */
+ *blank_pgdir = 1;
+ }
+ lg->pgdirs[next].cr3 = cr3;
+ /* Release all the non-kernel mappings. */
+ flush_user_mappings(lg, next);
+
+ return next;
+}
+
+void guest_new_pagetable(struct lguest *lg, unsigned long pgtable)
+{
+ int newpgdir, repin = 0;
+
+ newpgdir = find_pgdir(lg, pgtable);
+ if (newpgdir == ARRAY_SIZE(lg->pgdirs))
+ newpgdir = new_pgdir(lg, pgtable, &repin);
+ lg->pgdidx = newpgdir;
+ if (repin)
+ pin_stack_pages(lg);
+}
+
+static void release_all_pagetables(struct lguest *lg)
+{
+ unsigned int i, j;
+
+ for (i = 0; i < ARRAY_SIZE(lg->pgdirs); i++)
+ if (lg->pgdirs[i].pgdir)
+ for (j = 0; j < SWITCHER_PGD_INDEX; j++)
+ release_pgd(lg, lg->pgdirs[i].pgdir + j);
+}
+
+void guest_pagetable_clear_all(struct lguest *lg)
+{
+ release_all_pagetables(lg);
+ pin_stack_pages(lg);
+}
+
+static void do_set_pte(struct lguest *lg, int idx,
+ unsigned long vaddr, gpte_t gpte)
+{
+ spgd_t *spgd = spgd_addr(lg, idx, vaddr);
+ if (spgd->flags & _PAGE_PRESENT) {
+ spte_t *spte = spte_addr(lg, *spgd, vaddr);
+ release_pte(*spte);
+ if (gpte.flags & (_PAGE_DIRTY | _PAGE_ACCESSED)) {
+ check_gpte(lg, gpte);
+ *spte = gpte_to_spte(lg, gpte, gpte.flags&_PAGE_DIRTY);
+ } else
+ spte->raw.val = 0;
+ }
+}
+
+void guest_set_pte(struct lguest *lg,
+ unsigned long cr3, unsigned long vaddr, gpte_t gpte)
+{
+ /* Kernel mappings must be changed on all top levels. */
+ if (vaddr >= lg->page_offset) {
+ unsigned int i;
+ for (i = 0; i < ARRAY_SIZE(lg->pgdirs); i++)
+ if (lg->pgdirs[i].pgdir)
+ do_set_pte(lg, i, vaddr, gpte);
+ } else {
+ int pgdir = find_pgdir(lg, cr3);
+ if (pgdir != ARRAY_SIZE(lg->pgdirs))
+ do_set_pte(lg, pgdir, vaddr, gpte);
+ }
+}
+
+void guest_set_pmd(struct lguest *lg, unsigned long cr3, u32 idx)
+{
+ int pgdir;
+
+ if (idx >= SWITCHER_PGD_INDEX)
+ return;
+
+ pgdir = find_pgdir(lg, cr3);
+ if (pgdir < ARRAY_SIZE(lg->pgdirs))
+ release_pgd(lg, lg->pgdirs[pgdir].pgdir + idx);
+}
+
+int init_guest_pagetable(struct lguest *lg, unsigned long pgtable)
+{
+ /* We assume this in flush_user_mappings, so check now */
+ if (vaddr_to_pgd_index(lg->page_offset) >= SWITCHER_PGD_INDEX)
+ return -EINVAL;
+ lg->pgdidx = 0;
+ lg->pgdirs[lg->pgdidx].cr3 = pgtable;
+ lg->pgdirs[lg->pgdidx].pgdir = (spgd_t*)get_zeroed_page(GFP_KERNEL);
+ if (!lg->pgdirs[lg->pgdidx].pgdir)
+ return -ENOMEM;
+ return 0;
+}
+
+void free_guest_pagetable(struct lguest *lg)
+{
+ unsigned int i;
+
+ release_all_pagetables(lg);
+ for (i = 0; i < ARRAY_SIZE(lg->pgdirs); i++)
+ free_page((long)lg->pgdirs[i].pgdir);
+}
+
+/* Caller must be preempt-safe */
+void map_switcher_in_guest(struct lguest *lg, struct lguest_pages *pages)
+{
+ spte_t *switcher_pte_page = __get_cpu_var(switcher_pte_pages);
+ spgd_t switcher_pgd;
+ spte_t regs_pte;
+
