* Re: [Qemu-devel] [PATCH V2 RFT] vhost_net: don't set backend for the uninitialized virtqueue [not found] ` <54169022-3b92-a49b-88b9-076e64a22e10@redhat.com> @ 2019-04-01 13:44 ` Michael S. Tsirkin 2019-04-08 6:51 ` Jason Wang 0 siblings, 1 reply; 3+ messages in thread From: Michael S. Tsirkin @ 2019-04-01 13:44 UTC (permalink / raw) To: Jason Wang; +Cc: yuri.benditovich, qemu-devel On Wed, Mar 27, 2019 at 10:27:01AM +0800, Jason Wang wrote: > > On 2019/3/26 下午8:49, Michael S. Tsirkin wrote: > > On Tue, Mar 26, 2019 at 02:59:19PM +0800, Jason Wang wrote: > > > On 2019/3/25 下午8:32, Michael S. Tsirkin wrote: > > > > On Mon, Mar 25, 2019 at 11:56:13AM +0800, Jason Wang wrote: > > > > > We used to set backend unconditionally, this won't work for some > > > > > guests (e.g windows driver) who may not initialize all virtqueues. For > > > > > kernel backend, this will fail since it may try to validate the rings > > > > > during setting backend. > > > > > > > > > > Fixing this by simply skipping the backend set when we find desc is > > > > > not ready. > > > > > > > > > > Signed-off-by: Jason Wang<jasowang@redhat.com> > > > > > --- > > > > > hw/net/vhost_net.c | 15 +++++++++++++++ > > > > > 1 file changed, 15 insertions(+) > > > > > > > > > > diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c > > > > > index be3cc88370..04fd924d15 100644 > > > > > --- a/hw/net/vhost_net.c > > > > > +++ b/hw/net/vhost_net.c > > > > > @@ -221,6 +221,7 @@ static int vhost_net_start_one(struct vhost_net *net, > > > > > VirtIODevice *dev) > > > > > { > > > > > struct vhost_vring_file file = { }; > > > > > + hwaddr a; > > > > > int r; > > > > > net->dev.nvqs = 2; > > > > > @@ -244,6 +245,13 @@ static int vhost_net_start_one(struct vhost_net *net, > > > > > qemu_set_fd_handler(net->backend, NULL, NULL, NULL); > > > > > file.fd = net->backend; > > > > > for (file.index = 0; file.index < net->dev.nvqs; ++file.index) { > > > > > + a = virtio_queue_get_desc_addr(dev, > > > > > + net->dev.vq_index + > > > > > + file.index); > > > > > + if (a == 0) { > > > > > + /* Queue might not be ready for start */ > > > > > + continue; > > > > > + } > > > > > r = vhost_net_set_backend(&net->dev, &file); > > > > > if (r < 0) { > > > > > r = -errno; > > > > > @@ -256,6 +264,13 @@ fail: > > > > > file.fd = -1; > > > > > if (net->nc->info->type == NET_CLIENT_DRIVER_TAP) { > > > > > while (file.index-- > 0) { > > > > > + a = virtio_queue_get_desc_addr(dev, > > > > > + net->dev.vq_index + > > > > > + file.index); > > > > > + if (a == 0) { > > > > > + /* Queue might not be ready for start */ > > > > > + continue; > > > > > + } > > > > > int r = vhost_net_set_backend(&net->dev, &file); > > > > > assert(r >= 0); > > > > > } > > > > I think we want an API that explicitly says "queue is enabled". > > > > For 0.X it will return !!addr. For 1.X it will return enabled. > > > For 1.x, desc.addr won't be set until queue_enabled is set through > > > virtio_queue_set_vrings(). And it looks to me ccw did something similar of > > > CMD_SET_VQ. > > > > > > So we're ok actually? > > > > > > Thanks > > > > > OK maybe but why can't we use an explicit API? > > 0.X can use addr != 0 trick since there's no queue_enabled. > > > > If I understand correctly, you want something similar to what V1 did? A bus > specific queue_enable() method. > > Thanks For now all I am asking for is simply: virtio_queue_is_enabled() { /* desc is only set when queue is enabled */ return vdev->vq[n].vring.desc != 0; } and then we can look at moving the enabled flag into struct VRing longer term. -- MST ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [Qemu-devel] [PATCH V2 RFT] vhost_net: don't set backend for the uninitialized virtqueue 2019-04-01 13:44 ` [Qemu-devel] [PATCH V2 RFT] vhost_net: don't set backend for the uninitialized virtqueue Michael S. Tsirkin @ 2019-04-08 6:51 ` Jason Wang 2019-04-08 6:51 ` Jason Wang 0 siblings, 1 reply; 3+ messages in thread From: Jason Wang @ 2019-04-08 6:51 UTC (permalink / raw) To: Michael S. Tsirkin; +Cc: yuri.benditovich, qemu-devel On 2019/4/1 下午9:44, Michael S. Tsirkin wrote: > On Wed, Mar 27, 2019 at 10:27:01AM +0800, Jason Wang wrote: >> On 2019/3/26 下午8:49, Michael S. Tsirkin wrote: >>> On Tue, Mar 26, 2019 at 02:59:19PM +0800, Jason Wang wrote: >>>> On 2019/3/25 下午8:32, Michael S. Tsirkin wrote: >>>>> On Mon, Mar 25, 2019 at 11:56:13AM +0800, Jason Wang wrote: >>>>>> We used to set backend unconditionally, this won't work for some >>>>>> guests (e.g windows driver) who may not initialize all virtqueues. For >>>>>> kernel backend, this will fail since it may try to validate the rings >>>>>> during setting backend. >>>>>> >>>>>> Fixing this by simply skipping the backend set when we find desc is >>>>>> not ready. >>>>>> >>>>>> Signed-off-by: Jason Wang<jasowang@redhat.com> >>>>>> --- >>>>>> hw/net/vhost_net.c | 15 +++++++++++++++ >>>>>> 1 file changed, 15 insertions(+) >>>>>> >>>>>> diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c >>>>>> index be3cc88370..04fd924d15 100644 >>>>>> --- a/hw/net/vhost_net.c >>>>>> +++ b/hw/net/vhost_net.c >>>>>> @@ -221,6 +221,7 @@ static int vhost_net_start_one(struct vhost_net *net, >>>>>> VirtIODevice *dev) >>>>>> { >>>>>> struct vhost_vring_file file = { }; >>>>>> + hwaddr a; >>>>>> int r; >>>>>> net->dev.nvqs = 2; >>>>>> @@ -244,6 +245,13 @@ static int vhost_net_start_one(struct vhost_net *net, >>>>>> qemu_set_fd_handler(net->backend, NULL, NULL, NULL); >>>>>> file.fd = net->backend; >>>>>> for (file.index = 0; file.index < net->dev.nvqs; ++file.index) { >>>>>> + a = virtio_queue_get_desc_addr(dev, >>>>>> + net->dev.vq_index + >>>>>> + file.index); >>>>>> + if (a == 0) { >>>>>> + /* Queue might not be ready for start */ >>>>>> + continue; >>>>>> + } >>>>>> r = vhost_net_set_backend(&net->dev, &file); >>>>>> if (r < 0) { >>>>>> r = -errno; >>>>>> @@ -256,6 +264,13 @@ fail: >>>>>> file.fd = -1; >>>>>> if (net->nc->info->type == NET_CLIENT_DRIVER_TAP) { >>>>>> while (file.index-- > 0) { >>>>>> + a = virtio_queue_get_desc_addr(dev, >>>>>> + net->dev.vq_index + >>>>>> + file.index); >>>>>> + if (a == 0) { >>>>>> + /* Queue might not be ready for start */ >>>>>> + continue; >>>>>> + } >>>>>> int r = vhost_net_set_backend(&net->dev, &file); >>>>>> assert(r >= 0); >>>>>> } >>>>> I think we want an API that explicitly says "queue is enabled". >>>>> For 0.X it will return !!addr. For 1.X it will return enabled. >>>> For 1.x, desc.addr won't be set until queue_enabled is set through >>>> virtio_queue_set_vrings(). And it looks to me ccw did something similar of >>>> CMD_SET_VQ. >>>> >>>> So we're ok actually? >>>> >>>> Thanks >>>> >>> OK maybe but why can't we use an explicit API? >>> 0.X can use addr != 0 trick since there's no queue_enabled. >>> >> If I understand correctly, you want something similar to what V1 did? A bus >> specific queue_enable() method. >> >> Thanks > For now all I am asking for is simply: > virtio_queue_is_enabled() { > /* desc is only set when queue is enabled */ > return vdev->vq[n].vring.desc != 0; > } > > and then we can look at moving the enabled flag into > struct VRing longer term. > > Ok, let me post V3. Thanks ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [Qemu-devel] [PATCH V2 RFT] vhost_net: don't set backend for the uninitialized virtqueue 2019-04-08 