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author | Paolo Bonzini <pbonzini@redhat.com> | 2014-08-18 13:15:51 +0200 |
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committer | Paolo Bonzini <pbonzini@redhat.com> | 2014-08-19 15:12:28 +0200 |
commit | 9a4cfb27f7233610c5ddc82329c26d39683fad72 (patch) | |
tree | bc07f3fc14295c10037ec7adc6b0444f25515740 /arch | |
parent | KVM: x86: Avoid emulating instructions on #UD mistakenly (diff) | |
download | linux-9a4cfb27f7233610c5ddc82329c26d39683fad72.tar.xz linux-9a4cfb27f7233610c5ddc82329c26d39683fad72.zip |
KVM: x86: do not check CS.DPL against RPL during task switch
This reverts the check added by commit 5045b468037d (KVM: x86: check CS.DPL
against RPL during task switch, 2014-05-15). Although the CS.DPL=CS.RPL
check is mentioned in table 7-1 of the SDM as causing a #TSS exception,
it is not mentioned in table 6-6 that lists "invalid TSS conditions"
which cause #TSS exceptions. In fact it causes some tests to fail, which
pass on bare-metal.
Keep the rest of the commit, since we will find new uses for it in 3.18.
Reported-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/x86/kvm/emulate.c | 3 |
1 files changed, 0 insertions, 3 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index ef117b842334..03954f7900f5 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -1491,9 +1491,6 @@ static int __load_segment_descriptor(struct x86_emulate_ctxt *ctxt, goto exception; break; case VCPU_SREG_CS: - if (in_task_switch && rpl != dpl) - goto exception; - if (!(seg_desc.type & 8)) goto exception; |