On 2023-07-19 p.m.10:27, Jason Wang wrote:
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On Wed, Jul 19, 2023 at 11:46 PM Feng Liu <fe...@nvidia.com> wrote:
The 'is_legacy' flag is used to differentiate between legacy vs modern
device. Currently, it is based on the value of vp_dev->ldev.ioaddr.
However, due to the shared memory of the union between struct
virtio_pci_legacy_device and struct virtio_pci_modern_device, when
virtio_pci_modern_probe modifies the content of struct
virtio_pci_modern_device, it affects the content of struct
virtio_pci_legacy_device, and ldev.ioaddr is no longer zero, causing
the 'is_legacy' flag to be set as true. To resolve issue, when legacy
device is probed, mark 'is_legacy' as true, when modern device is
probed, keep 'is_legacy' as false.
Fixes: 4f0fc22534e3 ("virtio_pci: Optimize virtio_pci_device structure size")
Signed-off-by: Feng Liu <fe...@nvidia.com>
Reviewed-by: Parav Pandit <pa...@nvidia.com>
Reviewed-by: Jiri Pirko <j...@nvidia.com>
---
drivers/virtio/virtio_pci_common.c | 2 --
drivers/virtio/virtio_pci_legacy.c | 1 +
2 files changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/virtio/virtio_pci_common.c
b/drivers/virtio/virtio_pci_common.c
index a6c86f916dbd..c2524a7207cf 100644
--- a/drivers/virtio/virtio_pci_common.c
+++ b/drivers/virtio/virtio_pci_common.c
@@ -557,8 +557,6 @@ static int virtio_pci_probe(struct pci_dev *pci_dev,
pci_set_master(pci_dev);
- vp_dev->is_legacy = vp_dev->ldev.ioaddr ? true : false;
-
rc = register_virtio_device(&vp_dev->vdev);
reg_dev = vp_dev;
if (rc)
diff --git a/drivers/virtio/virtio_pci_legacy.c
b/drivers/virtio/virtio_pci_legacy.c
index 2257f1b3d8ae..d9cbb02b35a1 100644
--- a/drivers/virtio/virtio_pci_legacy.c
+++ b/drivers/virtio/virtio_pci_legacy.c
@@ -223,6 +223,7 @@ int virtio_pci_legacy_probe(struct virtio_pci_device
*vp_dev)
vp_dev->config_vector = vp_config_vector;
vp_dev->setup_vq = setup_vq;
vp_dev->del_vq = del_vq;
+ vp_dev->is_legacy = true;
This seems break force_legacy for modern device:
if (force_legacy) {
rc = virtio_pci_legacy_probe(vp_dev);
/* Also try modern mode if we can't map BAR0 (no IO space). */
if (rc == -ENODEV || rc == -ENOMEM)
rc = virtio_pci_modern_probe(vp_dev);
Thanks
Hi, Jason
In the case of force_legacy, if no IO space occurs, function will return
directly after vp_legacy_probe, and will not run vp_dev->is_legacy =
true; because vp_dev is allocated through kzalloc, the default
vp_dev->is_legacy is false, which It is expected for modern device, so
it will not break modern device.
What do you think?
int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
{
[...]
rc = vp_legacy_probe(ldev);
if (rc)
return rc; /* if no IO space, function will return from here */
[...]
vp_dev->is_legacy = true;
}
return 0;
}
--
2.37.1 (Apple Git-137.1)
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