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SubjectRe: [PATCH 04/19] virtio: Implement get_shm_region for PCI transport
On Tue, Aug 27, 2019 at 10:34:57AM +0200, Cornelia Huck wrote:
> On Wed, 21 Aug 2019 13:57:05 -0400
> Vivek Goyal <vgoyal@redhat.com> 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.
> >
> > Cc: kvm@vger.kernel.org
> > 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>
>
> An s-o-b by a test robot looks a bit odd.

I think one of the fixes came from the robot and that's why I put s-o-b
from the robot as well.

I will review the whole patch and fix all the intendation issues.

Vivek

>
> > ---
> > drivers/virtio/virtio_pci_modern.c | 108 +++++++++++++++++++++++++++++
> > include/uapi/linux/virtio_pci.h | 11 ++-
> > 2 files changed, 118 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c
> > index 7abcc50838b8..1cdedd93f42a 100644
> > --- a/drivers/virtio/virtio_pci_modern.c
> > +++ b/drivers/virtio/virtio_pci_modern.c
> > @@ -443,6 +443,112 @@ 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);
>
> Indentation looks a bit off here.
>
> > + pos > 0;
> > + pos = pci_find_next_capability(dev, pos, PCI_CAP_ID_VNDR)) {
> > + u8 type, cap_len, id;
> > + u32 tmp32;
>
> Here as well.
>
> > + 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)
>
> And here.
>
> > + 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);
>
> Probably better to use dev_warn() instead of printk.
>
> > + continue;
> > + }
>
> Indentation looks off again (might be a space vs tabs issue; maybe
> check the whole patch for indentation problems?)
>
> > +
> > + 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);
>
> This whole function looks like it is indented incorrectly.
>
> > + struct pci_dev *pci_dev = vp_dev->pci_dev;
> > + u8 bar;
> > + u64 offset, len;
> > + phys_addr_t phys_addr;
> > + size_t bar_len;
> > + char *bar_name;
> > + int ret;
> > +
> > + if (!virtio_pci_find_shm_cap(pci_dev, id, &bar, &offset, &len)) {
> > + return false;
> > + }
>
> You can drop the curly braces.
>
> > +
> > + ret = pci_request_region(pci_dev, bar, "virtio-pci-shm");
> > + if (ret < 0) {
> > + dev_err(&pci_dev->dev, "%s: failed to request BAR\n",
> > + __func__);
> > + return false;
> > + }
> > +
> > + phys_addr = pci_resource_start(pci_dev, bar);
> > + bar_len = pci_resource_len(pci_dev, bar);
> > +
> > + if (offset + len > bar_len) {
> > + dev_err(&pci_dev->dev,
> > + "%s: bar shorter than cap offset+len\n",
> > + __func__);
> > + return false;
> > + }
> > +
> > + 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,
>
> Apart from the coding style nits, the logic of the patch looks sane to
> me.
>
> (...)
>
> As does the rest of the patch.

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