From 7db0d6027e69f47431800b510192436563ba415b Mon Sep 17 00:00:00 2001 From: Si-Wei Liu Date: Wed, 18 Oct 2023 20:14:42 +0300 Subject: vhost-vdpa: introduce descriptor group backend feature MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 --- drivers/vhost/vdpa.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'drivers/vhost') diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c index 78379ffd2336..2f21798a37ee 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; -- cgit