Re: [PATCH v4] KVM: arm64: selftests: Check the pending SError state in external_aborts

[Oliver Upton <oupton@kernel.org>]

On Tue, Oct 06, 2026 at 10:28:41AM +0100, Fuad Tabba wrote:
> None of the external abort tests look at the vCPU events once the guest
> is done, so an SError left pending after the guest took it, or dropped
> while the guest had it masked, goes unnoticed.
> 
> Read the vCPU events back at the end of every test that runs the guest.
> The SError must still be pending in the masked case, with the injected
> ESR when the vCPU has RAS, and no SError, injected or spurious, may be
> pending in any of the others.
> 
> Signed-off-by: Fuad Tabba <fuad.tabba@linux.dev>

Reviewed-by: Oliver Upton <oupton@kernel.org>

Thanks,
Oliver

> ---
> The check that no SError is left pending after the guest took it is
> what fails without commit 3708f6342f01 ("KVM: arm64: Sync HCR_EL2.VSE
> back to the host vCPU under pKVM"), in kvmarm/next.
> 
> Changes since v3 [1]:
> - Check the SError pending state at the end of every test that runs the
>   guest, and assert it is still pending, with the injected ESR, in the
>   masked case (Oliver [2]).
> 
> [1] https://lore.kernel.org/all/20261005050349.836795-1-fuad.tabba@linux.dev/
> [2] https://lore.kernel.org/all/asNdAXGkxagm88Su@kernel.org/
> 
>  .../selftests/kvm/arm64/external_aborts.c     | 20 +++++++++++++++++++
>  1 file changed, 20 insertions(+)
> 
> diff --git a/tools/testing/selftests/kvm/arm64/external_aborts.c b/tools/testing/selftests/kvm/arm64/external_aborts.c
> index 7836756a38a6c..1a858d0d82968 100644
> --- a/tools/testing/selftests/kvm/arm64/external_aborts.c
> +++ b/tools/testing/selftests/kvm/arm64/external_aborts.c
> @@ -75,6 +75,17 @@ static void vcpu_inject_serror(struct kvm_vcpu *vcpu)
>  	vcpu_events_set(vcpu, &events);
>  }
>  
> +static void vcpu_assert_serror_pending(struct kvm_vcpu *vcpu, bool pending)
> +{
> +	struct kvm_vcpu_events events;
> +
> +	vcpu_events_get(vcpu, &events);
> +	TEST_ASSERT_EQ(events.exception.serror_pending, pending);
> +
> +	if (pending && vcpu_has_ras(vcpu))
> +		TEST_ASSERT_EQ(events.exception.serror_esr, EXPECTED_SERROR_ISS);
> +}
> +
>  static void __vcpu_run_expect(struct kvm_vcpu *vcpu, unsigned int cmd)
>  {
>  	struct ucall uc;
> @@ -134,6 +145,7 @@ static void test_mmio_abort(void)
>  
>  	vcpu_inject_sea(vcpu);
>  	vcpu_run_expect_done(vcpu);
> +	vcpu_assert_serror_pending(vcpu, false);
>  	kvm_vm_free(vm);
>  }
>  
> @@ -162,6 +174,7 @@ static void test_mmio_nisv(void)
>  
>  	TEST_ASSERT(_vcpu_run(vcpu), "Expected nonzero return code from KVM_RUN");
>  	TEST_ASSERT_EQ(errno, ENOSYS);
> +	vcpu_assert_serror_pending(vcpu, false);
>  
>  	kvm_vm_free(vm);
>  }
> @@ -185,6 +198,7 @@ static void test_mmio_nisv_abort(void)
>  
>  	vcpu_inject_sea(vcpu);
>  	vcpu_run_expect_done(vcpu);
> +	vcpu_assert_serror_pending(vcpu, false);
>  	kvm_vm_free(vm);
>  }
>  
> @@ -212,6 +226,7 @@ static void test_serror_masked(void)
>  
>  	vcpu_inject_serror(vcpu);
>  	vcpu_run_expect_done(vcpu);
> +	vcpu_assert_serror_pending(vcpu, true);
>  	kvm_vm_free(vm);
>  }
>  
> @@ -247,6 +262,7 @@ static void test_serror(void)
>  
>  	vcpu_inject_serror(vcpu);
>  	vcpu_run_expect_done(vcpu);
> +	vcpu_assert_serror_pending(vcpu, false);
>  	kvm_vm_free(vm);
>  }
>  
> @@ -288,6 +304,7 @@ static void test_s1ptw_abort(void)
>  	*ptep |= bad_pa;
>  
>  	vcpu_run_expect_done(vcpu);
> +	vcpu_assert_serror_pending(vcpu, false);
>  	kvm_vm_free(vm);
>  }
>  
> @@ -313,6 +330,7 @@ static void test_serror_emulated(void)
>  	vcpu_run_expect_sync(vcpu);
>  	vcpu_inject_serror(vcpu);
>  	vcpu_run_expect_done(vcpu);
> +	vcpu_assert_serror_pending(vcpu, false);
>  	kvm_vm_free(vm);
>  }
>  
> @@ -356,6 +374,7 @@ static void test_mmio_ease(void)
>  
>  	vcpu_inject_sea(vcpu);
>  	vcpu_run_expect_done(vcpu);
> +	vcpu_assert_serror_pending(vcpu, false);
>  done:
>  	kvm_vm_free(vm);
>  }
> @@ -395,6 +414,7 @@ static void test_serror_amo(void)
>  	vcpu_run_expect_sync(vcpu);
>  	vcpu_inject_serror(vcpu);
>  	vcpu_run_expect_done(vcpu);
> +	vcpu_assert_serror_pending(vcpu, false);
>  	kvm_vm_free(vm);
>  }
>  
> 
> base-commit: fa22cd9947fc245d71bc40482f7f78eb0d5a4af0
> -- 
> 2.39.5
>