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path: root/drivers/kvm/x86_emulate.c
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Diffstat (limited to 'drivers/kvm/x86_emulate.c')
-rw-r--r--drivers/kvm/x86_emulate.c51
1 files changed, 12 insertions, 39 deletions
diff --git a/drivers/kvm/x86_emulate.c b/drivers/kvm/x86_emulate.c
index 7513cddb929..7ade09086aa 100644
--- a/drivers/kvm/x86_emulate.c
+++ b/drivers/kvm/x86_emulate.c
@@ -833,8 +833,9 @@ done_prefixes:
dst.ptr = (unsigned long *)cr2;
dst.bytes = (d & ByteOp) ? 1 : op_bytes;
if (d & BitOp) {
- dst.ptr += src.val / BITS_PER_LONG;
- dst.bytes = sizeof(long);
+ unsigned long mask = ~(dst.bytes * 8 - 1);
+
+ dst.ptr = (void *)dst.ptr + (src.val & mask) / 8;
}
if (!(d & Mov) && /* optimisation - avoid slow emulated read */
((rc = ops->read_emulated((unsigned long)dst.ptr,
@@ -1044,7 +1045,7 @@ done_prefixes:
if ((rc = ops->write_std(
register_address(ctxt->ss_base,
_regs[VCPU_REGS_RSP]),
- dst.val, dst.bytes, ctxt)) != 0)
+ &dst.val, dst.bytes, ctxt)) != 0)
goto done;
dst.val = dst.orig_val; /* skanky: disable writeback */
break;
@@ -1077,12 +1078,12 @@ writeback:
case OP_MEM:
if (lock_prefix)
rc = ops->cmpxchg_emulated((unsigned long)dst.
- ptr, dst.orig_val,
- dst.val, dst.bytes,
+ ptr, &dst.orig_val,
+ &dst.val, dst.bytes,
ctxt);
else
rc = ops->write_emulated((unsigned long)dst.ptr,
- dst.val, dst.bytes,
+ &dst.val, dst.bytes,
ctxt);
if (rc != 0)
goto done;
@@ -1320,36 +1321,8 @@ twobyte_special_insn:
realmode_set_cr(ctxt->vcpu, modrm_reg, modrm_val, &_eflags);
break;
case 0xc7: /* Grp9 (cmpxchg8b) */
-#if defined(__i386__)
- {
- unsigned long old_lo, old_hi;
- if (((rc = ops->read_emulated(cr2 + 0, &old_lo, 4,
- ctxt)) != 0)
- || ((rc = ops->read_emulated(cr2 + 4, &old_hi, 4,
- ctxt)) != 0))
- goto done;
- if ((old_lo != _regs[VCPU_REGS_RAX])
- || (old_hi != _regs[VCPU_REGS_RDX])) {
- _regs[VCPU_REGS_RAX] = old_lo;
- _regs[VCPU_REGS_RDX] = old_hi;
- _eflags &= ~EFLG_ZF;
- } else if (ops->cmpxchg8b_emulated == NULL) {
- rc = X86EMUL_UNHANDLEABLE;
- goto done;
- } else {
- if ((rc = ops->cmpxchg8b_emulated(cr2, old_lo,
- old_hi,
- _regs[VCPU_REGS_RBX],
- _regs[VCPU_REGS_RCX],
- ctxt)) != 0)
- goto done;
- _eflags |= EFLG_ZF;
- }
- break;
- }
-#elif defined(CONFIG_X86_64)
{
- unsigned long old, new;
+ u64 old, new;
if ((rc = ops->read_emulated(cr2, &old, 8, ctxt)) != 0)
goto done;
if (((u32) (old >> 0) != (u32) _regs[VCPU_REGS_RAX]) ||
@@ -1358,15 +1331,15 @@ twobyte_special_insn:
_regs[VCPU_REGS_RDX] = (u32) (old >> 32);
_eflags &= ~EFLG_ZF;
} else {
- new = (_regs[VCPU_REGS_RCX] << 32) | (u32) _regs[VCPU_REGS_RBX];
- if ((rc = ops->cmpxchg_emulated(cr2, old,
- new, 8, ctxt)) != 0)
+ new = ((u64)_regs[VCPU_REGS_RCX] << 32)
+ | (u32) _regs[VCPU_REGS_RBX];
+ if ((rc = ops->cmpxchg_emulated(cr2, &old,
+ &new, 8, ctxt)) != 0)
goto done;
_eflags |= EFLG_ZF;
}
break;
}
-#endif
}
goto writeback;