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From: Paolo Bonzini <pbonzini@redhat.com>
To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: bdas@redhat.com, dmatlack@google.com
Subject: [PATCH 2/6] KVM: VMX: cleanup check for invalid EPT violation
Date: Wed,  8 Mar 2017 19:03:52 +0100	[thread overview]
Message-ID: <1488996236-5676-3-git-send-email-pbonzini@redhat.com> (raw)
In-Reply-To: <1488996236-5676-1-git-send-email-pbonzini@redhat.com>

handle_ept_violation is checking for "guest-linear-address invalid" +
"paging-structure walk", which is a sign of a bug in KVM.  However,
_all_ EPT violations without a valid guest linear address are paging
structure walks, because those EPT violations happen when loading the
guest PDPTEs.  So simplify the check to only look at bit 7 of the
exit qualification.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/kvm/vmx.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 89b74d9bc357..cb9034601c7b 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -6232,12 +6232,10 @@ static int handle_ept_violation(struct kvm_vcpu *vcpu)
 	unsigned long exit_qualification;
 	gpa_t gpa;
 	u32 error_code;
-	int gla_validity;
 
 	exit_qualification = vmcs_readl(EXIT_QUALIFICATION);
 
-	gla_validity = (exit_qualification >> 7) & 0x3;
-	if (gla_validity == 0x2) {
+	if ((exit_qualification & 0x80) == 0) {
 		printk(KERN_ERR "EPT: Handling EPT violation failed!\n");
 		printk(KERN_ERR "EPT: GPA: 0x%lx, GVA: 0x%lx\n",
 			(long unsigned int)vmcs_read64(GUEST_PHYSICAL_ADDRESS),
-- 
1.8.3.1

  parent reply	other threads:[~2017-03-08 18:33 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-03-08 18:03 [PATCH 0/6] KVM: nVMX: nested EPT improvements and A/D bits, RDRAND and RDSEED exits Paolo Bonzini
2017-03-08 18:03 ` [PATCH 1/6] KVM: nVMX: we support 1GB EPT pages Paolo Bonzini
2017-03-09 10:34   ` David Hildenbrand
2017-03-08 18:03 ` Paolo Bonzini [this message]
2017-03-09 10:43   ` [PATCH 2/6] KVM: VMX: cleanup check for invalid EPT violation David Hildenbrand
2017-03-09 10:50     ` David Hildenbrand
2017-03-28 10:09       ` Paolo Bonzini
2017-03-08 18:03 ` [PATCH 3/6] kvm: x86: MMU support for EPT accessed/dirty bits Paolo Bonzini
2017-03-08 18:03 ` [PATCH 4/6] kvm: nVMX: support " Paolo Bonzini
2017-03-08 18:03 ` [PATCH 5/6] KVM: VMX: add missing exit reasons Paolo Bonzini
2017-03-09  9:27   ` David Hildenbrand
2017-03-08 18:03 ` [PATCH 6/6] KVM: nVMX: support RDRAND and RDSEED exiting Paolo Bonzini
2017-03-13 18:27   ` Jim Mattson
2017-03-14  9:55     ` Paolo Bonzini

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