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KVM: SVM: ignore type when setting segment registers 

Commit 19bca6ab75 ("KVM: SVM: Fix cross vendor migration issue with
unusable bit") added checking type when setting unusable.
So unusable can be set if present is 0 OR type is 0.
According to the AMD processor manual, long mode ignores the type value
in segment descriptor. And type can be 0 if it is read-only data segment.
Therefore type value is not related to unusable flag.

This patch is based on linux-next v4.12.0-rc3.

Signed-off-by: Gioh Kim <gi-oh.kim@profitbricks.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
hifive-unleashed-5.1
Gioh Kim 2017-05-30 15:24:45 +02:00 committed by Paolo Bonzini
parent cbf712792b
commit 8eae9570d1
1 changed files with 1 additions and 1 deletions
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2
arch/x86/kvm/svm.c
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@ -1807,7 +1807,7 @@ static void svm_get_segment(struct kvm_vcpu *vcpu,
* AMD's VMCB does not have an explicit unusable field, so emulate it
* for cross vendor migration purposes by "not present"
*/
var->unusable = !var->present || (var->type == 0);
var->unusable = !var->present;
switch (seg) {
case VCPU_SREG_TR: