Re: [Xen-devel] [PATCH v3 2/2] ioreq-server: write protected range and forwarding

["Ye, Wei" <wei.ye@xxxxxxxxx>]

> -----Original Message-----
> From: xen-devel-bounces@xxxxxxxxxxxxx [mailto:xen-devel-
> bounces@xxxxxxxxxxxxx] On Behalf Of Jan Beulich
> Sent: Wednesday, September 3, 2014 9:17 PM
> To: Ye, Wei
> Cc: Tian, Kevin; keir@xxxxxxx; ian.campbell@xxxxxxxxxx;
> stefano.stabellini@xxxxxxxxxxxxx; tim@xxxxxxx; ian.jackson@xxxxxxxxxxxxx;
> Dugger, Donald D; xen-devel@xxxxxxxxxxxxx; Paul.Durrant@xxxxxxxxxx; Lv,
> Zhiyuan; Zhang, Yang Z
> Subject: Re: [Xen-devel] [PATCH v3 2/2] ioreq-server: write protected range
> and forwarding
> 
> >>> On 03.09.14 at 23:53, <wei.ye@xxxxxxxxx> wrote:
> > +static int hvm_change_p2m_type_ioreq_server(struct domain *d,
> uint16_t set,
> > +                                            uint64_t start, uint64_t
> > +end) {
> > +    int rc = -EINVAL;
> > +    uint64_t gpfn_s, gpfn_e, gpfn;
> > +    p2m_type_t ot, nt;
> > +
> > +    if ( set )
> > +    {
> > +        ot = p2m_ram_rw;
> > +        nt = p2m_mmio_write_dm;
> > +    }
> > +    else
> > +    {
> > +        ot = p2m_mmio_write_dm;
> > +        nt = p2m_ram_rw;
> > +    }
> > +
> > +    gpfn_s = start >> PAGE_SHIFT;
> > +    gpfn_e = end >> PAGE_SHIFT;
> 
> Considering that the first really ought to be PFN_DOWN() - is the latter 
> really
> correct? I'd rather expect that to be PFN_UP()...
> 
I think the latter one is also should be PFN_DOWN. Considering a range is 
[0x0000, 0x1000],
then only the first pfn 0 should be changed. Note that the follow loop:
for (gpfn = gpfn_s; gpfn <= gpfn_e; gpfn++)
The gpfn_e is included. If PFN_UP is to calculate the gpfn_e, there's wrong p2m 
type change
to pfn 1.

Wei
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxx
> http://lists.xen.org/xen-devel

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel