diff options
| -rw-r--r-- | target/arm/cpu.h | 2 | ||||
| -rw-r--r-- | target/arm/kvm.c | 30 | ||||
| -rw-r--r-- | target/arm/kvm32.c | 34 | ||||
| -rw-r--r-- | target/arm/kvm64.c | 49 | ||||
| -rw-r--r-- | target/arm/kvm_arm.h | 10 |
5 files changed, 124 insertions, 1 deletions
diff --git a/target/arm/cpu.h b/target/arm/cpu.h index cf99dcca9f..9e8ed423ea 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -573,6 +573,8 @@ typedef struct CPUARMState { uint64_t esr; } serror; + uint8_t ext_dabt_raised; /* Tracking/verifying injection of ext DABT */ + /* State of our input IRQ/FIQ/VIRQ/VFIQ lines */ uint32_t irq_line_state; diff --git a/target/arm/kvm.c b/target/arm/kvm.c index 3a46f54f1f..8bb7318378 100644 --- a/target/arm/kvm.c +++ b/target/arm/kvm.c @@ -749,6 +749,29 @@ int kvm_get_vcpu_events(ARMCPU *cpu) void kvm_arch_pre_run(CPUState *cs, struct kvm_run *run) { + ARMCPU *cpu = ARM_CPU(cs); + CPUARMState *env = &cpu->env; + + if (unlikely(env->ext_dabt_raised)) { + /* + * Verifying that the ext DABT has been properly injected, + * otherwise risking indefinitely re-running the faulting instruction + * Covering a very narrow case for kernels 5.5..5.5.4 + * when injected abort was misconfigured to be + * an IMPLEMENTATION DEFINED exception (for 32-bit EL1) + */ + if (!arm_feature(env, ARM_FEATURE_AARCH64) && + unlikely(!kvm_arm_verify_ext_dabt_pending(cs))) { + + error_report("Data abort exception with no valid ISS generated by " + "guest memory access. KVM unable to emulate faulting " + "instruction. Failed to inject an external data abort " + "into the guest."); + abort(); + } + /* Clear the status */ + env->ext_dabt_raised = 0; + } } MemTxAttrs kvm_arch_post_run(CPUState *cs, struct kvm_run *run) @@ -833,6 +856,8 @@ void kvm_arm_vm_state_change(void *opaque, int running, RunState state) static int kvm_arm_handle_dabt_nisv(CPUState *cs, uint64_t esr_iss, uint64_t fault_ipa) { + ARMCPU *cpu = ARM_CPU(cs); + CPUARMState *env = &cpu->env; /* * Request KVM to inject the external data abort into the guest */ @@ -847,7 +872,10 @@ static int kvm_arm_handle_dabt_nisv(CPUState *cs, uint64_t esr_iss, */ events.exception.ext_dabt_pending = 1; /* KVM_CAP_ARM_INJECT_EXT_DABT implies KVM_CAP_VCPU_EVENTS */ - return kvm_vcpu_ioctl(cs, KVM_SET_VCPU_EVENTS, &events); + if (!kvm_vcpu_ioctl(cs, KVM_SET_VCPU_EVENTS, &events)) { + env->ext_dabt_raised = 1; + return 0; + } } else { error_report("Data abort exception triggered by guest memory access " "at physical address: 0x" TARGET_FMT_lx, diff --git a/target/arm/kvm32.c b/target/arm/kvm32.c index 7b3a19e9ae..0af46b41c8 100644 --- a/target/arm/kvm32.c +++ b/target/arm/kvm32.c @@ -559,3 +559,37 @@ void kvm_arm_pmu_init(CPUState *cs) { qemu_log_mask(LOG_UNIMP, "%s: not implemented\n", __func__); } + +#define ARM_REG_DFSR ARM_CP15_REG32(0, 5, 0, 0) +#define ARM_REG_TTBCR ARM_CP15_REG32(0, 2, 0, 2) +/* + *DFSR: + * TTBCR.EAE == 0 + * FS[4] - DFSR[10] + * FS[3:0] - DFSR[3:0] + * TTBCR.EAE == 1 + * FS, bits [5:0] + */ +#define DFSR_FSC(lpae, v) \ + ((lpae) ? ((v) & 0x3F) : (((v) >> 6) | ((v) & 0x1F))) + +#define DFSC_EXTABT(lpae) ((lpae) ? 