+ /* Since switcher less that 4MB, we simply mug top pte page. */
+ switcher_pgd.pfn = __pa(switcher_pte_page) >> PAGE_SHIFT;
+ switcher_pgd.flags = _PAGE_KERNEL;
+ lg->pgdirs[lg->pgdidx].pgdir[SWITCHER_PGD_INDEX] = switcher_pgd;
+
+ /* Map our regs page over stack page. */
+ regs_pte.pfn = __pa(lg->regs_page) >> PAGE_SHIFT;
+ regs_pte.flags = _PAGE_KERNEL;
+ switcher_pte_page[(unsigned long)pages/PAGE_SIZE%PTES_PER_PAGE]
+ = regs_pte;
+}
+
+static void free_switcher_pte_pages(void)
+{
+ unsigned int i;
+
+ for_each_possible_cpu(i)
+ free_page((long)switcher_pte_page(i));
+}
+
+static __init void populate_switcher_pte_page(unsigned int cpu,
+ struct page *switcher_page[],
+ unsigned int pages)
+{
+ unsigned int i;
+ spte_t *pte = switcher_pte_page(cpu);
+
+ for (i = 0; i < pages; i++) {
+ pte[i].pfn = page_to_pfn(switcher_page[i]);
+ pte[i].flags = _PAGE_PRESENT|_PAGE_ACCESSED;
+ }
+
+ /* We only map this CPU's pages, so guest can't see others. */
+ i = pages + cpu*2;
+
+ /* First page (regs) is rw, second (state) is ro. */
+ pte[i].pfn = page_to_pfn(switcher_page[i]);
+ pte[i].flags = _PAGE_PRESENT|_PAGE_ACCESSED|_PAGE_RW;
+ pte[i+1].pfn = page_to_pfn(switcher_page[i+1]);
+ pte[i+1].flags = _PAGE_PRESENT|_PAGE_ACCESSED;
+}
+
+__init int init_pagetables(struct page **switcher_page, unsigned int pages)
+{
+ unsigned int i;
+
+ for_each_possible_cpu(i) {
+ switcher_pte_page(i) = (spte_t *)get_zeroed_page(GFP_KERNEL);
+ if (!switcher_pte_page(i)) {
+ free_switcher_pte_pages();
+ return -ENOMEM;
+ }
+ populate_switcher_pte_page(i, switcher_page, pages);
+ }
+ return 0;
+}
+
+void free_pagetables(void)
+{
+ free_switcher_pte_pages();
+}
diff --git a/drivers/lguest/segments.c b/drivers/lguest/segments.c
new file mode 100644
index 00000000000..1b2cfe89dcd
--- /dev/null
+++ b/drivers/lguest/segments.c
@@ -0,0 +1,125 @@
+#include "lg.h"
+
+static int desc_ok(const struct desc_struct *gdt)
+{
+ /* MBZ=0, P=1, DT=1 */
+ return ((gdt->b & 0x00209000) == 0x00009000);
+}
+
+static int segment_present(const struct desc_struct *gdt)
+{
+ return gdt->b & 0x8000;
+}
+
+static int ignored_gdt(unsigned int num)
+{
+ return (num == GDT_ENTRY_TSS
+ || num == GDT_ENTRY_LGUEST_CS
+ || num == GDT_ENTRY_LGUEST_DS
+ || num == GDT_ENTRY_DOUBLEFAULT_TSS);
+}
+
+/* We don't allow removal of CS, DS or SS; it doesn't make sense. */
+static void check_segment_use(struct lguest *lg, unsigned int desc)
+{
+ if (lg->regs->gs / 8 == desc)
+ lg->regs->gs = 0;
+ if (lg->regs->fs / 8 == desc)
+ lg->regs->fs = 0;
+ if (lg->regs->es / 8 == desc)
+ lg->regs->es = 0;
+ if (lg->regs->ds / 8 == desc
+ || lg->regs->cs / 8 == desc
+ || lg->regs->ss / 8 == desc)
+ kill_guest(lg, "Removed live GDT entry %u", desc);
+}
+
