Jason Wang
2021-Apr-08 08:58 UTC
[PATCH v2 1/3] virtio: update reset callback to return status
? 2021/4/8 ??4:11, Max Gurtovoy ??:> The reset device operation, usually is an operation that might fail from > various reasons. For example, the controller might be in a bad state and > can't answer to any request. Usually, the paravirt SW based virtio > devices always succeed in reset operation but this is not the case for > HW based virtio devices.I would like to know under what condition that the reset operation may fail (except for the case of a bugg guest).> > This commit is also a preparation for adding a timeout mechanism for > resetting virtio devices. > > Signed-off-by: Max Gurtovoy <mgurtovoy at nvidia.com> > --- > > changes from v1: > - update virtio_ccw.c (Cornelia) > - update virtio_uml.c > - update mlxbf-tmfifo.cNote that virtio driver may call reset, so you probably need to convert them. Thanks> > --- > arch/um/drivers/virtio_uml.c | 4 +++- > drivers/platform/mellanox/mlxbf-tmfifo.c | 4 +++- > drivers/remoteproc/remoteproc_virtio.c | 4 +++- > drivers/s390/virtio/virtio_ccw.c | 9 ++++++--- > drivers/virtio/virtio.c | 22 +++++++++++++++------- > drivers/virtio/virtio_mmio.c | 3 ++- > drivers/virtio/virtio_pci_legacy.c | 4 +++- > drivers/virtio/virtio_pci_modern.c | 3 ++- > drivers/virtio/virtio_vdpa.c | 4 +++- > include/linux/virtio_config.h | 5 +++-- > 10 files changed, 43 insertions(+), 19 deletions(-) > > diff --git a/arch/um/drivers/virtio_uml.c b/arch/um/drivers/virtio_uml.c > index 91ddf74ca888..b6e66265ed32 100644 > --- a/arch/um/drivers/virtio_uml.c > +++ b/arch/um/drivers/virtio_uml.c > @@ -827,11 +827,13 @@ static void vu_set_status(struct virtio_device *vdev, u8 status) > vu_dev->status = status; > } > > -static void vu_reset(struct virtio_device *vdev) > +static int vu_reset(struct virtio_device *vdev) > { > struct virtio_uml_device *vu_dev = to_virtio_uml_device(vdev); > > vu_dev->status = 0; > + > + return 0; > } > > static void vu_del_vq(struct virtqueue *vq) > diff --git a/drivers/platform/mellanox/mlxbf-tmfifo.c b/drivers/platform/mellanox/mlxbf-tmfifo.c > index bbc4e71a16ff..c192b8ac5d9e 100644 > --- a/drivers/platform/mellanox/mlxbf-tmfifo.c > +++ b/drivers/platform/mellanox/mlxbf-tmfifo.c > @@ -980,11 +980,13 @@ static void mlxbf_tmfifo_virtio_set_status(struct virtio_device *vdev, > } > > /* Reset the device. Not much here for now. */ > -static void mlxbf_tmfifo_virtio_reset(struct virtio_device *vdev) > +static int mlxbf_tmfifo_virtio_reset(struct virtio_device *vdev) > { > struct mlxbf_tmfifo_vdev *tm_vdev = mlxbf_vdev_to_tmfifo(vdev); > > tm_vdev->status = 0; > + > + return 0; > } > > /* Read the value of a configuration field. */ > diff --git a/drivers/remoteproc/remoteproc_virtio.c b/drivers/remoteproc/remoteproc_virtio.c > index 0cc617f76068..ca9573c62c3d 100644 > --- a/drivers/remoteproc/remoteproc_virtio.c > +++ b/drivers/remoteproc/remoteproc_virtio.c > @@ -191,7 +191,7 @@ static void rproc_virtio_set_status(struct virtio_device *vdev, u8 status) > dev_dbg(&vdev->dev, "status: %d\n", status); > } > > -static void rproc_virtio_reset(struct virtio_device *vdev) > +static int rproc_virtio_reset(struct virtio_device *vdev) > { > struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); > struct fw_rsc_vdev *rsc; > @@ -200,6 +200,8 @@ static void rproc_virtio_reset(struct virtio_device *vdev) > > rsc->status = 0; > dev_dbg(&vdev->dev, "reset !