Gitweb: http://git.kernel.org/linus/c125c607326928001983f51109c3d0c190f0a8bb
Commit: c125c607326928001983f51109c3d0c190f0a8bb
Parent: ab9f4ecbb6d39a18e300a0d10a4968c37404aa76
Author: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
AuthorDate: Mon Feb 1 22:11:04 2010 +0900
Committer: Marcelo Tosatti <mtosatti@redhat.com>
CommitDate: Mon Mar 1 12:36:07 2010 -0300
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>
---
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 0bf3df5..01f0b03 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);
}
--
To unsubscribe from this list: send the line "unsubscribe git-commits-head" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
