From: Si-Wei Liu Date: Wed, 18 Oct 2023 17:14:42 +0000 (+0300) Subject: vhost-vdpa: introduce descriptor group backend feature X-Git-Tag: v6.7-rc1~54^2~31 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=7db0d6027e69f47431800b510192436563ba415b;p=thirdparty%2Fkernel%2Flinux.git vhost-vdpa: introduce descriptor group backend feature Userspace knows if the device has dedicated descriptor group or not by checking this feature bit. It's only exposed if the vdpa driver backend implements the .get_vq_desc_group() operation callback. Userspace trying to negotiate this feature when it or the dependent _F_IOTLB_ASID feature hasn't been exposed will result in an error. Signed-off-by: Si-Wei Liu Acked-by: Eugenio Pérez Acked-by: Jason Wang Message-Id: <20231018171456.1624030-5-dtatulea@nvidia.com> Signed-off-by: Michael S. Tsirkin Reviewed-by: Si-Wei Liu Tested-by: Si-Wei Liu Tested-by: Lei Yang --- diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c index 78379ffd23363..2f21798a37ee0 100644 --- a/drivers/vhost/vdpa.c +++ b/drivers/vhost/vdpa.c @@ -389,6 +389,14 @@ static bool vhost_vdpa_can_resume(const struct vhost_vdpa *v) return ops->resume; } +static bool vhost_vdpa_has_desc_group(const struct vhost_vdpa *v) +{ + struct vdpa_device *vdpa = v->vdpa; + const struct vdpa_config_ops *ops = vdpa->config; + + return ops->get_vq_desc_group; +} + static long vhost_vdpa_get_features(struct vhost_vdpa *v, u64 __user *featurep) { struct vdpa_device *vdpa = v->vdpa; @@ -690,6 +698,7 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep, if (copy_from_user(&features, featurep, sizeof(features))) return -EFAULT; if (features & ~(VHOST_VDPA_BACKEND_FEATURES | + BIT_ULL(VHOST_BACKEND_F_DESC_ASID) | BIT_ULL(VHOST_BACKEND_F_SUSPEND) | BIT_ULL(VHOST_BACKEND_F_RESUME) | BIT_ULL(VHOST_BACKEND_F_ENABLE_AFTER_DRIVER_OK))) @@ -700,6 +709,12 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep, if ((features & BIT_ULL(VHOST_BACKEND_F_RESUME)) && !vhost_vdpa_can_resume(v)) return -EOPNOTSUPP; + if ((features & BIT_ULL(VHOST_BACKEND_F_DESC_ASID)) && + !(features & BIT_ULL(VHOST_BACKEND_F_IOTLB_ASID))) + return -EINVAL; + if ((features & BIT_ULL(VHOST_BACKEND_F_DESC_ASID)) && + !vhost_vdpa_has_desc_group(v)) + return -EOPNOTSUPP; vhost_set_backend_features(&v->vdev, features); return 0; } @@ -753,6 +768,8 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep, features |= BIT_ULL(VHOST_BACKEND_F_SUSPEND); if (vhost_vdpa_can_resume(v)) features |= BIT_ULL(VHOST_BACKEND_F_RESUME); + if (vhost_vdpa_has_desc_group(v)) + features |= BIT_ULL(VHOST_BACKEND_F_DESC_ASID); features |= vhost_vdpa_get_backend_features(v); if (copy_to_user(featurep, &features, sizeof(features))) r = -EFAULT; diff --git a/include/uapi/linux/vhost_types.h b/include/uapi/linux/vhost_types.h index 2d827d22cd99d..18ad6ae7ab5c6 100644 --- a/include/uapi/linux/vhost_types.h +++ b/include/uapi/linux/vhost_types.h @@ -185,5 +185,10 @@ struct vhost_vdpa_iova_range { * DRIVER_OK */ #define VHOST_BACKEND_F_ENABLE_AFTER_DRIVER_OK 0x6 +/* Device may expose the virtqueue's descriptor area, driver area and + * device area to a different group for ASID binding than where its + * buffers may reside. Requires VHOST_BACKEND_F_IOTLB_ASID. + */ +#define VHOST_BACKEND_F_DESC_ASID 0x7 #endif