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author | Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> | 2010-02-01 22:11:04 +0900 |
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committer | Marcelo Tosatti <mtosatti@redhat.com> | 2010-03-01 12:36:07 -0300 |
commit | c125c607326928001983f51109c3d0c190f0a8bb (patch) | |
tree | a5244acb02e408dce30030ce51048a1ce1999a05 /arch | |
parent | ab9f4ecbb6d39a18e300a0d10a4968c37404aa76 (diff) | |
download | linux-stable-c125c607326928001983f51109c3d0c190f0a8bb.tar.gz linux-stable-c125c607326928001983f51109c3d0c190f0a8bb.tar.bz2 linux-stable-c125c607326928001983f51109c3d0c190f0a8bb.zip |
KVM: fix load_guest_segment_descriptor() to return X86EMUL_*
This patch fixes load_guest_segment_descriptor() to return
X86EMUL_PROPAGATE_FAULT when it tries to access the descriptor
table beyond the limit of it: suggested by Marcelo.
I have checked current callers of this helper function,
- kvm_load_segment_descriptor()
- kvm_task_switch()
and confirmed that this patch will change nothing in the
upper layers if we do not change the handling of this
return value from load_guest_segment_descriptor().
Next step: Although fixing the kvm_task_switch() to handle the
propagated faults properly seems difficult, and maybe not worth
it because TSS is not used commonly these days, we can fix
kvm_load_segment_descriptor(). By doing so, the injected #GP
becomes possible to be handled by the guest. The only problem
for this is how to differentiate this fault from the page faults
generated by kvm_read_guest_virt(). We may have to split this
function to achive this goal.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/x86/kvm/x86.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 0bf3df527afc..01f0b037092e 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4663,7 +4663,7 @@ static int load_guest_segment_descriptor(struct kvm_vcpu *vcpu, u16 selector, if (dtable.limit < index * 8 + 7) { kvm_queue_exception_e(vcpu, GP_VECTOR, selector & 0xfffc); - return 1; + return X86EMUL_PROPAGATE_FAULT; } return kvm_read_guest_virt(dtable.base + index*8, seg_desc, sizeof(*seg_desc), vcpu); } |