On Mon, Sep 1, 2025 at 4:40 PM Eugenio Perez Martin <epere...@redhat.com> wrote: > > On Mon, Sep 1, 2025 at 3:59 AM Jason Wang <jasow...@redhat.com> wrote: > > > > On Tue, Aug 26, 2025 at 7:27 PM Eugenio Pérez <epere...@redhat.com> wrote: > > > > > > This allows sepparate the different virtqueues in groups that shares the > > > 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 <epere...@redhat.com> > > > --- > > > 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 | 51 ++++++++++++++++++++++++++++-- > > > include/uapi/linux/vduse.h | 21 +++++++++++- > > > 2 files changed, 68 insertions(+), 4 deletions(-) > > > > > > diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c > > > b/drivers/vdpa/vdpa_user/vduse_dev.c > > > index e7bced0b5542..0f4e36dd167e 100644 > > > --- a/drivers/vdpa/vdpa_user/vduse_dev.c > > > +++ b/drivers/vdpa/vdpa_user/vduse_dev.c > > > @@ -58,6 +58,7 @@ 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; > > > @@ -114,6 +115,7 @@ 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; > > > @@ -592,6 +594,13 @@ 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); > > > + > > > + return dev->vqs[idx]->vq_group; > > > +} > > > + > > > static int vduse_vdpa_get_vq_state(struct vdpa_device *vdpa, u16 idx, > > > struct vdpa_vq_state *state) > > > { > > > @@ -678,6 +687,28 @@ static u8 vduse_vdpa_get_status(struct vdpa_device > > > *vdpa) > > > return dev->status; > > > } > > > > > > +static int vduse_fill_vq_groups(struct vduse_dev *dev) > > > +{ > > > + /* All vqs and descs must be in vq group 0 if ngroups < 2 */ > > > + if (dev->ngroups < 2) > > > + return 0; > > > + > > > + for (int i = 0; i < dev->vdev->vdpa.nvqs; ++i) { > > > + struct vduse_dev_msg msg = { 0 }; > > > + int ret; > > > + > > > + msg.req.type = VDUSE_GET_VQ_GROUP; > > > + msg.req.vq_group.index = i; > > > + ret = vduse_dev_msg_sync(dev, &msg); > > > + if (ret) > > > + return ret; > > > + > > > + dev->vqs[i]->vq_group = msg.resp.vq_group.group; > > > + } > > > + > > > + return 0; > > > +} > > > + > > > static void vduse_vdpa_set_status(struct vdpa_device *vdpa, u8 status) > > > { > > > struct vduse_dev *dev = vdpa_to_vduse(vdpa); > > > @@ -685,6 +716,11 @@ static void vduse_vdpa_set_status(struct vdpa_device > > > *vdpa, u8 status) > > > if (vduse_dev_set_status(dev, status)) > > > return; > > > > > > + if (((dev->status ^ status) & VIRTIO_CONFIG_S_FEATURES_OK) && > > > + (status & VIRTIO_CONFIG_S_FEATURES_OK)) > > > + if (vduse_fill_vq_groups(dev)) > > > + return; > > > > I may lose some context but I think we've agreed that we need to > > extend the status response for this instead of having multiple > > indepdent response. > > > > My understanding was it is ok to start with this version by [1]. We > can even make it asynchronous on top if we find this is a bottleneck > and the VDUSE device would need no change, would that work? > > > > + > > > dev->status = status; > > > } > > > > > > @@ -789,6 +825,7 @@ 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, > > > @@ -1737,12 +1774,19 @@ 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 > > > > 0xffff) > > > + return false; > > > > Let's use a macro instead of magic number. > > > > The rest of the limits are hardcoded, but I'm ok with changing this. > Is UINT16_MAX ok here, or do you prefer something like MAX_NGROUPS and > MAX_ASID?
MAX_NGROUPS and MAX_ASID seem to be better. Thanks > > [...] > > [1] > https://patchew.org/linux/20250807115752.1663383-1-epere...@redhat.com/20250807115752.1663383-3-epere...@redhat.com/#cacgkmeuvnggjgpzxnajipc+pcbt+dr6jqkrqr8ocx7hk1w3...@mail.gmail.com >