6:51 ` Jason Wang @ 2019-04-08 6:51 ` Jason Wang 0 siblings, 0 replies; 3+ messages in thread From: Jason Wang @ 2019-04-08 6:51 UTC (permalink / raw) To: Michael S. Tsirkin; +Cc: yuri.benditovich, qemu-devel On 2019/4/1 下午9:44, Michael S. Tsirkin wrote: > On Wed, Mar 27, 2019 at 10:27:01AM +0800, Jason Wang wrote: >> On 2019/3/26 下午8:49, Michael S. Tsirkin wrote: >>> On Tue, Mar 26, 2019 at 02:59:19PM +0800, Jason Wang wrote: >>>> On 2019/3/25 下午8:32, Michael S. Tsirkin wrote: >>>>> On Mon, Mar 25, 2019 at 11:56:13AM +0800, Jason Wang wrote: >>>>>> We used to set backend unconditionally, this won't work for some >>>>>> guests (e.g windows driver) who may not initialize all virtqueues. For >>>>>> kernel backend, this will fail since it may try to validate the rings >>>>>> during setting backend. >>>>>> >>>>>> Fixing this by simply skipping the backend set when we find desc is >>>>>> not ready. >>>>>> >>>>>> Signed-off-by: Jason Wang<jasowang@redhat.com> >>>>>> --- >>>>>> hw/net/vhost_net.c | 15 +++++++++++++++ >>>>>> 1 file changed, 15 insertions(+) >>>>>> >>>>>> diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c >>>>>> index be3cc88370..04fd924d15 100644 >>>>>> --- a/hw/net/vhost_net.c >>>>>> +++ b/hw/net/vhost_net.c >>>>>> @@ -221,6 +221,7 @@ static int vhost_net_start_one(struct vhost_net *net, >>>>>> VirtIODevice *dev) >>>>>> { >>>>>> struct vhost_vring_file file = { }; >>>>>> + hwaddr a; >>>>>> int r; >>>>>> net->dev.nvqs = 2; >>>>>> @@ -244,6 +245,13 @@ static int vhost_net_start_one(struct vhost_net *net, >>>>>> qemu_set_fd_handler(net->backend, NULL, NULL, NULL); >>>>>> file.fd = net->backend; >>>>>> for (file.index = 0; file.index < net->dev.nvqs; ++file.index) { >>>>>> + a = virtio_queue_get_desc_addr(dev, >>>>>> + net->dev.vq_index + >>>>>> + file.index); >>>>>> + if (a == 0) { >>>>>> + /* Queue might not be ready for start */ >>>>>> + continue; >>>>>> + } >>>>>> r = vhost_net_set_backend(&net->dev, &file); >>>>>> if (r < 0) { >>>>>> r = -errno; >>>>>> @@ -256,6 +264,13 @@ fail: >>>>>> file.fd = -1; >>>>>> if (net->nc->info->type == NET_CLIENT_DRIVER_TAP) { >>>>>> while (file.index-- > 0) { >>>>>> + a = virtio_queue_get_desc_addr(dev, >>>>>> + net->dev.vq_index + >>>>>> + file.index); >>>>>> + if (a == 0) { >>>>>> + /* Queue might not be ready for start */ >>>>>> + continue; >>>>>> + } >>>>>> int r = vhost_net_set_backend(&net->dev, &file); >>>>>> assert(r >= 0); >>>>>> } >>>>> I think we want an API that explicitly says "queue is enabled". >>>>> For 0.X it will return !!addr. For 1.X it will return enabled. >>>> For 1.x, desc.addr won't be set until queue_enabled is set through >>>> virtio_queue_set_vrings(). And it looks to me ccw did something similar of >>>> CMD_SET_VQ. >>>> >>>> So we're ok actually? >>>> >>>> Thanks >>>> >>> OK maybe but why can't we use an explicit API? >>> 0.X can use addr != 0 trick since there's no queue_enabled. >>> >> If I understand correctly, you want something similar to what V1 did? A bus >> specific queue_enable() method. >> >> Thanks > For now all I am asking for is simply: > virtio_queue_is_enabled() { > /* desc is only set when queue is enabled */ > return vdev->vq[n].vring.desc != 0; > } > > and then we can look at moving the enabled flag into > struct VRing longer term. > > Ok, let me post V3. Thanks ^ permalink raw reply [flat|nested] 3+ messages in thread
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2019-04-01 13:44 ` [Qemu-devel] [PATCH V2 RFT] vhost_net: don't set backend for the uninitialized virtqueue Michael S. Tsirkin
2019-04-08 6:51 ` Jason Wang
2019-04-08 6:51 ` Jason Wang
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