+static void fixup_gdt_table(struct lguest *lg, unsigned start, unsigned end)
+{
+ unsigned int i;
+
+ for (i = start; i < end; i++) {
+ /* We never copy these ones to real gdt */
+ if (ignored_gdt(i))
+ continue;
+
+ /* We could fault in switch_to_guest if they are using
+ * a removed segment. */
+ if (!segment_present(&lg->gdt[i])) {
+ check_segment_use(lg, i);
+ continue;
+ }
+
+ if (!desc_ok(&lg->gdt[i]))
+ kill_guest(lg, "Bad GDT descriptor %i", i);
+
+ /* DPL 0 presumably means "for use by guest". */
+ if ((lg->gdt[i].b & 0x00006000) == 0)
+ lg->gdt[i].b |= (GUEST_PL << 13);
+
+ /* Set accessed bit, since gdt isn't writable. */
+ lg->gdt[i].b |= 0x00000100;
+ }
+}
+
+void setup_default_gdt_entries(struct lguest_ro_state *state)
+{
+ struct desc_struct *gdt = state->guest_gdt;
+ unsigned long tss = (unsigned long)&state->guest_tss;
+
+ /* Hypervisor segments. */
+ gdt[GDT_ENTRY_LGUEST_CS] = FULL_EXEC_SEGMENT;
+ gdt[GDT_ENTRY_LGUEST_DS] = FULL_SEGMENT;
+
+ /* This is the one which we *cannot* copy from guest, since tss
+ is depended on this lguest_ro_state, ie. this cpu. */
+ gdt[GDT_ENTRY_TSS].a = 0x00000067 | (tss << 16);
+ gdt[GDT_ENTRY_TSS].b = 0x00008900 | (tss & 0xFF000000)
+ | ((tss >> 16) & 0x000000FF);
+}
+
+void setup_guest_gdt(struct lguest *lg)
+{
+ lg->gdt[GDT_ENTRY_KERNEL_CS] = FULL_EXEC_SEGMENT;
+ lg->gdt[GDT_ENTRY_KERNEL_DS] = FULL_SEGMENT;
+ lg->gdt[GDT_ENTRY_KERNEL_CS].b |= (GUEST_PL << 13);
+ lg->gdt[GDT_ENTRY_KERNEL_DS].b |= (GUEST_PL << 13);
+}
+
+/* This is a fast version for the common case where only the three TLS entries
+ * have changed. */
+void copy_gdt_tls(const struct lguest *lg, struct desc_struct *gdt)
+{
+ unsigned int i;
+
+ for (i = GDT_ENTRY_TLS_MIN; i <= GDT_ENTRY_TLS_MAX; i++)
+ gdt[i] = lg->gdt[i];
+}
+
+void copy_gdt(const struct lguest *lg, struct desc_struct *gdt)
+{
+ unsigned int i;
+
+ for (i = 0; i < GDT_ENTRIES; i++)
+ if (!ignored_gdt(i))
+ gdt[i] = lg->gdt[i];
+}
+
+void load_guest_gdt(struct lguest *lg, unsigned long table, u32 num)
+{
+ if (num > ARRAY_SIZE(lg->gdt))
+ kill_guest(lg, "too many gdt entries %i", num);
+
+ lgread(lg, lg->gdt, table, num * sizeof(lg->gdt[0]));
+ fixup_gdt_table(lg, 0, ARRAY_SIZE(lg->gdt));
+ lg->changed |= CHANGED_GDT;
+}
+
+void guest_load_tls(struct lguest *lg, unsigned long gtls)
+{
+ struct desc_struct *tls = &lg->gdt[GDT_ENTRY_TLS_MIN];
+
+ lgread(lg, tls, gtls, sizeof(*tls)*GDT_ENTRY_TLS_ENTRIES);
+ fixup_gdt_table(lg, GDT_ENTRY_TLS_MIN, GDT_ENTRY_TLS_MAX+1);
+ lg->changed |= CHANGED_GDT_TLS;
+}
diff --git a/drivers/lguest/switcher.S b/drivers/lguest/switcher.S
new file mode 100644
index 00000000000..eadd4cc299d
--- /dev/null
+++ b/drivers/lguest/switcher.S
@@ -0,0 +1,159 @@
+/* This code sits at 0xFFC00000 to do the low-level guest<->host switch.
