linux-kernel - [PATCH] KVM: nVMX: Fix windows guest BSOD due to fail Intel FlexPriority

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Date:   Fri,  4 Aug 2017 15:38:07 -0700
From:   Wanpeng Li <kernellwp@...il.com>
To:     linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc:     Paolo Bonzini <pbonzini@...hat.com>,
        Radim Krčmář <rkrcmar@...hat.com>,
        Wanpeng Li <wanpeng.li@...mail.com>
Subject: [PATCH] KVM: nVMX: Fix windows guest BSOD due to fail Intel FlexPriority

From: Wanpeng Li <wanpeng.li@...mail.com>

Intel FlexPriority maintains a "virtual TPR" register in memory(Virtual 
APIC Page), APIC-access Page contains host physical address of guest APIC 
page, Virtual APIC Page contains host physical address of the page stored 
LAPIC registers. However, commit dc651f440f5 (KVM: nVMX: get rid of 
nested_get_page()) sets the address of APIC-access Page to the vmcs field 
of Virtual APIC Page which breaks the FlexPriority.

This patch fixes it by setting Virtual APIC Page to it related vmcs field.

Cc: Paolo Bonzini <pbonzini@...hat.com>
Cc: Radim Krčmář <rkrcmar@...hat.com>
Signed-off-by: Wanpeng Li <wanpeng.li@...mail.com>
---
 arch/x86/kvm/vmx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index b22af24..a653005 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -9654,7 +9654,7 @@ static void nested_get_vmcs12_pages(struct kvm_vcpu *vcpu,
 			kvm_release_page_dirty(vmx->nested.virtual_apic_page);
 			vmx->nested.virtual_apic_page = NULL;
 		}
-		page = kvm_vcpu_gpa_to_page(vcpu, vmcs12->apic_access_addr);
+		page = kvm_vcpu_gpa_to_page(vcpu, vmcs12->virtual_apic_page_addr);

 		/*
 		 * If translation failed, VM entry will fail because
-- 
2.7.4