diff options
author | Beata Michalska <beata.michalska@linaro.org> | 2020-07-03 16:59:42 +0100 |
---|---|---|
committer | Peter Maydell <peter.maydell@linaro.org> | 2020-07-03 16:59:42 +0100 |
commit | 1711bfa5f5b2b108901813f57246c9ff4a44a50f (patch) | |
tree | 445b909cd5b4a075fc14b94175b274b3266703cc /target/arm/kvm.c | |
parent | 694bcaa81f41b7fc5e07273debe1dc309b3dcf03 (diff) |
target/arm: kvm: Handle misconfigured dabt injection
Injecting external data abort through KVM might trigger
an issue on kernels that do not get updated to include the KVM fix.
For those and aarch32 guests, the injected abort gets misconfigured
to be an implementation defined exception. This leads to the guest
repeatedly re-running the faulting instruction.
Add support for handling that case.
[
Fixed-by: 018f22f95e8a
('KVM: arm: Fix DFSR setting for non-LPAE aarch32 guests')
Fixed-by: 21aecdbd7f3a
('KVM: arm: Make inject_abt32() inject an external abort instead')
]
Signed-off-by: Beata Michalska <beata.michalska@linaro.org>
Acked-by: Andrew Jones <drjones@redhat.com>
Message-id: 20200629114110.30723-3-beata.michalska@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'target/arm/kvm.c')
-rw-r--r-- | target/arm/kvm.c | 30 |
1 files changed, 29 insertions, 1 deletions
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, |