Patchwork [V2,1/2] KVM/VMX: Check ept_pointer before flushing ept tlb

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Submitter 蓝天宇
Date Dec. 6, 2018, 7:34 a.m.
Message ID <20181206073437.1995-1-Tianyu.Lan@microsoft.com>
Download mbox | patch
Permalink /patch/673835/
State New
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Comments

蓝天宇 - Dec. 6, 2018, 7:34 a.m.
From: Lan Tianyu <Tianyu.Lan@microsoft.com>

This patch is to initialize ept_pointer to INVALID_PAGE and check it
before flushing ept tlb. If ept_pointer is invalid, bypass the flush
request.

Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com>
---
 arch/x86/kvm/vmx.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

Patch

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index c379d0bfdcba..6577ec8cbb0f 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -1582,11 +1582,18 @@  static int vmx_hv_remote_flush_tlb(struct kvm *kvm)
 	/*
 	 * FLUSH_GUEST_PHYSICAL_ADDRESS_SPACE hypercall needs the address of the
 	 * base of EPT PML4 table, strip off EPT configuration information.
+	 * If ept_pointer is invalid pointer, bypass the flush request.
 	 */
 	if (to_kvm_vmx(kvm)->ept_pointers_match != EPT_POINTERS_MATCH) {
-		kvm_for_each_vcpu(i, vcpu, kvm)
+		kvm_for_each_vcpu(i, vcpu, kvm) {
+			u64 ept_pointer = to_vmx(vcpu)->ept_pointer;
+
+			if (!VALID_PAGE(ept_pointer))
+				continue;
+
 			ret |= hyperv_flush_guest_mapping(
-				to_vmx(kvm_get_vcpu(kvm, i))->ept_pointer & PAGE_MASK);
+				ept_pointer & PAGE_MASK);
+		}
 	} else {
 		ret = hyperv_flush_guest_mapping(
 				to_vmx(kvm_get_vcpu(kvm, 0))->ept_pointer & PAGE_MASK);
@@ -11614,6 +11621,8 @@  static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id)
 	vmx->pi_desc.nv = POSTED_INTR_VECTOR;
 	vmx->pi_desc.sn = 1;
 
+	vmx->ept_pointer = INVALID_PAGE;
+
 	return &vmx->vcpu;
 
 free_vmcs: