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| author | Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> | 2010-02-18 11:15:00 +0100 |
|---|---|---|
| committer | Marcelo Tosatti <mtosatti@redhat.com> | 2010-03-01 16:36:13 +0100 |
| commit | 6f550484a15ea1b468665cdf59f020bf08ccb292 (patch) | |
| tree | d4088b1aa157dca4dadc2a99969299dc46098148 /arch | |
| parent | KVM: x86 emulator: Forbid modifying CS segment register by mov instruction (diff) | |
| download | linux-6f550484a15ea1b468665cdf59f020bf08ccb292.tar.xz linux-6f550484a15ea1b468665cdf59f020bf08ccb292.zip | |
KVM: Fix load_guest_segment_descriptor() to inject page fault
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@oss.ntt.co.jp>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | 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 f6ae4875d9d0..203ee7d0ed58 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 descriptor_table 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.base + index*8, - seg_desc, sizeof(*seg_desc), - vcpu, NULL); + addr = dtable.base + 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 */ |