linux-kernel - [PATCH 7/9] KVM: VMX: Don't kill the VM on an unexpected #VE

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Date: Fri, 17 May 2024 17:04:28 -0700
From: Sean Christopherson <seanjc@...gle.com>
To: Sean Christopherson <seanjc@...gle.com>, Paolo Bonzini <pbonzini@...hat.com>
Cc: kvm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH 7/9] KVM: VMX: Don't kill the VM on an unexpected #VE

Don't terminiate the VM on an unexpected #VE, as it's extremely unlikely
the #VE is fatal to the guest, and even less likely that it presents a
danger to the host.  Simply resume the guest on "failure", as the #VE info
page's BUSY field will prevent converting any more EPT Violations to #VEs
for the vCPU (at least, that's what the BUSY field is supposed to do).

Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 arch/x86/kvm/vmx/vmx.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 2a3fce61c785..58832aae2248 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -5217,14 +5217,14 @@ static int handle_exception_nmi(struct kvm_vcpu *vcpu)
 	if (is_invalid_opcode(intr_info))
 		return handle_ud(vcpu);
 
-	if (KVM_BUG_ON(is_ve_fault(intr_info), vcpu->kvm)) {
+	if (WARN_ON_ONCE(is_ve_fault(intr_info))) {
 		struct vmx_ve_information *ve_info = vmx->ve_info;
 
 		WARN_ONCE(ve_info->exit_reason != EXIT_REASON_EPT_VIOLATION,
 			  "Unexpected #VE on VM-Exit reason 0x%x", ve_info->exit_reason);
 		dump_vmcs(vcpu);
 		kvm_mmu_print_sptes(vcpu, ve_info->guest_physical_address, "#VE");
-		return -EIO;
+		return 1;
 	}
 
 	error_code = 0;
-- 
2.45.0.215.g3402c0e53f-goog