KVM: Cleanup string I/O instruction emulation
Both vmx and svm decode the I/O instructions, and both botch the job,
requiring the instruction prefixes to be fetched in order to completely
decode the instruction.
So, if we see a string I/O instruction, use the x86 emulator to decode it,
as it already has all the prefix decoding machinery.
This patch defines ins/outs opcodes in x86_emulate.c and calls
emulate_instruction() from io_interception() (svm.c) and from handle_io()
(vmx.c). It removes all vmx/svm prefix instruction decoders
(get_addr_size(), io_get_override(), io_address(), get_io_count())
Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 62adaee..661d065 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -1221,7 +1221,10 @@
emulate_ctxt.fs_base = get_segment_base(vcpu, VCPU_SREG_FS);
vcpu->mmio_is_write = 0;
+ vcpu->pio.string = 0;
r = x86_emulate_memop(&emulate_ctxt, &emulate_ops);
+ if (vcpu->pio.string)
+ return EMULATE_DO_MMIO;
if ((r || vcpu->mmio_is_write) && run) {
run->exit_reason = KVM_EXIT_MMIO;