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authorSebastien Boeuf <sebastien.boeuf@intel.com>2020-08-19 18:19:42 -0400
committerMiklos Szeredi <mszeredi@redhat.com>2020-09-10 10:05:58 +0200
commit0dd4ff93f4c8dba016ad79384007da4938cd54a1 (patch)
tree133df8f4b7d0263b083bad6bfecfb5b7ab5d280d /drivers/virtio
parent5bfe37ca8ac8e9176bfd923d0a83802b7305d2f5 (diff)
virtio: Implement get_shm_region for PCI transport
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> Acked-by: Michael S. Tsirkin <mst@redhat.com> Cc: kvm@vger.kernel.org Cc: virtualization@lists.linux-foundation.org Cc: "Michael S. Tsirkin" <mst@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'drivers/virtio')
-rw-r--r--drivers/virtio/virtio_pci_modern.c95
1 files changed, 95 insertions, 0 deletions
diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c
index 3e14e700b231..3d6ae5a5e252 100644
--- a/drivers/virtio/virtio_pci_modern.c
+++ b/drivers/virtio/virtio_pci_modern.c
@@ -444,6 +444,99 @@ 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)) {
+ dev_err(&dev->dev, "%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;
+ }
+
+ 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 +551,7 @@ static const struct virtio_config_ops virtio_pci_config_nodev_ops = {
.bus_name = vp_bus_name,
.set_vq_affinity = vp_set_vq_affinity,
.get_vq_affinity = vp_get_vq_affinity,
+ .get_shm_region = vp_get_shm_region,
};
static const struct virtio_config_ops virtio_pci_config_ops = {
@@ -474,6 +568,7 @@ static const struct virtio_config_ops virtio_pci_config_ops = {
.bus_name = vp_bus_name,
.set_vq_affinity = vp_set_vq_affinity,
.get_vq_affinity = vp_get_vq_affinity,
+ .get_shm_region = vp_get_shm_region,
};
/**