From cf39b82860b63589460d8797dd70ae3c1647ccca Mon Sep 17 00:00:00 2001 From: Jonah Palmer Date: Fri, 15 Mar 2024 12:55:52 -0400 Subject: [PATCH] virtio/virtio-pci: Handle extra notification data MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add support to virtio-pci devices for handling the extra data sent from the driver to the device when the VIRTIO_F_NOTIFICATION_DATA transport feature has been negotiated. The extra data that's passed to the virtio-pci device when this feature is enabled varies depending on the device's virtqueue layout. In a split virtqueue layout, this data includes: - upper 16 bits: shadow_avail_idx - lower 16 bits: virtqueue index In a packed virtqueue layout, this data includes: - upper 16 bits: 1-bit wrap counter & 15-bit shadow_avail_idx - lower 16 bits: virtqueue index Signed-off-by: Jonah Palmer Message-Id: <20240315165557.26942-2-jonah.palmer@oracle.com> Reviewed-by: Eugenio Pérez Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/virtio/virtio-pci.c | 12 +++++++++--- hw/virtio/virtio.c | 18 ++++++++++++++++++ include/hw/virtio/virtio.h | 2 ++ 3 files changed, 29 insertions(+), 3 deletions(-) diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c index b1d02f4b3d..cffc7efcae 100644 --- a/hw/virtio/virtio-pci.c +++ b/hw/virtio/virtio-pci.c @@ -384,7 +384,7 @@ static void virtio_ioport_write(void *opaque, uint32_t addr, uint32_t val) { VirtIOPCIProxy *proxy = opaque; VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus); - uint16_t vector; + uint16_t vector, vq_idx; hwaddr pa; switch (addr) { @@ -408,8 +408,14 @@ static void virtio_ioport_write(void *opaque, uint32_t addr, uint32_t val) vdev->queue_sel = val; break; case VIRTIO_PCI_QUEUE_NOTIFY: - if (val < VIRTIO_QUEUE_MAX) { - virtio_queue_notify(vdev, val); + vq_idx = val; + if (vq_idx < VIRTIO_QUEUE_MAX && virtio_queue_get_num(vdev, vq_idx)) { + if (virtio_vdev_has_feature(vdev, VIRTIO_F_NOTIFICATION_DATA)) { + VirtQueue *vq = virtio_get_queue(vdev, vq_idx); + + virtio_queue_set_shadow_avail_idx(vq, val >> 16); + } + virtio_queue_notify(vdev, vq_idx); } break; case VIRTIO_PCI_STATUS: diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 893a072c9d..f7c99e3a96 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -2264,6 +2264,24 @@ void virtio_queue_set_align(VirtIODevice *vdev, int n, int align) } } +void virtio_queue_set_shadow_avail_idx(VirtQueue *vq, uint16_t shadow_avail_idx) +{ + if (!vq->vring.desc) { + return; + } + + /* + * 16-bit data for packed VQs include 1-bit wrap counter and + * 15-bit shadow_avail_idx. + */ + if (virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED)) { + vq->shadow_avail_wrap_counter = (shadow_avail_idx >> 15) & 0x1; + vq->shadow_avail_idx = shadow_avail_idx & 0x7FFF; + } else { + vq->shadow_avail_idx = shadow_avail_idx; + } +} + static void virtio_queue_notify_vq(VirtQueue *vq) { if (vq->vring.desc && vq->handle_output) { diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h index 7d5ffdc145..1451926a13 100644 --- a/include/hw/virtio/virtio.h +++ b/include/hw/virtio/virtio.h @@ -307,6 +307,8 @@ int virtio_queue_ready(VirtQueue *vq); int virtio_queue_empty(VirtQueue *vq); +void virtio_queue_set_shadow_avail_idx(VirtQueue *vq, uint16_t idx); + /* Host binding interface. */ uint32_t virtio_config_readb(VirtIODevice *vdev, uint32_t addr);