KVM: x86: Fix TSS size check for 16-bit tasks

A 16-bit TSS is only 44 bytes long. So make sure to test for the correct
size on task switch.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Jan Kiszka 2010-04-14 16:57:11 +02:00 committed by Avi Kivity
parent eda2beda83
commit e8861cfe2c
1 changed files with 5 additions and 1 deletions

View File

@ -5126,6 +5126,7 @@ int kvm_task_switch(struct kvm_vcpu *vcpu, u16 tss_selector, int reason)
int ret = 0;
u32 old_tss_base = get_segment_base(vcpu, VCPU_SREG_TR);
u16 old_tss_sel = get_segment_selector(vcpu, VCPU_SREG_TR);
u32 desc_limit;
old_tss_base = kvm_mmu_gva_to_gpa_write(vcpu, old_tss_base, NULL);
@ -5148,7 +5149,10 @@ int kvm_task_switch(struct kvm_vcpu *vcpu, u16 tss_selector, int reason)
}
}
if (!nseg_desc.p || get_desc_limit(&nseg_desc) < 0x67) {
desc_limit = get_desc_limit(&nseg_desc);
if (!nseg_desc.p ||
((desc_limit < 0x67 && (nseg_desc.type & 8)) ||
desc_limit < 0x2b)) {
kvm_queue_exception_e(vcpu, TS_VECTOR, tss_selector & 0xfffc);
return 1;
}