+
+ There is are two pages above us for this CPU (struct lguest_pages).
+ The second page (struct lguest_ro_state) becomes read-only after the
+ context switch. The first page (the stack for traps) remains writable,
+ but while we're in here, the guest cannot be running.
+*/
+#include <linux/linkage.h>
+#include <asm/asm-offsets.h>
+#include "lg.h"
+
+.text
+ENTRY(start_switcher_text)
+
+/* %eax points to lguest pages for this CPU. %ebx contains cr3 value.
+ All normal registers can be clobbered! */
+ENTRY(switch_to_guest)
+ /* Save host segments on host stack. */
+ pushl %es
+ pushl %ds
+ pushl %gs
+ pushl %fs
+ /* With CONFIG_FRAME_POINTER, gcc doesn't let us clobber this! */
+ pushl %ebp
+ /* Save host stack. */
+ movl %esp, LGUEST_PAGES_host_sp(%eax)
+ /* Switch to guest stack: if we get NMI we expect to be there. */
+ movl %eax, %edx
+ addl $LGUEST_PAGES_regs, %edx
+ movl %edx, %esp
+ /* Switch to guest's GDT, IDT. */
+ lgdt LGUEST_PAGES_guest_gdt_desc(%eax)
+ lidt LGUEST_PAGES_guest_idt_desc(%eax)
+ /* Switch to guest's TSS while GDT still writable. */
+ movl $(GDT_ENTRY_TSS*8), %edx
+ ltr %dx
+ /* Set host's TSS GDT entry to available (clear byte 5 bit 2). */
+ movl (LGUEST_PAGES_host_gdt_desc+2)(%eax), %edx
+ andb $0xFD, (GDT_ENTRY_TSS*8 + 5)(%edx)
+ /* Switch to guest page tables: lguest_pages->state now read-only. */
+ movl %ebx, %cr3
+ /* Restore guest regs */
+ popl %ebx
+ popl %ecx
+ popl %edx
+ popl %esi
+ popl %edi
+ popl %ebp
+ popl %gs
+ popl %eax
+ popl %fs
+ popl %ds
+ popl %es
+ /* Skip error code and trap number */
+ addl $8, %esp
+ iret
+
+#define SWITCH_TO_HOST \
+ /* Save guest state */ \
+ pushl %es; \
+ pushl %ds; \
+ pushl %fs; \
+ pushl %eax; \
+ pushl %gs; \
+ pushl %ebp; \
+ pushl %edi; \
+ pushl %esi; \
+ pushl %edx; \
+ pushl %ecx; \
+ pushl %ebx; \
+ /* Load lguest ds segment for convenience. */ \
+ movl $(LGUEST_DS), %eax; \
+ movl %eax, %ds; \
+ /* Figure out where we are, based on stack (at top of regs). */ \
+ movl %esp, %eax; \
+ subl $LGUEST_PAGES_regs, %eax; \
+ /* Put trap number in %ebx before we switch cr3 and lose it. */ \
+ movl LGUEST_PAGES_regs_trapnum(%eax), %ebx; \
+ /* Switch to host page tables (host GDT, IDT and stack are in host \
+ mem, so need this first) */ \
+ movl LGUEST_PAGES_host_cr3(%eax), %edx; \
+ movl %edx, %cr3; \
+ /* Set guest's TSS to available (clear byte 5 bit 2). */ \
+ andb $0xFD, (LGUEST_PAGES_guest_gdt+GDT_ENTRY_TSS*8+5)(%eax); \
+ /* Switch to host's GDT & IDT. */ \
+ lgdt LGUEST_PAGES_host_gdt_desc(%eax); \
+ lidt LGUEST_PAGES_host_idt_desc(%eax); \
+ /* Switch to host's stack. */ \
+ movl LGUEST_PAGES_host_sp(%eax), %esp; \
+ /* Switch to host's TSS */ \
+ movl $(GDT_ENTRY_TSS*8), %edx; \
+ ltr %dx; \
+ popl %ebp; \
+ popl %fs; \
+ popl %gs; \
+ popl %ds; \
+ popl %es
+
+/* Return to run_guest_once. */
+return_to_host:
+ SWITCH_TO_HOST
+ iret
+
+deliver_to_host:
+ SWITCH_TO_HOST
+ /* Decode IDT and jump to hosts' irq handler. When that does iret, it
+ * will return to run_guest_once. This is a feature. */
