On Fri, Apr 29, 2022, Paolo Bonzini wrote:
> On 4/29/22 19:03, Sean Christopherson wrote:
> > This doesn't even compile...
> >
> > arch/x86/kvm/vmx/nested.c: In function ‘vmx_has_nested_events’:
> > arch/x86/kvm/vmx/nested.c:3862:61: error: ‘vmx’ undeclared (first use in this function)
> > 3862 | return nested_vmx_preemption_timer_pending(vcpu) || vmx->nested.mtf_pending;
> > | ^~~
> > arch/x86/kvm/vmx/nested.c:3862:61: note: each undeclared identifier is reported only once for each function it appears in
> > CC [M] arch/x86/kvm/svm/svm_onhyperv.o
> > arch/x86/kvm/vmx/nested.c:3863:1: error: control reaches end of non-void function [-Werror=return-type]
> > 3863 | }
> > | ^
> > cc1: all warnings being treated as errors
> > LD [M] arch/x86/kvm/kvm.o
>
> Yeah, it doesn't. Of course this will need a v2, also because there are
> failures in the vmx tests.
Heh, I suspected there would be failures, I was about to type up a response to
patch 3. MTF is subtly relying on the call from kvm_vcpu_running() to inject
the event.
From: Sean Christopherson <seanjc@xxxxxxxxxx>
Date: Fri, 29 Apr 2022 17:30:54 +0000
Subject: [PATCH] KVM: nVMX: Make an event request when pending an MTF nested
VM-Exit
Set KVM_REQ_EVENT when MTF becomes pending to ensure that KVM will run
through inject_pending_event() and thus vmx_check_nested_events() prior
to re-entering the guest. MTF currently works by virtue of KVM's hack
that calls kvm_check_nested_events() from kvm_vcpu_running(), but that
hack will be removed in the near future.
Fixes: 5ef8acbdd687 ("KVM: nVMX: Emulate MTF when performing instruction emulation")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/vmx/vmx.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index d58b763df855..4c635bc08105 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -1577,10 +1577,12 @@ static void vmx_update_emulated_instruction(struct kvm_vcpu *vcpu)
*/
if (nested_cpu_has_mtf(vmcs12) &&
(!vcpu->arch.exception.pending ||
- vcpu->arch.exception.nr == DB_VECTOR))
+ vcpu->arch.exception.nr == DB_VECTOR)) {
vmx->nested.mtf_pending = true;
- else
+ kvm_make_request(KVM_REQ_EVENT, vcpu);
+ } else {
vmx->nested.mtf_pending = false;
+ }
}
static int vmx_skip_emulated_instruction(struct kvm_vcpu *vcpu)
base-commit: 39aa5903e8c407e5128c15aeabb0717b275b007e
--
