Re: [PATCH v2 04/20] virtio: Implement get_shm_region for PCI transport
On Thu, Aug 13, 2020 at 07:51:56PM -0700, Gurchetan Singh wrote:
> On Mon, Aug 10, 2020 at 7:50 AM Vivek Goyal 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
> > > >
> > > > On PCI the shm regions are found using capability entries;
> > > > find a region by searching for the capability.
> > > >
> > > > Signed-off-by: Sebastien Boeuf
> > > > Signed-off-by: Dr. David Alan Gilbert
> > > > Signed-off-by: kbuild test robot
> > > > Cc: k...@vger.kernel.org
> > > > Cc: "Michael S. Tsirkin"
> > >
> > > Acked-by: Michael S. Tsirkin
> > >
> >
> > [..]
> > > > +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
Re: [PATCH v2 04/20] virtio: Implement get_shm_region for PCI transport
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
> >
> > On PCI the shm regions are found using capability entries;
> > find a region by searching for the capability.
> >
> > Signed-off-by: Sebastien Boeuf
> > Signed-off-by: Dr. David Alan Gilbert
> > Signed-off-by: kbuild test robot
> > Cc: k...@vger.kernel.org
> > Cc: "Michael S. Tsirkin"
>
> Acked-by: Michael S. Tsirkin
>
[..]
> > +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.
Thanks
Vivek
Re: [PATCH v2 04/20] virtio: Implement get_shm_region for PCI transport
On Fri, Aug 07, 2020 at 03:55:10PM -0400, Vivek Goyal wrote:
> From: Sebastien Boeuf
>
> On PCI the shm regions are found using capability entries;
> find a region by searching for the capability.
>
> Signed-off-by: Sebastien Boeuf
> Signed-off-by: Dr. David Alan Gilbert
> Signed-off-by: kbuild test robot
> Cc: k...@vger.kernel.org
> Cc: "Michael S. Tsirkin"
Acked-by: Michael S. Tsirkin
> ---
> drivers/virtio/virtio_pci_modern.c | 96 ++
> include/uapi/linux/virtio_pci.h| 11 +++-
> 2 files changed, 106 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/virtio/virtio_pci_modern.c
> b/drivers/virtio/virtio_pci_modern.c
> index db93cedd262f..3fc0cd848fe9 100644
> --- a/drivers/virtio/virtio_pci_modern.c
> +++ b/drivers/virtio/virtio_pci_modern.c
> @@ -444,6 +444,100 @@ static void del_vq(struct virtio_pci_vq_info *info)
> vring_del_virtqueue(vq);
> }
>
> +static int virtio_pci_find_shm_cap(struct pci_dev *dev, u8 required_id,
> +u8 *bar, u64 *offset, u64 *len)
> +{
> + int pos;
> +
> + for (pos = pci_find_capability(dev, PCI_CAP_ID_VNDR); pos > 0;
> + pos = pci_find_next_capability(dev, pos, PCI_CAP_ID_VNDR)) {
> + u8 type, cap_len, id;
> + u32 tmp32;
> + u64 res_offset, res_length;
> +
> + pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
> + cfg_type), &type);
> + if (type != VIRTIO_PCI_CAP_SHARED_MEMORY_CFG)
> + continue;
> +
> + pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
> + cap_len), &cap_len);
> + if (cap_len != sizeof(struct virtio_pci_cap64)) {
> + printk(KERN_ERR "%s: shm cap with bad size offset: %d"
> +"size: %d\n", __func__, pos, cap_len);
> + continue;
> + }
> +
> + pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
> + id), &id);
> + if (id != required_id)
> + continue;
> +
> + /* Type, and ID match, looks good */
> + pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
> + bar), bar);
> +
> + /* Read the lower 32bit of length and offset */
> + pci_read_config_dword(dev, pos + offsetof(struct virtio_pci_cap,
> + offset), &tmp32);
> + res_offset = tmp32;
> + pci_read_config_dword(dev, pos + offsetof(struct virtio_pci_cap,
> + length), &tmp32);
> + res_length = tmp32;
> +
> + /* and now the top half */
> + pci_read_config_dword(dev,
> + pos + offsetof(struct virtio_pci_cap64,
> + offset_hi), &tmp32);
> + res_offset |= ((u64)tmp32) << 32;
> + pci_read_config_dword(dev,
> + pos + offsetof(struct virtio_pci_cap64,
> + length_hi), &tmp32);
> + res_length |= ((u64)tmp32) << 32;
> +
> + *offset = res_offset;
> + *len = res_length;
> +
> + return pos;
> + }
> + return 0;
> +}
> +
> +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.
> +
> + region->len = len;
> + region->addr = (u64) phys_addr + offset;
> +
> + return true;
> +}
> +
> static const struct virtio_config_ops virtio_pci_config_nodev_ops = {
> .get= NULL,
> .set= NULL,
> @@ -458,6 +552,7 @@ static const struct virtio_config_ops
> vi