+ movl (LGUEST_PAGES_host_idt_desc+2)(%eax), %edx
+ leal (%edx,%ebx,8), %eax
+ movzwl (%eax),%edx
+ movl 4(%eax), %eax
+ xorw %ax, %ax
+ orl %eax, %edx
+ jmp *%edx
+
+/* Real hardware interrupts are delivered straight to the host. Others
+ cause us to return to run_guest_once so it can decide what to do. Note
+ that some of these are overridden by the guest to deliver directly, and
+ never enter here (see load_guest_idt_entry). */
+.macro IRQ_STUB N TARGET
+ .data; .long 1f; .text; 1:
+ /* Make an error number for most traps, which don't have one. */
+ .if (\N <> 8) && (\N < 10 || \N > 14) && (\N <> 17)
+ pushl $0
+ .endif
+ pushl $\N
+ jmp \TARGET
+ ALIGN
+.endm
+
+.macro IRQ_STUBS FIRST LAST TARGET
+ irq=\FIRST
+ .rept \LAST-\FIRST+1
+ IRQ_STUB irq \TARGET
+ irq=irq+1
+ .endr
+.endm
+
+/* We intercept every interrupt, because we may need to switch back to
+ * host. Unfortunately we can't tell them apart except by entry
+ * point, so we need 256 entry points.
+ */
+.data
+.global default_idt_entries
+default_idt_entries:
+.text
+ IRQ_STUBS 0 1 return_to_host /* First two traps */
+ IRQ_STUB 2 handle_nmi /* NMI */
+ IRQ_STUBS 3 31 return_to_host /* Rest of traps */
+ IRQ_STUBS 32 127 deliver_to_host /* Real interrupts */
+ IRQ_STUB 128 return_to_host /* System call (overridden) */
+ IRQ_STUBS 129 255 deliver_to_host /* Other real interrupts */
+
+/* We ignore NMI and return. */
+handle_nmi:
+ addl $8, %esp
+ iret
+
+ENTRY(end_switcher_text)
diff --git a/include/asm-i386/tsc.h b/include/asm-i386/tsc.h
index 62c091ffccc..a4d806610b7 100644
--- a/include/asm-i386/tsc.h
+++ b/include/asm-i386/tsc.h
@@ -63,6 +63,7 @@ extern void tsc_init(void);
extern void mark_tsc_unstable(char *reason);
extern int unsynchronized_tsc(void);
extern void init_tsc_clocksource(void);
+int check_tsc_unstable(void);
/*
* Boot-time check whether the TSCs are synchronized across
diff --git a/include/linux/lguest.h b/include/linux/lguest.h
index f30c04fc22b..500aace21ca 100644
--- a/include/linux/lguest.h
+++ b/include/linux/lguest.h
@@ -3,11 +3,6 @@
#ifndef _ASM_LGUEST_H
#define _ASM_LGUEST_H
-/* These are randomly chosen numbers which indicate we're an lguest at boot */
-#define LGUEST_MAGIC_EBP 0x4C687970
-#define LGUEST_MAGIC_EDI 0x652D4D65
-#define LGUEST_MAGIC_ESI 0xFFFFFFFF
-
#ifndef __ASSEMBLY__
#include <asm/irq.h>
@@ -20,7 +15,7 @@
#define LHCALL_LOAD_IDT_ENTRY 6
#define LHCALL_SET_STACK 7
#define LHCALL_TS 8
-#define LHCALL_TIMER_READ 9
+#define LHCALL_SET_CLOCKEVENT 9
#define LHCALL_HALT 10
#define LHCALL_GET_WALLCLOCK 11
#define LHCALL_BIND_DMA 12
@@ -29,6 +24,9 @@
#define LHCALL_SET_PMD 15
#define LHCALL_LOAD_TLS 16
+#define LG_CLOCK_MIN_DELTA 100UL
+#define LG_CLOCK_MAX_DELTA ULONG_MAX
+
#define LGUEST_TRAP_ENTRY 0x1F
static inline unsigned long
@@ -75,6 +73,8 @@ struct lguest_data
unsigned long reserve_mem;
/* ID of this guest (used by network driver to set ethernet address) */
u16 guestid;
+ /* KHz for the TSC clock. */
+ u32 tsc_khz;
/* Fields initialized by the guest at boot: */
