Re: [PATCH 4/5] KVM: Fix compound mmio.

[Gleb Natapov <gleb@redhat.com>]

On Tue, Apr 12, 2011 at 03:19:00PM +0300, Avi Kivity wrote:
> On 04/12/2011 12:36 PM, Gleb Natapov wrote:
> >mmio_index should be taken into account when copying data from
> >userspace.
> >
> >Signed-off-by: Gleb Natapov<gleb@redhat.com>
> >---
> >  arch/x86/kvm/x86.c |    3 ++-
> >  1 files changed, 2 insertions(+), 1 deletions(-)
> >
> >diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> >index b568779..609c7ab 100644
> >--- a/arch/x86/kvm/x86.c
> >+++ b/arch/x86/kvm/x86.c
> >@@ -5518,7 +5518,8 @@ static int complete_mmio(struct kvm_vcpu *vcpu)
> >  	if (vcpu->mmio_needed) {
> >  		vcpu->mmio_needed = 0;
> >  		if (!vcpu->mmio_is_write)
> >-			memcpy(vcpu->mmio_data, run->mmio.data, 8);
> >+			memcpy(vcpu->mmio_data + vcpu->mmio_index,
> >+			       run->mmio.data, 8);
> >  		vcpu->mmio_index += 8;
> >  		if (vcpu->mmio_index<  vcpu->mmio_size) {
> >  			run->exit_reason = KVM_EXIT_MMIO;
> 
> Interesting, the code passed the emulator.flat sse test.  Does it now?
> 
It pass now and before. Probably by chance. But if I change read_emulated() to do

 int n = min(size, (unsigned)KVM_MMIO_SIZE);

instead of

 int n = min(size, 8u);

emulator.flat fails to emulate far jump instruction.

--
			Gleb.