On 08/01/2010 11:28 AM, Gleb Natapov wrote:
On Sat, Jul 31, 2010 at 08:25:13PM +0300, Avi Kivity wrote:
  On 07/29/2010 03:11 PM, Gleb Natapov wrote:
No need to update vcpu state since instruction is in the middle of the
emulation.

Signed-off-by: Gleb Natapov<[email protected]>
---
  arch/x86/kvm/x86.c |   31 +++++++++++++------------------
  1 files changed, 13 insertions(+), 18 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 76fbc32..7e5f075 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4057,32 +4057,27 @@ restart:
                return handle_emulation_failure(vcpu);
        }

-       toggle_interruptibility(vcpu, vcpu->arch.emulate_ctxt.interruptibility);
-       kvm_x86_ops->set_rflags(vcpu, vcpu->arch.emulate_ctxt.eflags);
-       memcpy(vcpu->arch.regs, c->regs, sizeof c->regs);
-       kvm_rip_write(vcpu, vcpu->arch.emulate_ctxt.eip);
+       r = EMULATE_DONE;

-       if (vcpu->arch.emulate_ctxt.exception>= 0) {
+       if (vcpu->arch.emulate_ctxt.exception>= 0)
                inject_emulated_exception(vcpu);
-               return EMULATE_DONE;
-       }
-
-       if (vcpu->arch.pio.count) {
+       else if (vcpu->arch.pio.count) {
                if (!vcpu->arch.pio.in)
                        vcpu->arch.pio.count = 0;
-               return EMULATE_DO_MMIO;
-       }
-
-       if (vcpu->mmio_needed) {
+               r = EMULATE_DO_MMIO;
+       } else if (vcpu->mmio_needed) {
                if (vcpu->mmio_is_write)
                        vcpu->mmio_needed = 0;
-               return EMULATE_DO_MMIO;
-       }
-
-       if (vcpu->arch.emulate_ctxt.restart)
+               r = EMULATE_DO_MMIO;
+       } else if (vcpu->arch.emulate_ctxt.restart)
                goto restart;

-       return EMULATE_DONE;
+       toggle_interruptibility(vcpu, vcpu->arch.emulate_ctxt.interruptibility);
+       kvm_x86_ops->set_rflags(vcpu, vcpu->arch.emulate_ctxt.eflags);
+       memcpy(vcpu->arch.regs, c->regs, sizeof c->regs);
+       kvm_rip_write(vcpu, vcpu->arch.emulate_ctxt.eip);
+
+       return r;
  }
  EXPORT_SYMBOL_GPL(emulate_instruction);

What about kvm-tpr-opt.c?  It uses rip after pio.

It uses rip _during_ pio. And pio emulation changes rip
only at the end of emulation.

But non-emulated pio does a skip_emulated_instruction() immediately (or so the code in kvm-tpr-opt.c assumes:

static void vtpr_ioport_write(void *opaque, uint32_t addr, uint32_t val)
{
    CPUState *env = cpu_single_env;
    uint32_t rip;

    cpu_synchronize_state(env);

    rip = env->eip - 2;
    write_byte_virt(env, rip, 0x66);
    write_byte_virt(env, rip + 1, 0x90);

)

--
error compiling committee.c: too many arguments to function

--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to