Patchwork [RFC,1/9] virtio: Add support for guest setting of queue size

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Submitter Evgeny Voevodin
Date April 25, 2012, 5:54 a.m.
Message ID <1335333257-5128-2-git-send-email-e.voevodin@samsung.com>
Download mbox | patch
Permalink /patch/154798/
State New
Headers show

Comments

Evgeny Voevodin - April 25, 2012, 5:54 a.m.
From: Peter Maydell <peter.maydell@linaro.org>

The MMIO virtio transport spec allows the guest to tell the host how
large the queue size is. Add virtio_queue_set_num() function which
implements this in the QEMU common virtio support code.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Evgeny Voevodin <e.voevodin@samsung.com>
---
 hw/virtio.c |    6 ++++++
 hw/virtio.h |    1 +
 2 files changed, 7 insertions(+), 0 deletions(-)

Patch

diff --git a/hw/virtio.c b/hw/virtio.c
index 314abf8..71c4a10 100644
--- a/hw/virtio.c
+++ b/hw/virtio.c
@@ -619,6 +619,12 @@  target_phys_addr_t virtio_queue_get_addr(VirtIODevice *vdev, int n)
     return vdev->vq[n].pa;
 }
 
+void virtio_queue_set_num(VirtIODevice *vdev, int n, int num)
+{
+    vdev->vq[n].vring.num = num;
+    virtqueue_init(&vdev->vq[n]);
+}
+
 int virtio_queue_get_num(VirtIODevice *vdev, int n)
 {
     return vdev->vq[n].vring.num;
diff --git a/hw/virtio.h b/hw/virtio.h
index 0aef7d1..72b56e3 100644
--- a/hw/virtio.h
+++ b/hw/virtio.h
@@ -178,6 +178,7 @@  void virtio_config_writew(VirtIODevice *vdev, uint32_t addr, uint32_t data);
 void virtio_config_writel(VirtIODevice *vdev, uint32_t addr, uint32_t data);
 void virtio_queue_set_addr(VirtIODevice *vdev, int n, target_phys_addr_t addr);
 target_phys_addr_t virtio_queue_get_addr(VirtIODevice *vdev, int n);
+void virtio_queue_set_num(VirtIODevice *vdev, int n, int num);
 int virtio_queue_get_num(VirtIODevice *vdev, int n);
 void virtio_queue_notify(VirtIODevice *vdev, int n);
 uint16_t virtio_queue_vector(VirtIODevice *vdev, int n);