diff options
Diffstat (limited to 'arch/powerpc/kvm/44x_tlb.c')
| -rw-r--r-- | arch/powerpc/kvm/44x_tlb.c | 224 |
1 files changed, 224 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/44x_tlb.c b/arch/powerpc/kvm/44x_tlb.c new file mode 100644 index 00000000000..f5d7a5eab96 --- /dev/null +++ b/arch/powerpc/kvm/44x_tlb.c @@ -0,0 +1,224 @@ +/* + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License, version 2, as + * published by the Free Software Foundation. + * + * 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, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * + * Copyright IBM Corp. 2007 + * + * Authors: Hollis Blanchard <hollisb@us.ibm.com> + */ + +#include <linux/types.h> +#include <linux/string.h> +#include <linux/kvm_host.h> +#include <linux/highmem.h> +#include <asm/mmu-44x.h> +#include <asm/kvm_ppc.h> + +#include "44x_tlb.h" + +#define PPC44x_TLB_USER_PERM_MASK (PPC44x_TLB_UX|PPC44x_TLB_UR|PPC44x_TLB_UW) +#define PPC44x_TLB_SUPER_PERM_MASK (PPC44x_TLB_SX|PPC44x_TLB_SR|PPC44x_TLB_SW) + +static unsigned int kvmppc_tlb_44x_pos; + +static u32 kvmppc_44x_tlb_shadow_attrib(u32 attrib, int usermode) +{ + /* Mask off reserved bits. */ + attrib &= PPC44x_TLB_PERM_MASK|PPC44x_TLB_ATTR_MASK; + + if (!usermode) { + /* Guest is in supervisor mode, so we need to translate guest + * supervisor permissions into user permissions. */ + attrib &= ~PPC44x_TLB_USER_PERM_MASK; + attrib |= (attrib & PPC44x_TLB_SUPER_PERM_MASK) << 3; + } + + /* Make sure host can always access this memory. */ + attrib |= PPC44x_TLB_SX|PPC44x_TLB_SR|PPC44x_TLB_SW; + + return attrib; +} + +/* Search the guest TLB for a matching entry. */ +int kvmppc_44x_tlb_index(struct kvm_vcpu *vcpu, gva_t eaddr, unsigned int pid, + unsigned int as) +{ + int i; + + /* XXX Replace loop with fancy data structures. */ + for (i = 0; i < PPC44x_TLB_SIZE; i++) { + struct tlbe *tlbe = &vcpu->arch.guest_tlb[i]; + unsigned int tid; + + if (eaddr < get_tlb_eaddr(tlbe)) + continue; + + if (eaddr > get_tlb_end(tlbe)) + continue; + + tid = get_tlb_tid(tlbe); + if (tid && (tid != pid)) + continue; + + if (!get_tlb_v(tlbe)) + continue; + + if (get_tlb_ts(tlbe) != as) + continue; + + return i; + } + + return -1; +} + +struct tlbe *kvmppc_44x_itlb_search(struct kvm_vcpu *vcpu, gva_t eaddr) +{ + unsigned int as = !!(vcpu->arch.msr & MSR_IS); + unsigned int index; + + index = kvmppc_44x_tlb_index(vcpu, eaddr, vcpu->arch.pid, as); + if (index == -1) + return NULL; + return &vcpu->arch.guest_tlb[index]; +} + +struct tlbe *kvmppc_44x_dtlb_search(struct kvm_vcpu *vcpu, gva_t eaddr) +{ + unsigned int as = !!