From: Laurent Vivier <lvivier@redhat.com>
To: qemu-devel@nongnu.org
Cc: Juan Quintela <quintela@redhat.com>,
Jason Wang <jasowang@redhat.com>,
Jens Freimann <jfreimann@redhat.com>,
"Michael S. Tsirkin" <mst@redhat.com>
Subject: [PATCH 1/2] virtio: add a way to disable a queue
Date: Thu, 29 Jul 2021 21:19:09 +0200 [thread overview]
Message-ID: <20210729191910.317114-2-lvivier@redhat.com> (raw)
In-Reply-To: <20210729191910.317114-1-lvivier@redhat.com>
Add virtio_queue_disable()/virtio_queue_enable() to disable/enable a queue
by setting vring.num to 0 (or num_default).
This is needed to be able to disable a guest driver from the host side
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
---
include/hw/virtio/virtio.h | 2 ++
hw/virtio/virtio.c | 10 ++++++++++
2 files changed, 12 insertions(+)
diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
index 8bab9cfb7507..6a3f71b4cd88 100644
--- a/include/hw/virtio/virtio.h
+++ b/include/hw/virtio/virtio.h
@@ -251,6 +251,8 @@ void virtio_config_modern_writel(VirtIODevice *vdev,
uint32_t addr, uint32_t data);
void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr);
hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n);
+void virtio_queue_enable(VirtIODevice *vdev, int n);
+void virtio_queue_disable(VirtIODevice *vdev, int n);
void virtio_queue_set_num(VirtIODevice *vdev, int n, int num);
int virtio_queue_get_num(VirtIODevice *vdev, int n);
int virtio_queue_get_max_num(VirtIODevice *vdev, int n);
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 874377f37a70..fa5228c1a2d6 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -2244,6 +2244,16 @@ void virtio_queue_set_rings(VirtIODevice *vdev, int n, hwaddr desc,
virtio_init_region_cache(vdev, n);
}
+void virtio_queue_disable(VirtIODevice *vdev, int n)
+{
+ vdev->vq[n].vring.num = 0;
+}
+
+void virtio_queue_enable(VirtIODevice *vdev, int n)
+{
+ vdev->vq[n].vring.num = vdev->vq[n].vring.num_default;
+}
+
void virtio_queue_set_num(VirtIODevice *vdev, int n, int num)
{
/* Don't allow guest to flip queue between existent and
--
2.31.1
next prev parent reply other threads:[~2021-07-29 19:22 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-29 19:19 [PATCH 0/2] virtio: failover: allow to keep the VFIO device rather than the virtio-net one Laurent Vivier
2021-07-29 19:19 ` Laurent Vivier [this message]
2021-08-02 4:50 ` [PATCH 1/2] virtio: add a way to disable a queue Jason Wang
2021-08-02 8:42 ` Laurent Vivier
2021-08-06 6:25 ` Jason Wang
2021-08-06 7:27 ` Laurent Vivier
2021-08-09 3:01 ` Jason Wang
2021-08-09 16:12 ` Laurent Vivier
2021-07-29 19:19 ` [PATCH 2/2] virtio: failover: define the default device to use in case of error Laurent Vivier
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