KVM: x86: Return to userspace with internal error on unexpected exit reason

Receiving an unexpected exit reason from hardware should be considered
as a severe bug in KVM. Therefore, instead of just injecting #UD to
guest and ignore it, exit to userspace on internal error so that
it could handle it properly (probably by terminating guest).

In addition, prefer to use vcpu_unimpl() instead of WARN_ONCE()
as handling unexpected exit reason should be a rare unexpected
event (that was expected to never happen) and we prefer to print
a message on it every time it occurs to guest.

Furthermore, dump VMCS/VMCB to dmesg to assist diagnosing such cases.

Reviewed-by: Mihai Carabas <mihai.carabas@oracle.com>
Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com>
Reviewed-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Liran Alon
2019-08-26 13:16:43 +03:00
committed by Paolo Bonzini
parent 1edce0a9eb
commit 7396d337cf
3 changed files with 17 additions and 5 deletions

View File

@@ -243,6 +243,8 @@ struct kvm_hyperv_exit {
#define KVM_INTERNAL_ERROR_SIMUL_EX 2
/* Encounter unexpected vm-exit due to delivery event. */
#define KVM_INTERNAL_ERROR_DELIVERY_EV 3
/* Encounter unexpected vm-exit reason */
#define KVM_INTERNAL_ERROR_UNEXPECTED_EXIT_REASON 4
/* for KVM_RUN, returned by mmap(vcpu_fd, offset=0) */
struct kvm_run {