[PATCH v2 4/5] KVM: MMU: fix apf prefault if nested guest is enabled

[Xiao Guangrong]

If apf is generated in L2 guest and is completed in L1 guest, it will
prefault this apf in L1 guest's mmu context.

Signed-off-by: Xiao Guangrong <xiaoguangrong@xxxxxxxxxxxxxx>
---
 arch/x86/include/asm/kvm_host.h |    1 +
 arch/x86/kvm/mmu.c              |    1 +
 arch/x86/kvm/x86.c              |    3 ++-
 3 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 7f20f2c..b04c0fa 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -600,6 +600,7 @@ struct kvm_x86_ops {
 struct kvm_arch_async_pf {
 	u32 token;
 	gfn_t gfn;
+	bool direct_map;
 };
 
 extern struct kvm_x86_ops *kvm_x86_ops;
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 5ee5b97..bdb9fa9 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2608,6 +2608,7 @@ static int kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu, gva_t gva, gfn_t gfn)
 	struct kvm_arch_async_pf arch;
 	arch.token = (vcpu->arch.apf.id++ << 12) | vcpu->vcpu_id;
 	arch.gfn = gfn;
+	arch.direct_map = vcpu->arch.mmu.direct_map;
 
 	return kvm_setup_async_pf(vcpu, gva, gfn, &arch);
 }
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index c071d73..003a0ca 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6169,7 +6169,8 @@ void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf *work)
 {
 	int r;
 
-	if (!vcpu->arch.mmu.direct_map || is_error_page(work->page))
+	if (!vcpu->arch.mmu.direct_map || !work->arch.direct_map ||
+	      is_error_page(work->page))
 		return;
 
 	r = kvm_mmu_reload(vcpu);
-- 
1.7.0.4

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