From e4d5bf4fbd5abfc3727e711eda64a583cab4d637 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Thu, 25 Jun 2020 20:31:42 -0700 Subject: [PATCH] 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 Message-id: 20200626033144.790098-45-richard.henderson@linaro.org Reviewed-by: Peter Maydell Signed-off-by: Peter Maydell --- target/arm/mte_helper.c | 131 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 131 insertions(+) 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)