@@ -115,6 +115,7 @@ typedef struct VirtIOPCIQueue {
uint32_t desc[2];
uint32_t avail[2];
uint32_t used[2];
+ uint16_t state;
} VirtIOPCIQueue;
struct VirtIOPCIProxy {
@@ -289,7 +289,9 @@ typedef struct VirtIORNGConf VirtIORNGConf;
DEFINE_PROP_BIT64("iommu_platform", _state, _field, \
VIRTIO_F_IOMMU_PLATFORM, false), \
DEFINE_PROP_BIT64("packed", _state, _field, \
- VIRTIO_F_RING_PACKED, false)
+ VIRTIO_F_RING_PACKED, false), \
+ DEFINE_PROP_BIT64("save_restore_q_state", _state, _field, \
+ VIRTIO_F_QUEUE_STATE, true)
hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n);
bool virtio_queue_enabled_legacy(VirtIODevice *vdev, int n);
@@ -90,4 +90,7 @@
* Does the device support Single Root I/O Virtualization?
*/
#define VIRTIO_F_SR_IOV 37
+
+/* Device support save and restore virtqueue state */
+#define VIRTIO_F_QUEUE_STATE 40
#endif /* _LINUX_VIRTIO_CONFIG_H */
@@ -164,6 +164,7 @@ struct virtio_pci_common_cfg {
uint32_t queue_avail_hi; /* read-write */
uint32_t queue_used_lo; /* read-write */
uint32_t queue_used_hi; /* read-write */
+ uint16_t queue_avail_state; /* read-write */
};
/* Fields in VIRTIO_PCI_CAP_PCI_CFG: */
@@ -202,6 +203,7 @@ struct virtio_pci_cfg_cap {
#define VIRTIO_PCI_COMMON_Q_AVAILHI 44
#define VIRTIO_PCI_COMMON_Q_USEDLO 48
#define VIRTIO_PCI_COMMON_Q_USEDHI 52
+#define VIRTIO_PCI_COMMON_Q_AVAIL_STATE 56
#endif /* VIRTIO_PCI_NO_MODERN */
@@ -1216,6 +1216,9 @@ static uint64_t virtio_pci_common_read(void *opaque, hwaddr addr,
case VIRTIO_PCI_COMMON_Q_USEDHI:
val = proxy->vqs[vdev->queue_sel].used[1];
break;
+ case VIRTIO_PCI_COMMON_Q_AVAIL_STATE:
+ val = virtio_queue_get_last_avail_idx(vdev, vdev->queue_sel);
+ break;
default:
val = 0;
}
@@ -1298,6 +1301,8 @@ static void virtio_pci_common_write(void *opaque, hwaddr addr,
proxy->vqs[vdev->queue_sel].avail[0],
((uint64_t)proxy->vqs[vdev->queue_sel].used[1]) << 32 |
proxy->vqs[vdev->queue_sel].used[0]);
+ virtio_queue_set_last_avail_idx(vdev, vdev->queue_sel,
+ proxy->vqs[vdev->queue_sel].state);
proxy->vqs[vdev->queue_sel].enabled = 1;
} else {
virtio_error(vdev, "wrong value for queue_enable %"PRIx64, val);
@@ -1321,6 +1326,9 @@ static void virtio_pci_common_write(void *opaque, hwaddr addr,
case VIRTIO_PCI_COMMON_Q_USEDHI:
proxy->vqs[vdev->queue_sel].used[1] = val;
break;
+ case VIRTIO_PCI_COMMON_Q_AVAIL_STATE:
+ proxy->vqs[vdev->queue_sel].state = val;
+ break;
default:
break;
}
@@ -1900,6 +1908,7 @@ static void virtio_pci_reset(DeviceState *qdev)
proxy->vqs[i].desc[0] = proxy->vqs[i].desc[1] = 0;
proxy->vqs[i].avail[0] = proxy->vqs[i].avail[1] = 0;
proxy->vqs[i].used[0] = proxy->vqs[i].used[1] = 0;
+ proxy->vqs[i].state = 0;
}
if (pci_is_express(dev)) {
Implementation of RFC of device state capability: https://lists.oasis-open.org/archives/virtio-comment/202012/msg00005.html With this capability, vdpa device can reset it's index so it can start consuming from shadow virtqueue (SVQ), that start with state 0. Another approach would be to make SVQ to start forwarding from the state of the device when the later is stopped, but this device capability is needed at the destination of live migration anyway. The use case is to test SVQ with virtio-pci vdpa (vp_vdpa) with nested virtualization. Spawning a L0 qemu with a virtio-net device, use vp_vdpa driver to handle it in the guest, and then spawn a L1 qemu using that vdpa device. When L1 qemu calls device to set a new state though vdpa ioctl, vp_vdpa should set each queue state though virtio VIRTIO_PCI_COMMON_Q_AVAIL_STATE. Since this is only for testing vhost-vdpa, it's added here before of proposing to kernel code. No effort is done for checking that device can actually change its state, its layout, or if the device even supports to change state at all. These will be added in the future. Also, a modified version of vp_vdpa that allows to set these in PCI config is needed. TODO: Check for feature enabled and split in virtio pci config Signed-off-by: Eugenio Pérez <eperezma@redhat.com> --- hw/virtio/virtio-pci.h | 1 + include/hw/virtio/virtio.h | 4 +++- include/standard-headers/linux/virtio_config.h | 3 +++ include/standard-headers/linux/virtio_pci.h | 2 ++ hw/virtio/virtio-pci.c | 9 +++++++++ 5 files changed, 18 insertions(+), 1 deletion(-)