On Fri, Sep 26, 2025 at 12:14:29PM +0200, Eugenio Pérez wrote: > This allows sepparate the different virtqueues in groups that shares the
separate > same address space. Asking the VDUSE device for the groups of the vq at > the beginning as they're needed for the DMA API. > > Allocating 3 vq groups as net is the device that need the most groups: > * Dataplane (guest passthrough) > * CVQ > * Shadowed vrings. > > Future versions of the series can include dynamic allocation of the > groups array so VDUSE can declare more groups. > > Signed-off-by: Eugenio Pérez <[email protected]> > --- > v5: > * Revert core vdpa changes (Jason). > * Fix group == ngroup case in checking VQ_SETUP argument (Jason). > > v4: > * Revert the "invalid vq group" concept and assume 0 if not set (Jason). > * Make config->ngroups == 0 invalid (Jason). > > v3: > * Make the default group an invalid group as long as VDUSE device does > not set it to some valid u32 value. Modify the vdpa core to take that > into account (Jason). > * Create the VDUSE_DEV_MAX_GROUPS instead of using a magic number > > v2: > * Now the vq group is in vduse_vq_config struct instead of issuing one > VDUSE message per vq. > > v1: > * Fix: Remove BIT_ULL(VIRTIO_S_*), as _S_ is already the bit (Maxime) > > RFC v3: > * Increase VDUSE_MAX_VQ_GROUPS to 0xffff (Jason). It was set to a lower > value to reduce memory consumption, but vqs are already limited to > that value and userspace VDUSE is able to allocate that many vqs. > * Remove the descs vq group capability as it will not be used and we can > add it on top. > * Do not ask for vq groups in number of vq groups < 2. > * Move the valid vq groups range check to vduse_validate_config. > > RFC v2: > * Cache group information in kernel, as we need to provide the vq map > tokens properly. > * Add descs vq group to optimize SVQ forwarding and support indirect > descriptors out of the box. > --- > drivers/vdpa/vdpa_user/vduse_dev.c | 46 ++++++++++++++++++++++++++---- > include/uapi/linux/vduse.h | 12 ++++++-- > 2 files changed, 50 insertions(+), 8 deletions(-) > > diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c > b/drivers/vdpa/vdpa_user/vduse_dev.c > index 2b6a8958ffe0..99e37def7a83 100644 > --- a/drivers/vdpa/vdpa_user/vduse_dev.c > +++ b/drivers/vdpa/vdpa_user/vduse_dev.c > @@ -40,6 +40,7 @@ > #define DRV_LICENSE "GPL v2" > > #define VDUSE_DEV_MAX (1U << MINORBITS) > +#define VDUSE_DEV_MAX_GROUPS 0xffff > #define VDUSE_MAX_BOUNCE_SIZE (1024 * 1024 * 1024) > #define VDUSE_MIN_BOUNCE_SIZE (1024 * 1024) > #define VDUSE_BOUNCE_SIZE (64 * 1024 * 1024) > @@ -59,6 +60,7 @@ struct vduse_virtqueue { > struct vdpa_vq_state state; > bool ready; > bool kicked; > + u32 vq_group; > spinlock_t kick_lock; > spinlock_t irq_lock; > struct eventfd_ctx *kickfd; > @@ -115,6 +117,7 @@ struct vduse_dev { > u8 status; > u32 vq_num; > u32 vq_align; > + u32 ngroups; > struct vduse_umem *umem; > struct mutex mem_lock; > unsigned int bounce_size; > @@ -456,6 +459,7 @@ static void vduse_dev_reset(struct vduse_dev *dev) > vq->driver_addr = 0; > vq->device_addr = 0; > vq->num = 0; > + vq->vq_group = 0; > memset(&vq->state, 0, sizeof(vq->state)); > > spin_lock(&vq->kick_lock); > @@ -593,6 +597,16 @@ static int vduse_vdpa_set_vq_state(struct vdpa_device > *vdpa, u16 idx, > return 0; > } > > +static u32 vduse_get_vq_group(struct vdpa_device *vdpa, u16 idx) > +{ > + struct vduse_dev *dev = vdpa_to_vduse(vdpa); > + > + if (dev->api_version < VDUSE_API_VERSION_1) > + return 0; > + > + return dev->vqs[idx]->vq_group; > +} > + > static int vduse_vdpa_get_vq_state(struct vdpa_device *vdpa, u16 idx, > struct vdpa_vq_state *state) > { > @@ -790,6 +804,7 @@ static const struct vdpa_config_ops vduse_vdpa_config_ops > = { > .set_vq_cb = vduse_vdpa_set_vq_cb, > .set_vq_num = vduse_vdpa_set_vq_num, > .get_vq_size = vduse_vdpa_get_vq_size, > + .get_vq_group = vduse_get_vq_group, > .set_vq_ready = vduse_vdpa_set_vq_ready, > .get_vq_ready = vduse_vdpa_get_vq_ready, > .set_vq_state = vduse_vdpa_set_vq_state, > @@ -1253,12 +1268,24 @@ static long vduse_dev_ioctl(struct file *file, > unsigned int cmd, > if (config.index >= dev->vq_num) > break; > > - if (!is_mem_zero((const char *)config.reserved, > - sizeof(config.reserved))) > + if (dev->api_version < VDUSE_API_VERSION_1 && config.group) > + break; > + > + if (dev->api_version >= VDUSE_API_VERSION_1) { > + if (config.group >= dev->ngroups) > + break; > + if (dev->status & VIRTIO_CONFIG_S_DRIVER_OK) > + break; > + } > + > + if (config.reserved1 || > + !is_mem_zero((const char *)config.reserved2, > + sizeof(config.reserved2))) > break; > > index = array_index_nospec(config.index, dev->vq_num); > dev->vqs[index]->num_max = config.max_size; > + dev->vqs[index]->vq_group = config.group; > ret = 0; > break; > } > @@ -1738,12 +1765,20 @@ static bool features_is_valid(struct vduse_dev_config > *config) > return true; > } > > -static bool vduse_validate_config(struct vduse_dev_config *config) > +static bool vduse_validate_config(struct vduse_dev_config *config, > + u64 api_version) > { > if (!is_mem_zero((const char *)config->reserved, > sizeof(config->reserved))) > return false; > > + if (api_version < VDUSE_API_VERSION_1 && config->ngroups) > + return false; > + > + if (api_version >= VDUSE_API_VERSION_1 && > + (!config->ngroups || config->ngroups > VDUSE_DEV_MAX_GROUPS)) > + return false; > + > if (config->vq_align > PAGE_SIZE) > return false; > > @@ -1859,6 +1894,7 @@ static int vduse_create_dev(struct vduse_dev_config > *config, > dev->device_features = config->features; > dev->device_id = config->device_id; > dev->vendor_id = config->vendor_id; > + dev->ngroups = (dev->api_version < 1) ? 1 : config->ngroups; > dev->name = kstrdup(config->name, GFP_KERNEL); > if (!dev->name) > goto err_str; > @@ -1937,7 +1973,7 @@ static long vduse_ioctl(struct file *file, unsigned int > cmd, > break; > > ret = -EINVAL; > - if (vduse_validate_config(&config) == false) > + if (!vduse_validate_config(&config, control->api_version)) > break; > > buf = vmemdup_user(argp + size, config.config_size); > @@ -2018,7 +2054,7 @@ static int vduse_dev_init_vdpa(struct vduse_dev *dev, > const char *name) > > vdev = vdpa_alloc_device(struct vduse_vdpa, vdpa, dev->dev, > &vduse_vdpa_config_ops, &vduse_map_ops, > - 1, 1, name, true); > + dev->ngroups, 1, name, true); > if (IS_ERR(vdev)) > return PTR_ERR(vdev); > > diff --git a/include/uapi/linux/vduse.h b/include/uapi/linux/vduse.h > index ccb92a1efce0..a3d51cf6df3a 100644 > --- a/include/uapi/linux/vduse.h > +++ b/include/uapi/linux/vduse.h > @@ -31,6 +31,7 @@ > * @features: virtio features > * @vq_num: the number of virtqueues > * @vq_align: the allocation alignment of virtqueue's metadata > + * @ngroups: number of vq groups that VDUSE device declares > * @reserved: for future use, needs to be initialized to zero > * @config_size: the size of the configuration space > * @config: the buffer of the configuration space > @@ -45,7 +46,8 @@ struct vduse_dev_config { > __u64 features; > __u32 vq_num; > __u32 vq_align; > - __u32 reserved[13]; > + __u32 ngroups; /* if VDUSE_API_VERSION >= 1 */ > + __u32 reserved[12]; > __u32 config_size; > __u8 config[]; > }; > @@ -122,14 +124,18 @@ struct vduse_config_data { > * struct vduse_vq_config - basic configuration of a virtqueue > * @index: virtqueue index > * @max_size: the max size of virtqueue > - * @reserved: for future use, needs to be initialized to zero > + * @reserved1: for future use, needs to be initialized to zero > + * @group: virtqueue group > + * @reserved2: for future use, needs to be initialized to zero > * > * Structure used by VDUSE_VQ_SETUP ioctl to setup a virtqueue. > */ > struct vduse_vq_config { > __u32 index; > __u16 max_size; > - __u16 reserved[13]; > + __u16 reserved1; > + __u32 group; > + __u16 reserved2[10]; > }; > > /* > -- > 2.51.0