0x10 : 0x08) + +bool kvm_arm_verify_ext_dabt_pending(CPUState *cs) +{ + uint32_t dfsr_val; + + if (!kvm_get_one_reg(cs, ARM_REG_DFSR, &dfsr_val)) { + ARMCPU *cpu = ARM_CPU(cs); + CPUARMState *env = &cpu->env; + uint32_t ttbcr; + int lpae = 0; + + if (!kvm_get_one_reg(cs, ARM_REG_TTBCR, &ttbcr)) { + lpae = arm_feature(env, ARM_FEATURE_LPAE) && (ttbcr & TTBCR_EAE); + } + /* The verification is based on FS filed of the DFSR reg only*/ + return (DFSR_FSC(lpae, dfsr_val) == DFSC_EXTABT(lpae)); + } + return false; +} diff --git a/target/arm/kvm64.c b/target/arm/kvm64.c index 3dc494aaa7..1169237905 100644 --- a/target/arm/kvm64.c +++ b/target/arm/kvm64.c @@ -1493,3 +1493,52 @@ bool kvm_arm_handle_debug(CPUState *cs, struct kvm_debug_exit_arch *debug_exit) return false; } + +#define ARM64_REG_ESR_EL1 ARM64_SYS_REG(3, 0, 5, 2, 0) +#define ARM64_REG_TCR_EL1 ARM64_SYS_REG(3, 0, 2, 0, 2) + +/* + * ESR_EL1 + * ISS encoding + * AARCH64: DFSC, bits [5:0] + * AARCH32: + * TTBCR.EAE == 0 + * FS[4] - DFSR[10] + * FS[3:0] - DFSR[3:0] + * TTBCR.EAE == 1 + * FS, bits [5:0] + */ +#define ESR_DFSC(aarch64, lpae, v) \ + ((aarch64 || (lpae)) ? ((v) & 0x3F) \ + : (((v) >> 6) | ((v) & 0x1F))) + +#define ESR_DFSC_EXTABT(aarch64, lpae) \ + ((aarch64) ? 0x10 : (lpae) ? 0x10 : 0x8) + +bool kvm_arm_verify_ext_dabt_pending(CPUState *cs) +{ + uint64_t dfsr_val; + + if (!kvm_get_one_reg(cs, ARM64_REG_ESR_EL1, &dfsr_val)) { + ARMCPU *cpu = ARM_CPU(cs); + CPUARMState *env = &cpu->env; + int aarch64_mode = arm_feature(env, ARM_FEATURE_AARCH64); + int lpae = 0; + + if (!aarch64_mode) { + uint64_t ttbcr; + + if (!kvm_get_one_reg(cs, ARM64_REG_TCR_EL1, &ttbcr)) { + lpae = arm_feature(env, ARM_FEATURE_LPAE) + && (ttbcr & TTBCR_EAE); + } + } + /* + * The verification here is based on the DFSC bits + * of the ESR_EL1 reg only + */ + return (ESR_DFSC(aarch64_mode, lpae, dfsr_val) == + ESR_DFSC_EXTABT(aarch64_mode, lpae)); + } + return false; +} diff --git a/target/arm/kvm_arm.h b/target/arm/kvm_arm.h index a4ce4fd93d..adb38514bf 100644 --- a/target/arm/kvm_arm.h +++ b/target/arm/kvm_arm.h @@ -450,6 +450,16 @@ struct kvm_guest_debug_arch; void kvm_arm_copy_hw_debug_data(struct kvm_guest_debug_arch *ptr); /** + * kvm_arm_verify_ext_dabt_pending: + * @cs: CPUState + * + * Verify the fault status code wrt the Ext DABT injection + * + * Returns: true if the fault status code is as expected, false otherwise + */ +bool kvm_arm_verify_ext_dabt_pending(CPUState *cs); + +/** * its_class_name: * * Return the ITS class name to use depending on whether KVM acceleration |