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Subject[PATCH 12/37] KVM: VMX: Fix guest state validity checks
Date
The vmx guest state validity checks are full of bugs.  Make them
conform to the manual.

Signed-off-by: Avi Kivity <avi@redhat.com>
---
arch/x86/kvm/vmx.c | 18 ++++++++++++++----
1 files changed, 14 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 3312047..be94410 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -1784,14 +1784,16 @@ static bool code_segment_valid(struct kvm_vcpu *vcpu)
vmx_get_segment(vcpu, &cs, VCPU_SREG_CS);
cs_rpl = cs.selector & SELECTOR_RPL_MASK;

+ if (cs.unusable)
+ return false;
if (~cs.type & (AR_TYPE_CODE_MASK|AR_TYPE_ACCESSES_MASK))
return false;
if (!cs.s)
return false;
- if (!(~cs.type & (AR_TYPE_CODE_MASK|AR_TYPE_WRITEABLE_MASK))) {
+ if (cs.type & AR_TYPE_WRITEABLE_MASK) {
if (cs.dpl > cs_rpl)
return false;
- } else if (cs.type & AR_TYPE_CODE_MASK) {
+ } else {
if (cs.dpl != cs_rpl)
return false;
}
@@ -1810,7 +1812,9 @@ static bool stack_segment_valid(struct kvm_vcpu *vcpu)
vmx_get_segment(vcpu, &ss, VCPU_SREG_SS);
ss_rpl = ss.selector & SELECTOR_RPL_MASK;

- if ((ss.type != 3) || (ss.type != 7))
+ if (ss.unusable)
+ return true;
+ if (ss.type != 3 && ss.type != 7)
return false;
if (!ss.s)
return false;
@@ -1830,6 +1834,8 @@ static bool data_segment_valid(struct kvm_vcpu *vcpu, int seg)
vmx_get_segment(vcpu, &var, seg);
rpl = var.selector & SELECTOR_RPL_MASK;

+ if (var.unusable)
+ return true;
if (!var.s)
return false;
if (!var.present)
@@ -1851,9 +1857,11 @@ static bool tr_valid(struct kvm_vcpu *vcpu)

vmx_get_segment(vcpu, &tr, VCPU_SREG_TR);

+ if (tr.unusable)
+ return false;
if (tr.selector & SELECTOR_TI_MASK) /* TI = 1 */
return false;
- if ((tr.type != 3) || (tr.type != 11)) /* TODO: Check if guest is in IA32e mode */
+ if (tr.type != 3 && tr.type != 11) /* TODO: Check if guest is in IA32e mode */
return false;
if (!tr.present)
return false;
@@ -1867,6 +1875,8 @@ static bool ldtr_valid(struct kvm_vcpu *vcpu)

vmx_get_segment(vcpu, &ldtr, VCPU_SREG_LDTR);

+ if (ldtr.unusable)
+ return true;
if (ldtr.selector & SELECTOR_TI_MASK) /* TI = 1 */
return false;
if (ldtr.type != 2)
--
1.6.0.6


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