| Message ID | 1488996236-5676-3-git-send-email-pbonzini@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Am 08.03.2017 um 19:03 schrieb Paolo Bonzini: > 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. Do we have any define for this magic bit 7? #EPT_EXITQ_GLA_VALID 0x80 > > 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), >
Am 09.03.2017 um 11:43 schrieb David Hildenbrand: > Am 08.03.2017 um 19:03 schrieb Paolo Bonzini: >> 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. > > Do we have any define for this magic bit 7? > > #EPT_EXITQ_GLA_VALID 0x80 > Introducing #define EPT_VIOLATION_GLA_VALID_BIT #define EPT_VIOLATION_GLA_VALID would make sense.
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),
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(-)