| Message ID | 571F417A02000078000E5A98@prv-mh.provo.novell.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
> -----Original Message----- > From: Jan Beulich [mailto:JBeulich@suse.com] > Sent: 26 April 2016 09:23 > To: xen-devel > Cc: Paul Durrant; Wei Liu > Subject: [PATCH] x86/HVM: correct last address emulation acceptance check > > For REPeated memory access instructions the repeat count also needs to > be considered. Utilize that "last" already takes this into account. > > Also defer computing "last" until we really know we need it. > > Signed-off-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Paul Durrant <paul.durrant@citrix.com> > > --- a/xen/arch/x86/hvm/intercept.c > +++ b/xen/arch/x86/hvm/intercept.c > @@ -34,16 +34,16 @@ > static bool_t hvm_mmio_accept(const struct hvm_io_handler *handler, > const ioreq_t *p) > { > - paddr_t first = hvm_mmio_first_byte(p); > - paddr_t last = hvm_mmio_last_byte(p); > + paddr_t first = hvm_mmio_first_byte(p), last; > > BUG_ON(handler->type != IOREQ_TYPE_COPY); > > if ( !handler->mmio.ops->check(current, first) ) > return 0; > > - /* Make sure the handler will accept the whole access */ > - if ( p->size > 1 && > + /* Make sure the handler will accept the whole access. */ > + last = hvm_mmio_last_byte(p); > + if ( last != first && > !handler->mmio.ops->check(current, last) ) > domain_crash(current->domain); > > >
On Tue, Apr 26, 2016 at 02:22:50AM -0600, Jan Beulich wrote: > For REPeated memory access instructions the repeat count also needs to > be considered. Utilize that "last" already takes this into account. > > Also defer computing "last" until we really know we need it. > > Signed-off-by: Jan Beulich <jbeulich@suse.com> Release-acked-by: Wei Liu <wei.liu2@citrix.com>
--- a/xen/arch/x86/hvm/intercept.c +++ b/xen/arch/x86/hvm/intercept.c @@ -34,16 +34,16 @@ static bool_t hvm_mmio_accept(const struct hvm_io_handler *handler, const ioreq_t *p) { - paddr_t first = hvm_mmio_first_byte(p); - paddr_t last = hvm_mmio_last_byte(p); + paddr_t first = hvm_mmio_first_byte(p), last; BUG_ON(handler->type != IOREQ_TYPE_COPY); if ( !handler->mmio.ops->check(current, first) ) return 0; - /* Make sure the handler will accept the whole access */ - if ( p->size > 1 && + /* Make sure the handler will accept the whole access. */ + last = hvm_mmio_last_byte(p); + if ( last != first && !handler->mmio.ops->check(current, last) ) domain_crash(current->domain);