/* Instruction range to suppress interrupts even if enabled */
diff --git a/include/linux/lguest_launcher.h b/include/linux/lguest_launcher.h
new file mode 100644
index 00000000000..0ba414a40c8
--- /dev/null
+++ b/include/linux/lguest_launcher.h
@@ -0,0 +1,73 @@
+#ifndef _ASM_LGUEST_USER
+#define _ASM_LGUEST_USER
+/* Everything the "lguest" userspace program needs to know. */
+/* They can register up to 32 arrays of lguest_dma. */
+#define LGUEST_MAX_DMA 32
+/* At most we can dma 16 lguest_dma in one op. */
+#define LGUEST_MAX_DMA_SECTIONS 16
+
+/* How many devices? Assume each one wants up to two dma arrays per device. */
+#define LGUEST_MAX_DEVICES (LGUEST_MAX_DMA/2)
+
+struct lguest_dma
+{
+ /* 0 if free to be used, filled by hypervisor. */
+ u32 used_len;
+ unsigned long addr[LGUEST_MAX_DMA_SECTIONS];
+ u16 len[LGUEST_MAX_DMA_SECTIONS];
+};
+
+struct lguest_block_page
+{
+ /* 0 is a read, 1 is a write. */
+ int type;
+ u32 sector; /* Offset in device = sector * 512. */
+ u32 bytes; /* Length expected to be read/written in bytes */
+ /* 0 = pending, 1 = done, 2 = done, error */
+ int result;
+ u32 num_sectors; /* Disk length = num_sectors * 512 */
+};
+
+/* There is a shared page of these. */
+struct lguest_net
+{
+ /* Simply the mac address (with multicast bit meaning promisc). */
+ unsigned char mac[6];
+};
+
+/* Where the Host expects the Guest to SEND_DMA console output to. */
+#define LGUEST_CONSOLE_DMA_KEY 0
+
+/* We have a page of these descriptors in the lguest_device page. */
+struct lguest_device_desc {
+ u16 type;
+#define LGUEST_DEVICE_T_CONSOLE 1
+#define LGUEST_DEVICE_T_NET 2
+#define LGUEST_DEVICE_T_BLOCK 3
+
+ u16 features;
+#define LGUEST_NET_F_NOCSUM 0x4000 /* Don't bother checksumming */
+#define LGUEST_DEVICE_F_RANDOMNESS 0x8000 /* IRQ is fairly random */
+
+ u16 status;
+/* 256 and above are device specific. */
+#define LGUEST_DEVICE_S_ACKNOWLEDGE 1 /* We have seen device. */
+#define LGUEST_DEVICE_S_DRIVER 2 /* We have found a driver */
+#define LGUEST_DEVICE_S_DRIVER_OK 4 /* Driver says OK! */
+#define LGUEST_DEVICE_S_REMOVED 8 /* Device has gone away. */
+#define LGUEST_DEVICE_S_REMOVED_ACK 16 /* Driver has been told. */
+#define LGUEST_DEVICE_S_FAILED 128 /* Something actually failed */
+
+ u16 num_pages;
+ u32 pfn;
+};
+
+/* Write command first word is a request. */
+enum lguest_req
+{
+ LHREQ_INITIALIZE, /* + pfnlimit, pgdir, start, pageoffset */
+ LHREQ_GETDMA, /* + addr (returns &lguest_dma, irq in ->used_len) */
+ LHREQ_IRQ, /* + irq */
+ LHREQ_BREAK, /* + on/off flag (on blocks until someone does off) */
+};
+#endif /* _ASM_LGUEST_USER */
diff --git a/kernel/fork.c b/kernel/fork.c
index e7a2d995b08..46983899822 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -127,7 +127,6 @@ void __put_task_struct(struct task_struct *tsk)
if (!profile_handoff_task(tsk))
free_task(tsk);
}
-EXPORT_SYMBOL_GPL(__put_task_struct);
void __init fork_init(unsigned long mempages)
{
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-28 08:22:12 +0000