On Mon, Feb 22, 2010 at 04:23:32PM +0200, Avi Kivity wrote: > On 02/22/2010 03:59 PM, Marcelo Tosatti wrote: > >Cc: "Michael S. Tsirkin"<m...@redhat.com> > >Signed-off-by: Marcelo Tosatti<mtosa...@redhat.com> > > > >Index: qemu/kvm-all.c > >=================================================================== > >--- qemu.orig/kvm-all.c > >+++ qemu/kvm-all.c > >@@ -718,6 +718,9 @@ static int kvm_handle_io(uint16_t port, > > return 1; > > } > > > >+/* FIXME: arch dependant, x86 version */ > >+#define smp_wmb() asm volatile("" ::: "memory") > >+ > > sfence?
There is no need (for this case). Older read cannot be reordered with write, writes are not reordered with other writes, writes by a single processor are observed in the same order by all processors. > what about other arches? They need to be fixed? PPC needs an instruction apparently. Is there any objection to including this patch?