[RFC PATCH v5 27/29] KVM: selftests: Propagate KVM_EXIT_MEMORY_FAULT to userspace

[Sagi Shahar]

Allow userspace to handle KVM_EXIT_MEMORY_FAULT instead of triggering
TEST_ASSERT.

>From the KVM_EXIT_MEMORY_FAULT documentation:
Note!  KVM_EXIT_MEMORY_FAULT is unique among all KVM exit reasons in that it
accompanies a return code of '-1', not '0'!  errno will always be set to EFAULT
or EHWPOISON when KVM exits with KVM_EXIT_MEMORY_FAULT, userspace should assume
kvm_run.exit_reason is stale/undefined for all other error numbers.

Signed-off-by: Sagi Shahar <sagis@xxxxxxxxxx>
---
 tools/testing/selftests/kvm/lib/kvm_util.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index d024abc5379c..8fb041e51484 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -1742,6 +1742,10 @@ void vcpu_run(struct kvm_vcpu *vcpu)
 {
 	int ret = _vcpu_run(vcpu);
 
+	// Allow this scenario to be handled by the caller.
+	if (ret == -1 && errno == EFAULT)
+		return;
+
 	TEST_ASSERT(!ret, KVM_IOCTL_ERROR(KVM_RUN, ret));
 }
 
-- 
2.43.0.472.g3155946c3a-goog