diff options
| author | Avi Kivity <avi@redhat.com> | 2012-08-21 16:07:04 +0200 |
|---|---|---|
| committer | Marcelo Tosatti <mtosatti@redhat.com> | 2012-08-28 01:02:20 +0200 |
| commit | 03ebebeb1ff5d1d6209fd8df4ffc9204df82bd55 (patch) | |
| tree | 47af40344c5f609e34acbc9136fe5c04b2893282 | |
| parent | KVM: VMX: Allow vm86 virtualization of big real mode (diff) | |
| download | linux-03ebebeb1ff5d1d6209fd8df4ffc9204df82bd55.tar.xz linux-03ebebeb1ff5d1d6209fd8df4ffc9204df82bd55.zip | |
KVM: x86 emulator: Leave segment limit and attributs alone in real mode
When loading a segment in real mode, only the base and selector must
be modified. The limit needs to be left alone, otherwise big real mode
users will hit a #GP due to limit checking (currently this is suppressed
because we don't check limits in real mode).
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
| -rw-r--r-- | arch/x86/kvm/emulate.c | 8 |
1 files changed, 2 insertions, 6 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 5e27ba532613..f8b27cd2a6cb 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -1388,19 +1388,15 @@ static int load_segment_descriptor(struct x86_emulate_ctxt *ctxt, bool null_selector = !(selector & ~0x3); /* 0000-0003 are null */ ulong desc_addr; int ret; + u16 dummy; memset(&seg_desc, 0, sizeof seg_desc); if ((seg <= VCPU_SREG_GS && ctxt->mode == X86EMUL_MODE_VM86) || ctxt->mode == X86EMUL_MODE_REAL) { /* set real mode segment descriptor */ + ctxt->ops->get_segment(ctxt, &dummy, &seg_desc, NULL, seg); set_desc_base(&seg_desc, selector << 4); - set_desc_limit(&seg_desc, 0xffff); - seg_desc.type = 3; - seg_desc.p = 1; - seg_desc.s = 1; - if (ctxt->mode == X86EMUL_MODE_VM86) - seg_desc.dpl = 3; goto load; } |