Current virtio-net only probes a device with VIRITO_ID_NET == 1.
For a modern-transtional virtio-net device which has a transtional
device id 0x1000 and acts as a modern device, current virtio-pci
modern driver will assign the sub-device-id to its mdev->id.device,
which may not be 0x1, this sub-device-id is up to the vendor.
That means virtio-net driver doesn't probe a modern-transitonal
virtio-net with a sub-device-id other than 0x1, which is a bug.
Other types of devices also have similar issues, like virito-blk.
I propose to fix this problem of modern-transitonal device
whith this solution, all in the modern code path:
1) assign the device id to mdev->id.device
2) add transitional device ids in the virtio-net(and others) probe table.
Comments are welcome!
Thanks!
Signed-off-by: Zhu Lingshan <lingshan.zhu at intel.com>
---
drivers/net/virtio_net.c | 1 +
drivers/virtio/virtio_pci_modern_dev.c | 2 +-
2 files changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 56ca1d270304..6b45d8602a6b 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -4250,6 +4250,7 @@ static __maybe_unused int virtnet_restore(struct
virtio_device *vdev)
static struct virtio_device_id id_table[] = {
{ VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
+ { VIRTIO_TRANS_ID_NET, VIRTIO_DEV_ANY_ID },
{ 0 },
};
diff --git a/drivers/virtio/virtio_pci_modern_dev.c
b/drivers/virtio/virtio_pci_modern_dev.c
index 869cb46bef96..80846e1195ce 100644
--- a/drivers/virtio/virtio_pci_modern_dev.c
+++ b/drivers/virtio/virtio_pci_modern_dev.c
@@ -229,7 +229,7 @@ int vp_modern_probe(struct virtio_pci_modern_device *mdev)
/* Transitional devices: use the PCI subsystem device id as
* virtio device id, same as legacy driver always did.
*/
- mdev->id.device = pci_dev->subsystem_device;
+ mdev->id.device = pci_dev->device;
} else {
/* Modern devices: simply use PCI device id, but start from 0x1040. */
mdev->id.device = pci_dev->device - 0x1040;
--
2.39.1
Michael S. Tsirkin
2023-May-28 11:28 UTC
[RFC] virtio-net: support modern-transtional devices
On Sat, May 27, 2023 at 02:15:42AM +0800, Zhu Lingshan wrote:> Current virtio-net only probes a device with VIRITO_ID_NET == 1. > > For a modern-transtional virtio-net device which has a transtional > device id 0x1000 and acts as a modern device, current virtio-pci > modern driver will assign the sub-device-id to its mdev->id.device, > which may not be 0x1, this sub-device-id is up to the vendor. > > That means virtio-net driver doesn't probe a modern-transitonal > virtio-net with a sub-device-id other than 0x1, which is a bug.No, the bug is in the device. Legacy linux drivers always looked at sub device id (other OSes might differ). So it makes no sense for a transitional device to have sub-device-id other than 0x1. Don't have time to look at spec but I think you will find it there.> Other types of devices also have similar issues, like virito-blk. > > I propose to fix this problem of modern-transitonal device > whith this solution, all in the modern code path: > 1) assign the device id to mdev->id.device > 2) add transitional device ids in the virtio-net(and others) probe table. > > Comments are welcome! > > Thanks! > > Signed-off-by: Zhu Lingshan <lingshan.zhu at intel.com> > --- > drivers/net/virtio_net.c | 1 + > drivers/virtio/virtio_pci_modern_dev.c | 2 +- > 2 files changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index 56ca1d270304..6b45d8602a6b 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -4250,6 +4250,7 @@ static __maybe_unused int virtnet_restore(struct virtio_device *vdev) > > static struct virtio_device_id id_table[] = { > { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID }, > + { VIRTIO_TRANS_ID_NET, VIRTIO_DEV_ANY_ID }, > { 0 }, > }; > > diff --git a/drivers/virtio/virtio_pci_modern_dev.c b/drivers/virtio/virtio_pci_modern_dev.c > index 869cb46bef96..80846e1195ce 100644 > --- a/drivers/virtio/virtio_pci_modern_dev.c > +++ b/drivers/virtio/virtio_pci_modern_dev.c > @@ -229,7 +229,7 @@ int vp_modern_probe(struct virtio_pci_modern_device *mdev) > /* Transitional devices: use the PCI subsystem device id as > * virtio device id, same as legacy driver always did. > */ > - mdev->id.device = pci_dev->subsystem_device; > + mdev->id.device = pci_dev->device; > } else { > /* Modern devices: simply use PCI device id, but start from 0x1040. */ > mdev->id.device = pci_dev->device - 0x1040; > -- > 2.39.1