On Sat, Oct 30, 2021 at 2:36 AM Eugenio Pérez <eperezma@xxxxxxxxxx> wrote: > > Implementation of RFC of device state capability: > https://lists.oasis-open.org/archives/virtio-comment/202012/msg00005.html Considering this still requires time to be done, we need to think of a way to go without this. Thanks > > With this capability, vdpa device can reset it's index so it can start > consuming from guest after disabling shadow virtqueue (SVQ), with state > not 0. > > 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@xxxxxxxxxx> > --- > 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(-) > > diff --git a/hw/virtio/virtio-pci.h b/hw/virtio/virtio-pci.h > index 2446dcd9ae..019badbd7c 100644 > --- a/hw/virtio/virtio-pci.h > +++ b/hw/virtio/virtio-pci.h > @@ -120,6 +120,7 @@ typedef struct VirtIOPCIQueue { > uint32_t desc[2]; > uint32_t avail[2]; > uint32_t used[2]; > + uint16_t state; > } VirtIOPCIQueue; > > struct VirtIOPCIProxy { > diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h > index 8bab9cfb75..5fe575b8f0 100644 > --- a/include/hw/virtio/virtio.h > +++ b/include/hw/virtio/virtio.h > @@ -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); > diff --git a/include/standard-headers/linux/virtio_config.h b/include/standard-headers/linux/virtio_config.h > index 22e3a85f67..59fad3eb45 100644 > --- a/include/standard-headers/linux/virtio_config.h > +++ b/include/standard-headers/linux/virtio_config.h > @@ -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 */ > diff --git a/include/standard-headers/linux/virtio_pci.h b/include/standard-headers/linux/virtio_pci.h > index db7a8e2fcb..c8d9802a87 100644 > --- a/include/standard-headers/linux/virtio_pci.h > +++ b/include/standard-headers/linux/virtio_pci.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 */ > > diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c > index 750aa47ec1..d7bb549033 100644 > --- a/hw/virtio/virtio-pci.c > +++ b/hw/virtio/virtio-pci.c > @@ -1244,6 +1244,9 @@ 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; > } > @@ -1330,6 +1333,8 @@ 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); > @@ -1353,6 +1358,9 @@ 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; > } > @@ -1951,6 +1959,7 @@ 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)) { > -- > 2.27.0 > _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
