From: Takuya Yoshikawa <yoshikawa.takuya@xxxxxxxxxxxxx>
This patch injects page fault when reading descriptor in
load_guest_segment_descriptor() fails with FAULT.
Effects of this injection: This function is used by
kvm_load_segment_descriptor() which is necessary for the
following instructions.
- mov seg,r/m16
- jmp far
- pop ?s
This patch makes it possible to emulate the page faults
generated by these instructions. But be sure that unless
we change the kvm_load_segment_descriptor()'s ret value
propagation this patch has no effect.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@xxxxxxxxxxxxx>
Signed-off-by: Gleb Natapov <gleb@xxxxxxxxxx>
---
arch/x86/kvm/x86.c | 13 ++++++++++---
1 files changed, 10 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index b2335f6..0273980 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4713,6 +4713,9 @@ static int load_guest_segment_descriptor(struct kvm_vcpu *vcpu, u16 selector,
{
struct desc_ptr dtable;
u16 index = selector >> 3;
+ int ret;
+ u32 err;
+ gva_t addr;
get_segment_descriptor_dtable(vcpu, selector, &dtable);
@@ -4720,9 +4723,13 @@ static int load_guest_segment_descriptor(struct kvm_vcpu *vcpu, u16 selector,
kvm_queue_exception_e(vcpu, GP_VECTOR, selector & 0xfffc);
return X86EMUL_PROPAGATE_FAULT;
}
- return kvm_read_guest_virt_system(dtable.address + index*8,
- seg_desc, sizeof(*seg_desc),
- vcpu, NULL);
+ addr = dtable.address + index * 8;
+ ret = kvm_read_guest_virt_system(addr, seg_desc, sizeof(*seg_desc),
+ vcpu, &err);
+ if (ret == X86EMUL_PROPAGATE_FAULT)
+ kvm_inject_page_fault(vcpu, addr, err);
+
+ return ret;
}
/* allowed just for 8 bytes segments */
--
1.6.5
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
