Re: [PATCH v2 04/20] virtio: Implement get_shm_region for PCI transport

[Vivek Goyal <vgoyal@redhat.com>]

On Thu, Aug 13, 2020 at 07:51:56PM -0700, Gurchetan Singh wrote:
> On Mon, Aug 10, 2020 at 7:50 AM Vivek Goyal <vgoyal@redhat.com> wrote:
> 
> > On Mon, Aug 10, 2020 at 10:05:17AM -0400, Michael S. Tsirkin wrote:
> > > On Fri, Aug 07, 2020 at 03:55:10PM -0400, Vivek Goyal wrote:
> > > > From: Sebastien Boeuf <sebastien.boeuf@intel.com>
> > > >
> > > > On PCI the shm regions are found using capability entries;
> > > > find a region by searching for the capability.
> > > >
> > > > Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
> > > > Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> > > > Signed-off-by: kbuild test robot <lkp@intel.com>
> > > > Cc: kvm@vger.kernel.org
> > > > Cc: "Michael S. Tsirkin" <mst@redhat.com>
> > >
> > > Acked-by: Michael S. Tsirkin <mst@redhat.com>
> > >
> >
> > [..]
> > > > +static bool vp_get_shm_region(struct virtio_device *vdev,
> > > > +                         struct virtio_shm_region *region, u8 id)
> > > > +{
> > > > +   struct virtio_pci_device *vp_dev = to_vp_device(vdev);
> > > > +   struct pci_dev *pci_dev = vp_dev->pci_dev;
> > > > +   u8 bar;
> > > > +   u64 offset, len;
> > > > +   phys_addr_t phys_addr;
> > > > +   size_t bar_len;
> > > > +
> > > > +   if (!virtio_pci_find_shm_cap(pci_dev, id, &bar, &offset, &len)) {
> > > > +           return false;
> > > > +   }
> > > > +
> > > > +   phys_addr = pci_resource_start(pci_dev, bar);
> > > > +   bar_len = pci_resource_len(pci_dev, bar);
> > > > +
> > > > +   if ((offset + len) < offset) {
> > > > +           dev_err(&pci_dev->dev, "%s: cap offset+len overflow
> > detected\n",
> > > > +                   __func__);
> > > > +           return false;
> > > > +   }
> > > > +
> > > > +   if (offset + len > bar_len) {
> > > > +           dev_err(&pci_dev->dev, "%s: bar shorter than cap
> > offset+len\n",
> > > > +                   __func__);
> > > > +           return false;
> > > > +   }
> > >
> > > Maybe move this to a common header so the checks can be reused by
> > > other transports? Can be a patch on top.
> >
> > Will do as patch on top once these patches get merged.
> >
> 
> There's also some minor checkpatch complaints.  I fixed them with the
> series I sent out with virtio-gpu.

Thanks Gurchetan. I will post the patch with V3 posting anyway. We both
need these patches. So whatever gets merged in the tree first, other
person can use it.

Vivek