KVM: x86: Loading segments on 64-bit mode may be wrong

The current emulator implementation ignores the high 32 bits of the base in
long-mode.  During segment load from the LDT, the base of the LDT is calculated
incorrectly and may cause the wrong segment to be loaded.

Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Nadav Amit 2014-06-02 18:34:05 +03:00 committed by Paolo Bonzini
parent e37a75a13c
commit 2eedcac8a9
1 changed files with 4 additions and 2 deletions

View File

@ -1358,17 +1358,19 @@ static void get_descriptor_table_ptr(struct x86_emulate_ctxt *ctxt,
u16 selector, struct desc_ptr *dt)
{
const struct x86_emulate_ops *ops = ctxt->ops;
u32 base3 = 0;
if (selector & 1 << 2) {
struct desc_struct desc;
u16 sel;
memset (dt, 0, sizeof *dt);
if (!ops->get_segment(ctxt, &sel, &desc, NULL, VCPU_SREG_LDTR))
if (!ops->get_segment(ctxt, &sel, &desc, &base3,
VCPU_SREG_LDTR))
return;
dt->size = desc_limit_scaled(&desc); /* what if limit > 65535? */
dt->address = get_desc_base(&desc);
dt->address = get_desc_base(&desc) | ((u64)base3 << 32);
} else
ops->get_gdt(ctxt, dt);
}