\n"); > + > + return 0; > } > > /* provide the vdev features as retrieved from the firmware */ > diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c > index 54e686dca6de..52b32555e746 100644 > --- a/drivers/s390/virtio/virtio_ccw.c > +++ b/drivers/s390/virtio/virtio_ccw.c > @@ -732,14 +732,15 @@ static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs, > return ret; > } > > -static void virtio_ccw_reset(struct virtio_device *vdev) > +static int virtio_ccw_reset(struct virtio_device *vdev) > { > struct virtio_ccw_device *vcdev = to_vc_device(vdev); > struct ccw1 *ccw; > + int ret; > > ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw)); > if (!ccw) > - return; > + return -ENOMEM; > > /* Zero status bits. */ > vcdev->dma_area->status = 0; > @@ -749,8 +750,10 @@ static void virtio_ccw_reset(struct virtio_device *vdev) > ccw->flags = 0; > ccw->count = 0; > ccw->cda = 0; > - ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_RESET); > + ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_RESET); > ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw)); > + > + return ret; > } > > static u64 virtio_ccw_get_features(struct virtio_device *vdev) > diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c > index 4b15c00c0a0a..ddbfd5b5f3bd 100644 > --- a/drivers/virtio/virtio.c > +++ b/drivers/virtio/virtio.c > @@ -338,7 +338,7 @@ int register_virtio_device(struct virtio_device *dev) > /* Assign a unique device index and hence name. */ > err = ida_simple_get(&virtio_index_ida, 0, 0, GFP_KERNEL); > if (err < 0) > - goto out; > + goto out_err; > > dev->index = err; > dev_set_name(&dev->dev, "virtio%u", dev->index); > @@ -349,7 +349,9 @@ int register_virtio_device(struct virtio_device *dev) > > /* We always start by resetting the device, in case a previous > * driver messed it up. This also tests that code path a little. */ > - dev->config->reset(dev); > + err = dev->config->reset(dev); > + if (err) > + goto out_ida; > > /* Acknowledge that we've seen the device. */ > virtio_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE); > @@ -362,10 +364,14 @@ int register_virtio_device(struct virtio_device *dev) > */ > err = device_add(&dev->dev); > if (err) > - ida_simple_remove(&virtio_index_ida, dev->index); > -out: > - if (err) > - virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED); > + goto out_ida; > + > + return 0; > + > +out_ida: > + ida_simple_remove(&virtio_index_ida, dev->index); > +out_err: > + virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED); > return err; > } > EXPORT_SYMBOL_GPL(register_virtio_device); > @@ -408,7 +414,9 @@ int virtio_device_restore(struct virtio_device *dev) > > /* We always start by resetting the device, in case a previous > * driver messed it up. */ > - dev->config->reset(dev); > + ret = dev->config->reset(dev); > + if (ret) > + goto err; > > /* Acknowledge that we've seen the device. */ > virtio_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE); > diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c > index 56128b9c46eb..12b8f048c48d 100644 > --- a/drivers/virtio/virtio_mmio.c > +++ b/drivers/virtio/virtio_mmio.c > @@ -256,12 +256,13 @@ static void vm_set_status(struct virtio_device *vdev, u8 status) > writel(status, vm_dev->base + VIRTIO_MMIO_STATUS); > } > > -static void vm_reset(struct virtio_device *vdev) > +static int vm_reset(struct virtio_device *vdev) > { > struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); > > /* 0 status means a reset. */ > writel(0, vm_dev->base + VIRTIO_MMIO_STATUS); > + return 0; > } > > > diff --git a/drivers/virtio/virtio_pci_legacy.c b/drivers/virtio/virtio_pci_legacy.c > index d62e9835aeec..0b5d95e3efa1 100644 > --- a/drivers/virtio/virtio_pci_legacy.c > +++ b/drivers/virtio/virtio_pci_legacy.c > @@ -89,7 +89,7 @@ static void vp_set_status(struct virtio_device *vdev, u8 status) > iowrite8(status, vp_dev->ioaddr + VIRTIO_PCI_STATUS); > } > > -static void vp_reset(struct virtio_device *vdev) > +static int vp_reset(struct virtio_device *vdev) > { > struct virtio_pci_device *vp_dev = to_vp_device(vdev); > /* 0 status means a reset. */ > @@ -99,6 +99,8 @@ static void vp_reset(struct virtio_device *vdev) > ioread8(vp_dev->ioaddr + VIRTIO_PCI_STATUS); > /* Flush pending VQ/configuration callbacks. */ > vp_synchronize_vectors(vdev); > + > + return 0; > } > > static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector) > diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c > index fbd4ebc00eb6..cc3412a96a17 100644 > --- a/drivers/virtio/virtio_pci_modern.c > +++ b/drivers/virtio/virtio_pci_modern.c > @@ -158,7 +158,7 @@ static void vp_set_status(struct virtio_device *vdev, u8 status) > vp_modern_set_status(&vp_dev->mdev, status); > } > > -static void vp_reset(struct virtio_device *vdev) > +static int vp_reset(struct virtio_device *vdev) > { > struct virtio_pci_device *vp_dev = to_vp_device(vdev); > struct virtio_pci_modern_device *mdev = &vp_dev->mdev; > @@ -174,6 +174,7 @@ static void vp_reset(struct virtio_device *vdev) > msleep(1); > /* Flush pending VQ/configuration callbacks. */ > vp_synchronize_vectors(vdev); > + return 0; > } > > static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector) > diff --git a/drivers/virtio/virtio_vdpa.c b/drivers/virtio/virtio_vdpa.c > index e28acf482e0c..5fd4e627a9b0 100644 > --- a/drivers/virtio/virtio_vdpa.c > +++ b/drivers/virtio/virtio_vdpa.c > @@ -97,11 +97,13 @@ static void virtio_vdpa_set_status(struct virtio_device *vdev, u8 status) > return ops->set_status(vdpa, status); > } > > -static void virtio_vdpa_reset(struct virtio_device *vdev) > +static int virtio_vdpa_reset(struct virtio_device *vdev) > { > struct vdpa_device *vdpa = vd_get_vdpa(vdev); > > vdpa_reset(vdpa); > + > + return 0; > } > > static bool virtio_vdpa_notify(struct virtqueue *vq) > diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h > index 8519b3ae5d52..d2b0f1699a75 100644 > --- a/include/linux/virtio_config.h > +++ b/include/linux/virtio_config.h > @@ -44,9 +44,10 @@ struct virtio_shm_region { > * status: the new status byte > * @reset: reset the device > * vdev: the virtio device > - * After this, status and feature negotiation must be done again > + * Upon success, status and feature negotiation must be done again > * Device must not be reset from its vq/config callbacks, or in > * parallel with being added/removed. > + * Returns 0 on success or error status. > * @find_vqs: find virtqueues and instantiate them. > * vdev: the virtio_device > * nvqs: the number of virtqueues to find > @@ -82,7 +83,7 @@ struct virtio_config_ops { > u32 (*generation)(struct virtio_device *vdev); > u8 (*get_status)(struct virtio_device *vdev); > void (*set_status)(struct virtio_device *vdev, u8 status); > - void (*reset)(struct virtio_device *vdev); > + int (*reset)(struct virtio_device *vdev); > int (*find_vqs)(struct virtio_device *, unsigned nvqs, > struct virtqueue *vqs[], vq_callback_t *callbacks[], > const char * const names[], const bool *ctx,