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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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