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authorAvi Kivity <avi@qumranet.com>2007-01-06 03:36:51 +0300
committerLinus Torvalds <torvalds@woody.osdl.org>2007-01-06 10:55:26 +0300
commit32b35627355c3bf17e1903efd117efed7653a54e (patch)
tree9ef6ca5a32f6e224f4d463a89c21dda2ac08eafe
parent3bb65a22a4502067f8cd3cb4c923ffa70be62091 (diff)
downloadlinux-sunxi-32b35627355c3bf17e1903efd117efed7653a54e.tar.xz
[PATCH] KVM: MMU: Fix cmpxchg8b emulation
cmpxchg8b uses edx:eax as the compare operand, not edi:eax. cmpxchg8b is used by 32-bit pae guests to set page table entries atomically, and this is emulated touching shadowed guest page tables. Also, implement it for 32-bit hosts. Signed-off-by: Avi Kivity <avi@qumranet.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--drivers/kvm/kvm_main.c27
-rw-r--r--drivers/kvm/x86_emulate.c2
2 files changed, 28 insertions, 1 deletions
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index cec10106ce77..2e6bc5659953 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -936,6 +936,30 @@ static int emulator_cmpxchg_emulated(unsigned long addr,
return emulator_write_emulated(addr, new, bytes, ctxt);
}
+#ifdef CONFIG_X86_32
+
+static int emulator_cmpxchg8b_emulated(unsigned long addr,
+ unsigned long old_lo,
+ unsigned long old_hi,
+ unsigned long new_lo,
+ unsigned long new_hi,
+ struct x86_emulate_ctxt *ctxt)
+{
+ static int reported;
+ int r;
+
+ if (!reported) {
+ reported = 1;
+ printk(KERN_WARNING "kvm: emulating exchange8b as write\n");
+ }
+ r = emulator_write_emulated(addr, new_lo, 4, ctxt);
+ if (r != X86EMUL_CONTINUE)
+ return r;
+ return emulator_write_emulated(addr+4, new_hi, 4, ctxt);
+}
+
+#endif
+
static unsigned long get_segment_base(struct kvm_vcpu *vcpu, int seg)
{
return kvm_arch_ops->get_segment_base(vcpu, seg);
@@ -1010,6 +1034,9 @@ struct x86_emulate_ops emulate_ops = {
.read_emulated = emulator_read_emulated,
.write_emulated = emulator_write_emulated,
.cmpxchg_emulated = emulator_cmpxchg_emulated,
+#ifdef CONFIG_X86_32
+ .cmpxchg8b_emulated = emulator_cmpxchg8b_emulated,
+#endif
};
int emulate_instruction(struct kvm_vcpu *vcpu,
diff --git a/drivers/kvm/x86_emulate.c b/drivers/kvm/x86_emulate.c
index 1bff3e925fda..be70795b4822 100644
--- a/drivers/kvm/x86_emulate.c
+++ b/drivers/kvm/x86_emulate.c
@@ -1323,7 +1323,7 @@ twobyte_special_insn:
ctxt)) != 0))
goto done;
if ((old_lo != _regs[VCPU_REGS_RAX])
- || (old_hi != _regs[VCPU_REGS_RDI])) {
+ || (old_hi != _regs[VCPU_REGS_RDX])) {
_regs[VCPU_REGS_RAX] = old_lo;
_regs[VCPU_REGS_RDX] = old_hi;
_eflags &= ~EFLG_ZF;