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authorRichard Henderson <richard.henderson@linaro.org>2020-06-25 20:31:42 -0700
committerPeter Maydell <peter.maydell@linaro.org>2020-06-26 14:31:12 +0100
commite4d5bf4fbd5abfc3727e711eda64a583cab4d637 (patch)
treec47caec8dd879af6eea694ba619af8bfe286057a /target/arm/mte_helper.c
parent8bce44a2f6beb388a3f157652b46e99929839a96 (diff)
downloadqemu-arm-e4d5bf4fbd5abfc3727e711eda64a583cab4d637.tar.gz
target/arm: Add allocation tag storage for system mode
Look up the physical address for the given virtual address, convert that to a tag physical address, and finally return the host address that backs it. Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20200626033144.790098-45-richard.henderson@linaro.org Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'target/arm/mte_helper.c')
-rw-r--r--target/arm/mte_helper.c131
1 files changed, 131 insertions, 0 deletions
diff --git a/target/arm/mte_helper.c b/target/arm/mte_helper.c
index 4f9bd3add3..5ea57d487a 100644
--- a/target/arm/mte_helper.c
+++ b/target/arm/mte_helper.c
@@ -21,6 +21,7 @@
#include "cpu.h"
#include "internals.h"
#include "exec/exec-all.h"
+#include "exec/ram_addr.h"
#include "exec/cpu_ldst.h"
#include "exec/helper-proto.h"
@@ -74,8 +75,138 @@ static uint8_t *allocation_tag_mem(CPUARMState *env, int ptr_mmu_idx,
int ptr_size, MMUAccessType tag_access,
int tag_size, uintptr_t ra)
{
+#ifdef CONFIG_USER_ONLY
/* Tag storage not implemented. */
return NULL;
+#else
+ uintptr_t index;
+ CPUIOTLBEntry *iotlbentry;
+ int in_page, flags;
+ ram_addr_t ptr_ra;
+ hwaddr ptr_paddr, tag_paddr, xlat;
+ MemoryRegion *mr;
+ ARMASIdx tag_asi;
+ AddressSpace *tag_as;
+ void *host;
+
+ /*
+ * Probe the first byte of the virtual address. This raises an
+ * exception for inaccessible pages, and resolves the virtual address
+ * into the softmmu tlb.
+ *
+ * When RA == 0, this is for mte_probe1. The page is expected to be
+ * valid. Indicate to probe_access_flags no-fault, then assert that
+ * we received a valid page.
+ */
+ flags = probe_access_flags(env, ptr, ptr_access, ptr_mmu_idx,
+ ra == 0, &host, ra);
+ assert(!(flags & TLB_INVALID_MASK));
+
+ /*
+ * Find the iotlbentry for ptr. This *must* be present in the TLB
+ * because we just found the mapping.
+ * TODO: Perhaps there should be a cputlb helper that returns a
+ * matching tlb entry + iotlb entry.
+ */
+ index = tlb_index(env, ptr_mmu_idx, ptr);
+# ifdef CONFIG_DEBUG_TCG
+ {
+ CPUTLBEntry *entry = tlb_entry(env, ptr_mmu_idx, ptr);
+ target_ulong comparator = (ptr_access == MMU_DATA_LOAD
+ ? entry->addr_read
+ : tlb_addr_write(entry));
+ g_assert(tlb_hit(comparator, ptr));
+ }
+# endif
+ iotlbentry = &env_tlb(env)->d[ptr_mmu_idx].iotlb[index];
+
+ /* If the virtual page MemAttr != Tagged, access unchecked. */
+ if (!arm_tlb_mte_tagged(&iotlbentry->attrs)) {
+ return NULL;
+ }
+
+ /*
+ * If not backed by host ram, there is no tag storage: access unchecked.
+ * This is probably a guest os bug though, so log it.
+ */
+ if (unlikely(flags & TLB_MMIO)) {
+ qemu_log_mask(LOG_GUEST_ERROR,
+ "Page @ 0x%" PRIx64 " indicates Tagged Normal memory "
+ "but is not backed by host ram\n", ptr);
+ return NULL;
+ }
+
+ /*
+ * The Normal memory access can extend to the next page. E.g. a single
+ * 8-byte access to the last byte of a page will check only the last
+ * tag on the first page.
+ * Any page access exception has priority over tag check exception.
+ */
+ in_page = -(ptr | TARGET_PAGE_MASK);
+ if (unlikely(ptr_size > in_page)) {
+ void *ignore;
+ flags |= probe_access_flags(env, ptr + in_page, ptr_access,
+ ptr_mmu_idx, ra == 0, &ignore, ra);
+ assert(!(flags & TLB_INVALID_MASK));
+ }
+
+ /* Any debug exception has priority over a tag check exception. */
+ if (unlikely(flags & TLB_WATCHPOINT)) {
+ int wp = ptr_access == MMU_DATA_LOAD ? BP_MEM_READ : BP_MEM_WRITE;
+ assert(ra != 0);
+ cpu_check_watchpoint(env_cpu(env), ptr, ptr_size,
+ iotlbentry->attrs, wp, ra);
+ }
+
+ /*
+ * Find the physical address within the normal mem space.
+ * The memory region lookup must succeed because TLB_MMIO was
+ * not set in the cputlb lookup above.
+ */
+ mr = memory_region_from_host(host, &ptr_ra);
+ tcg_debug_assert(mr != NULL);
+ tcg_debug_assert(memory_region_is_ram(mr));
+ ptr_paddr = ptr_ra;
+ do {
+ ptr_paddr += mr->addr;
+ mr = mr->container;
+ } while (mr);
+
+ /* Convert to the physical address in tag space. */
+ tag_paddr = ptr_paddr >> (LOG2_TAG_GRANULE + 1);
+
+ /* Look up the address in tag space. */
+ tag_asi = iotlbentry->attrs.secure ? ARMASIdx_TagS : ARMASIdx_TagNS;
+ tag_as = cpu_get_address_space(env_cpu(env), tag_asi);
+ mr = address_space_translate(tag_as, tag_paddr, &xlat, NULL,
+ tag_access == MMU_DATA_STORE,
+ iotlbentry->attrs);
+
+ /*
+ * Note that @mr will never be NULL. If there is nothing in the address
+ * space at @tag_paddr, the translation will return the unallocated memory
+ * region. For our purposes, the result must be ram.
+ */
+ if (unlikely(!memory_region_is_ram(mr))) {
+ /* ??? Failure is a board configuration error. */
+ qemu_log_mask(LOG_UNIMP,
+ "Tag Memory @ 0x%" HWADDR_PRIx " not found for "
+ "Normal Memory @ 0x%" HWADDR_PRIx "\n",
+ tag_paddr, ptr_paddr);
+ return NULL;
+ }
+
+ /*
+ * Ensure the tag memory is dirty on write, for migration.
+ * Tag memory can never contain code or display memory (vga).
+ */
+ if (tag_access == MMU_DATA_STORE) {
+ ram_addr_t tag_ra = memory_region_get_ram_addr(mr) + xlat;
+ cpu_physical_memory_set_dirty_flag(tag_ra, DIRTY_MEMORY_MIGRATION);
+ }
+
+ return memory_region_get_ram_ptr(mr) + xlat;
+#endif
}
uint64_t HELPER(irg)(CPUARMState *env, uint64_t rn, uint64_t rm)