> -----Original Message-----
> From: Jan Beulich [mailto:jbeul...@suse.com]
> Sent: 25 September 2017 17:00
> To: Paul Durrant <paul.durr...@citrix.com>
> Cc: Andrew Cooper <andrew.coop...@citrix.com>; George Dunlap
> <george.dun...@citrix.com>; Ian Jackson <ian.jack...@citrix.com>;
> Stefano Stabellini <sstabell...@kernel.org>; xen-de...@lists.xenproject.org;
> Konrad Rzeszutek Wilk <konrad.w...@oracle.com>; Tim (Xen.org)
> <t...@xen.org>
> Subject: Re: [PATCH v7 11/12] x86/hvm/ioreq: defer mapping gfns until they
> are actually requsted
>
> >>> On 18.09.17 at 17:31, <paul.durr...@citrix.com> wrote:
> > --- a/xen/arch/x86/hvm/ioreq.c
> > +++ b/xen/arch/x86/hvm/ioreq.c
> > @@ -354,6 +354,9 @@ static void hvm_update_ioreq_evtchn(struct
> hvm_ioreq_server *s,
> > }
> > }
> >
> > +#define HANDLE_BUFIOREQ(s) \
> > + (s->bufioreq_handling != HVM_IOREQSRV_BUFIOREQ_OFF)
>
> (s)
>
> > @@ -762,11 +755,20 @@ int hvm_get_ioreq_server_info(struct domain
> *d, ioservid_t id,
> > if ( IS_DEFAULT(s) )
> > goto out;
> >
> > + if ( ioreq_gfn || bufioreq_gfn )
>
> This conditional together with ...
>
> > + {
> > + rc = hvm_ioreq_server_map_pages(s);
> > + if ( rc )
> > + goto out;
> > + }
> > +
> > *ioreq_gfn = gfn_x(s->ioreq.gfn);
>
> ... this unconditional dereference is suspicious.
True, it should be protected.
>
> > --- a/xen/include/asm-x86/hvm/domain.h
> > +++ b/xen/include/asm-x86/hvm/domain.h
> > @@ -68,8 +68,8 @@ struct hvm_ioreq_server {
> > spinlock_t bufioreq_lock;
> > evtchn_port_t bufioreq_evtchn;
> > struct rangeset *range[NR_IO_RANGE_TYPES];
> > + int bufioreq_handling;
>
> Does this need to be plain int (i.e. signed and 32 bits wide)?
No, I can shrink it.
Paul
>
> Jan
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
https://lists.xen.org/xen-devel
