Michael S. Tsirkin
2023-Jul-20 17:14 UTC
[PATCH v1] virtio-pci: Fix legacy device flag setting error in probe
On Thu, Jul 20, 2023 at 10:27:04AM +0800, Jason Wang wrote:> On Wed, Jul 19, 2023 at 11:46?PM Feng Liu <feliu at 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 <feliu at nvidia.com> > > Reviewed-by: Parav Pandit <parav at nvidia.com> > > Reviewed-by: Jiri Pirko <jiri at 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); > > Thanksdon't see the breakage here - can you explain a bit more?> > > > return 0; > > } > > -- > > 2.37.1 (Apple Git-137.1) > >
Feng Liu
2023-Jul-24 13:14 UTC
[PATCH v1] virtio-pci: Fix legacy device flag setting error in probe
On 2023-07-20 p.m.1:14, Michael S. Tsirkin wrote:> External email: Use caution opening links or attachments > > > On Thu, Jul 20, 2023 at 10:27:04AM +0800, Jason Wang wrote: >> On Wed, Jul 19, 2023 at 11:46?PM Feng Liu <feliu at 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 <feliu at nvidia.com> >>> Reviewed-by: Parav Pandit <parav at nvidia.com> >>> Reviewed-by: Jiri Pirko <jiri at 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 > > don't see the breakage here - can you explain a bit more? >Hi, Jason I also think there is no breakage herea and gave an explanation in another email, please have a see. So are there any comments about this bug fix patch? Can this patch pass the review? Thanks Feng>>> >>> return 0; >>> } >>> -- >>> 2.37.1 (Apple Git-137.1) >>> >