(vcpu->arch.msr & MSR_DS); + unsigned int index; + + index = kvmppc_44x_tlb_index(vcpu, eaddr, vcpu->arch.pid, as); + if (index == -1) + return NULL; + return &vcpu->arch.guest_tlb[index]; +} + +static int kvmppc_44x_tlbe_is_writable(struct tlbe *tlbe) +{ + return tlbe->word2 & (PPC44x_TLB_SW|PPC44x_TLB_UW); +} + +/* Must be called with mmap_sem locked for writing. */ +static void kvmppc_44x_shadow_release(struct kvm_vcpu *vcpu, + unsigned int index) +{ + struct tlbe *stlbe = &vcpu->arch.shadow_tlb[index]; + struct page *page = vcpu->arch.shadow_pages[index]; + + kunmap(vcpu->arch.shadow_pages[index]); + + if (get_tlb_v(stlbe)) { + if (kvmppc_44x_tlbe_is_writable(stlbe)) + kvm_release_page_dirty(page); + else + kvm_release_page_clean(page); + } +} + +/* Caller must ensure that the specified guest TLB entry is safe to insert into + * the shadow TLB. */ +void kvmppc_mmu_map(struct kvm_vcpu *vcpu, u64 gvaddr, gfn_t gfn, u64 asid, + u32 flags) +{ + struct page *new_page; + struct tlbe *stlbe; + hpa_t hpaddr; + unsigned int victim; + + /* Future optimization: don't overwrite the TLB entry containing the + * current PC (or stack?). */ + victim = kvmppc_tlb_44x_pos++; + if (kvmppc_tlb_44x_pos > tlb_44x_hwater) + kvmppc_tlb_44x_pos = 0; + stlbe = &vcpu->arch.shadow_tlb[victim]; + + /* Get reference to new page. */ + down_write(¤t->mm->mmap_sem); + new_page = gfn_to_page(vcpu->kvm, gfn); + if (is_error_page(new_page)) { + printk(KERN_ERR "Couldn't get guest page!\n"); + kvm_release_page_clean(new_page); + return; + } + hpaddr = page_to_phys(new_page); + + /* Drop reference to old page. */ + kvmppc_44x_shadow_release(vcpu, victim); + up_write(¤t->mm->mmap_sem); + + vcpu->arch.shadow_pages[victim] = new_page; + + /* XXX Make sure (va, size) doesn't overlap any other + * entries. 440x6 user manual says the result would be + * "undefined." */ + + /* XXX what about AS? */ + + stlbe->tid = asid & 0xff; + + /* Force TS=1 for all guest mappings. */ + /* For now we hardcode 4KB mappings, but it will be important to + * use host large pages in the future. */ + stlbe->word0 = (gvaddr & PAGE_MASK) | PPC44x_TLB_VALID | PPC44x_TLB_TS + | PPC44x_TLB_4K; + + stlbe->word1 = (hpaddr & 0xfffffc00) | ((hpaddr >> 32) & 0xf); + stlbe->word2 = kvmppc_44x_tlb_shadow_attrib(flags, + vcpu->arch.msr & MSR_PR); +} + +void kvmppc_mmu_invalidate(struct kvm_vcpu *vcpu, u64 eaddr, u64 asid) +{ + unsigned int pid = asid & 0xff; + int i; + + /* XXX Replace loop with fancy data structures. */ + down_write(¤t->mm->mmap_sem); + for (i = 0; i <= tlb_44x_hwater; i++) { + struct tlbe *stlbe = &vcpu->arch.shadow_tlb[i]; + unsigned int tid; + + if (!get_tlb_v(stlbe)) + continue; + + if (eaddr < get_tlb_eaddr(stlbe)) + continue; + + if (eaddr > get_tlb_end(stlbe)) + continue; + + tid = get_tlb_tid(stlbe); + if (tid && (tid != pid)) + continue; + + kvmppc_44x_shadow_release(vcpu, i); + stlbe->word0 = 0; + } + up_write(¤t->mm->mmap_sem); +} + +/* Invalidate all mappings, so that when they fault back in they will get the + * proper permission bits. */ +void kvmppc_mmu_priv_switch(struct kvm_vcpu *vcpu, int usermode) +{ + int i; + + /* XXX Replace loop with fancy data structures. */ + down_write(¤t->mm->mmap_sem); + for (i = 0; i <= tlb_44x_hwater; i++) { + kvmppc_44x_shadow_release(vcpu, i); + vcpu->arch.shadow_tlb[i].word0 = 0; + } + up_write(¤t->mm->mmap_sem); +} |