[PATCH v5 22/27] KVM: x86: Treat pending TRIPLE_FAULT requests as pending exceptions

From: Sean Christopherson
Date: Tue Aug 30 2022 - 19:20:14 EST


Treat pending TRIPLE_FAULTS as pending exceptions. A triple fault is an
exception for all intents and purposes, it's just not tracked as such
because there's no vector associated the exception. E.g. if userspace
were to set vcpu->request_interrupt_window while running L2 and L2 hit a
triple fault, a triple fault nested VM-Exit should be synthesized to L1
before exiting to userspace with KVM_EXIT_IRQ_WINDOW_OPEN.

Link: https://lore.kernel.org/all/YoVHAIGcFgJit1qp@xxxxxxxxxx
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Reviewed-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
---
arch/x86/kvm/x86.c | 3 ---
arch/x86/kvm/x86.h | 3 ++-
2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 17cf43ca42c3..d004e18c7cdb 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -12742,9 +12742,6 @@ static inline bool kvm_vcpu_has_events(struct kvm_vcpu *vcpu)
if (kvm_xen_has_pending_events(vcpu))
return true;

- if (kvm_test_request(KVM_REQ_TRIPLE_FAULT, vcpu))
- return true;
-
return false;
}

diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index 256745d1a2c3..a784ff90740b 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -85,7 +85,8 @@ int kvm_check_nested_events(struct kvm_vcpu *vcpu);
static inline bool kvm_is_exception_pending(struct kvm_vcpu *vcpu)
{
return vcpu->arch.exception.pending ||
- vcpu->arch.exception_vmexit.pending;
+ vcpu->arch.exception_vmexit.pending ||
+ kvm_test_request(KVM_REQ_TRIPLE_FAULT, vcpu);
}

static inline void kvm_clear_exception_queue(struct kvm_vcpu *vcpu)
--
2.37.2.672.g94769d06f0-goog