From 937f2245596de9026ca8ae017ef47889523c4326 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Mon, 10 Oct 2022 20:18:50 -0700 Subject: [PATCH] target/arm: Use probe_access_full for BTI Add a field to TARGET_PAGE_ENTRY_EXTRA to hold the guarded bit. In is_guarded_page, use probe_access_full instead of just guessing that the tlb entry is still present. Also handles the FIXME about executing from device memory. Reviewed-by: Peter Maydell Signed-off-by: Richard Henderson Message-id: 20221011031911.2408754-4-richard.henderson@linaro.org Signed-off-by: Peter Maydell --- target/arm/cpu-param.h | 9 +++++---- target/arm/cpu.h | 13 ------------- target/arm/internals.h | 1 + target/arm/ptw.c | 7 ++++--- target/arm/translate-a64.c | 21 ++++++++++----------- 5 files changed, 20 insertions(+), 31 deletions(-) diff --git a/target/arm/cpu-param.h b/target/arm/cpu-param.h index 38347b0d20..f4338fd10e 100644 --- a/target/arm/cpu-param.h +++ b/target/arm/cpu-param.h @@ -36,12 +36,13 @@ * * For ARMMMUIdx_Stage2*, pte_attrs is the S2 descriptor bits [5:2]. * Otherwise, pte_attrs is the same as the MAIR_EL1 8-bit format. - * For shareability, as in the SH field of the VMSAv8-64 PTEs. + * For shareability and guarded, as in the SH and GP fields respectively + * of the VMSAv8-64 PTEs. */ # define TARGET_PAGE_ENTRY_EXTRA \ - uint8_t pte_attrs; \ - uint8_t shareability; - + uint8_t pte_attrs; \ + uint8_t shareability; \ + bool guarded; #endif #define NB_MMU_MODES 8 diff --git a/target/arm/cpu.h b/target/arm/cpu.h index 9a358c410b..9df7adbe81 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -3388,19 +3388,6 @@ static inline uint64_t *aa64_vfp_qreg(CPUARMState *env, unsigned regno) /* Shared between translate-sve.c and sve_helper.c. */ extern const uint64_t pred_esz_masks[5]; -/* Helper for the macros below, validating the argument type. */ -static inline MemTxAttrs *typecheck_memtxattrs(MemTxAttrs *x) -{ - return x; -} - -/* - * Lvalue macros for ARM TLB bits that we must cache in the TCG TLB. - * Using these should be a bit more self-documenting than using the - * generic target bits directly. - */ -#define arm_tlb_bti_gp(x) (typecheck_memtxattrs(x)->target_tlb_bit0) - /* * AArch64 usage of the PAGE_TARGET_* bits for linux-user. * Note that with the Linux kernel, PROT_MTE may not be cleared by mprotect diff --git a/target/arm/internals.h b/target/arm/internals.h index 9566364dca..c3c3920ded 100644 --- a/target/arm/internals.h +++ b/target/arm/internals.h @@ -1095,6 +1095,7 @@ typedef struct ARMCacheAttrs { unsigned int attrs:8; unsigned int shareability:2; /* as in the SH field of the VMSAv8-64 PTEs */ bool is_s2_format:1; + bool guarded:1; /* guarded bit of the v8-64 PTE */ } ARMCacheAttrs; /* Fields that are valid upon success. */ diff --git a/target/arm/ptw.c b/target/arm/ptw.c index 23f16f4ff7..2d182d62e5 100644 --- a/target/arm/ptw.c +++ b/target/arm/ptw.c @@ -1313,9 +1313,10 @@ static bool get_phys_addr_lpae(CPUARMState *env, uint64_t address, */ result->f.attrs.secure = false; } - /* When in aarch64 mode, and BTI is enabled, remember GP in the IOTLB. */ - if (aarch64 && guarded && cpu_isar_feature(aa64_bti, cpu)) { - arm_tlb_bti_gp(&result->f.attrs) = true; + + /* When in aarch64 mode, and BTI is enabled, remember GP in the TLB. */ + if (aarch64 && cpu_isar_feature(aa64_bti, cpu)) { + result->f.guarded = guarded; } if (mmu_idx == ARMMMUIdx_Stage2 || mmu_idx == ARMMMUIdx_Stage2_S) { diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c index 5b67375f4e..60ff753d81 100644 --- a/target/arm/translate-a64.c +++ b/target/arm/translate-a64.c @@ -14601,22 +14601,21 @@ static bool is_guarded_page(CPUARMState *env, DisasContext *s) #ifdef CONFIG_USER_ONLY return page_get_flags(addr) & PAGE_BTI; #else + CPUTLBEntryFull *full; + void *host; int mmu_idx = arm_to_core_mmu_idx(s->mmu_idx); - unsigned int index = tlb_index(env, mmu_idx, addr); - CPUTLBEntry *entry = tlb_entry(env, mmu_idx, addr); + int flags; /* * We test this immediately after reading an insn, which means - * that any normal page must be in the TLB. The only exception - * would be for executing from flash or device memory, which - * does not retain the TLB entry. - * - * FIXME: Assume false for those, for now. We could use - * arm_cpu_get_phys_page_attrs_debug to re-read the page - * table entry even for that case. + * that the TLB entry must be present and valid, and thus this + * access will never raise an exception. */ - return (tlb_hit(entry->addr_code, addr) && - arm_tlb_bti_gp(&env_tlb(env)->d[mmu_idx].fulltlb[index].attrs)); + flags = probe_access_full(env, addr, MMU_INST_FETCH, mmu_idx, + false, &host, &full, 0); + assert(!(flags & TLB_INVALID_MASK)); + + return full->guarded; #endif }