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Re: [Qemu-devel] [PATCH V3 6/6] virtio-pci: unbreak queue_enable read
From: |
Jason Wang |
Subject: |
Re: [Qemu-devel] [PATCH V3 6/6] virtio-pci: unbreak queue_enable read |
Date: |
Tue, 10 Nov 2015 10:51:21 +0800 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 |
On 11/09/2015 09:14 PM, Cornelia Huck wrote:
> On Fri, 6 Nov 2015 16:02:49 +0800
> Jason Wang <address@hidden> wrote:
>
>> Guest always get zero when reading queue_enable. This violates
>> spec. Fixing this by setting the queue_enable to true during any guest
>> writing and setting it to zero during reset.
>>
>> Cc: Michael S. Tsirkin <address@hidden>
>> Signed-off-by: Jason Wang <address@hidden>
>> ---
>> hw/virtio/virtio-pci.c | 7 +++++++
>> 1 file changed, 7 insertions(+)
>>
>> diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
>> index e4449da..52a9e33 100644
>> --- a/hw/virtio/virtio-pci.c
>> +++ b/hw/virtio/virtio-pci.c
>> @@ -1384,6 +1384,7 @@ 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]);
>> + proxy->vqs[vdev->queue_sel].enabled = 1;
> Hm. Spec says that the driver MUST NOT write 0 here.
Yes.
> Does this need a
> check?
Add warn in this case? I'm not sure, I read the spec as "writing any
value implies enabling". (And the patch itself does not conflict the spec).
>
> <Also, I think you can remove the 'TODO' comment - this should be
> handled now.>
Yes
>
>> break;
>> case VIRTIO_PCI_COMMON_Q_DESCLO:
>> proxy->vqs[vdev->queue_sel].desc[0] = val;
>> @@ -1831,9 +1832,15 @@ static void virtio_pci_reset(DeviceState *qdev)
>> {
>> VirtIOPCIProxy *proxy = VIRTIO_PCI(qdev);
>> VirtioBusState *bus = VIRTIO_BUS(&proxy->bus);
>> + int i;
>> +
>> virtio_pci_stop_ioeventfd(proxy);
>> virtio_bus_reset(bus);
>> msix_unuse_all_vectors(&proxy->pci_dev);
>> +
>> + for (i = 0; i < VIRTIO_QUEUE_MAX; i++) {
>> + proxy->vqs[i].enabled = 0;
>> + }
>> }
>>
>> static Property virtio_pci_properties[] = {
> Otherwise, this looks good to me.
>
>
Thanks
- [Qemu-devel] [PATCH V3 1/6] virtio-pci: fix 1.0 virtqueue migration, (continued)
- [Qemu-devel] [PATCH V3 1/6] virtio-pci: fix 1.0 virtqueue migration, Jason Wang, 2015/11/06
- [Qemu-devel] [PATCH V3 2/6] memory: don't try to adjust endianness for zero length eventfd, Jason Wang, 2015/11/06
- [Qemu-devel] [PATCH V3 3/6] KVM: add support for any length io eventfd, Jason Wang, 2015/11/06
- [Qemu-devel] [PATCH V3 4/6] virtio-pci: use zero length mmio eventfd for 1.0 notification cap when possible, Jason Wang, 2015/11/06
- [Qemu-devel] [PATCH V3 5/6] virtio-pci: introduce pio notification capability for modern device, Jason Wang, 2015/11/06
- [Qemu-devel] [PATCH V3 6/6] virtio-pci: unbreak queue_enable read, Jason Wang, 2015/11/06