[v8,3/3] vfio-cdx: add bus mastering device feature support
Commit Message
Support Bus master enable and disable on VFIO-CDX devices using
VFIO_DEVICE_FEATURE_BUS_MASTER flag over VFIO_DEVICE_FEATURE IOCTL.
Co-developed-by: Shubham Rohila <shubham.rohila@amd.com>
Signed-off-by: Shubham Rohila <shubham.rohila@amd.com>
Signed-off-by: Nipun Gupta <nipun.gupta@amd.com>
---
Changes v7->v8:
- None
Changes v6->v7:
- Add check for BME in open, thus resulting in correct response
in feature probe.
- Set vdev_regions to NULL in case of error in vfio device open.
Changes v5->v6:
- Called CDX device reset at cdx_open_device()
Changes v4->v5:
- Use device feature IOCTL instead of adding a new VFIO IOCTL
for bus master feature.
Changes in v4:
- This patch is newly added which uses cdx_set_master() and
cdx_clear_master() APIs.
drivers/vfio/cdx/main.c | 57 +++++++++++++++++++++++++++++++++++++-
drivers/vfio/cdx/private.h | 2 ++
2 files changed, 58 insertions(+), 1 deletion(-)
@@ -14,7 +14,7 @@ static int vfio_cdx_open_device(struct vfio_device *core_vdev)
container_of(core_vdev, struct vfio_cdx_device, vdev);
struct cdx_device *cdx_dev = to_cdx_device(core_vdev->dev);
int count = cdx_dev->res_count;
- int i;
+ int i, ret;
vdev->regions = kcalloc(count, sizeof(struct vfio_cdx_region),
GFP_KERNEL_ACCOUNT);
@@ -39,6 +39,17 @@ static int vfio_cdx_open_device(struct vfio_device *core_vdev)
if (!(cdx_dev->res[i].flags & IORESOURCE_READONLY))
vdev->regions[i].flags |= VFIO_REGION_INFO_FLAG_WRITE;
}
+ ret = cdx_dev_reset(core_vdev->dev);
+ if (ret) {
+ kfree(vdev->regions);
+ vdev->regions = NULL;
+ return ret;
+ }
+ ret = cdx_clear_master(cdx_dev);
+ if (ret)
+ vdev->flags &= ~BME_SUPPORT;
+ else
+ vdev->flags |= BME_SUPPORT;
return 0;
}
@@ -52,6 +63,49 @@ static void vfio_cdx_close_device(struct vfio_device *core_vdev)
cdx_dev_reset(core_vdev->dev);
}
+static int vfio_cdx_bm_ctrl(struct vfio_device *core_vdev, u32 flags,
+ void __user *arg, size_t argsz)
+{
+ size_t minsz =
+ offsetofend(struct vfio_device_feature_bus_master, op);
+ struct vfio_cdx_device *vdev =
+ container_of(core_vdev, struct vfio_cdx_device, vdev);
+ struct cdx_device *cdx_dev = to_cdx_device(core_vdev->dev);
+ struct vfio_device_feature_bus_master ops;
+ int ret;
+
+ if (!vdev->flags & BME_SUPPORT)
+ return -ENOTTY;
+
+ ret = vfio_check_feature(flags, argsz, VFIO_DEVICE_FEATURE_SET,
+ sizeof(ops));
+ if (ret != 1)
+ return ret;
+
+ if (copy_from_user(&ops, arg, minsz))
+ return -EFAULT;
+
+ switch (ops.op) {
+ case VFIO_DEVICE_FEATURE_CLEAR_MASTER:
+ return cdx_clear_master(cdx_dev);
+ case VFIO_DEVICE_FEATURE_SET_MASTER:
+ return cdx_set_master(cdx_dev);
+ default:
+ return -EINVAL;
+ }
+}
+
+static int vfio_cdx_ioctl_feature(struct vfio_device *device, u32 flags,
+ void __user *arg, size_t argsz)
+{
+ switch (flags & VFIO_DEVICE_FEATURE_MASK) {
+ case VFIO_DEVICE_FEATURE_BUS_MASTER:
+ return vfio_cdx_bm_ctrl(device, flags, arg, argsz);
+ default:
+ return -ENOTTY;
+ }
+}
+
static int vfio_cdx_ioctl_get_info(struct vfio_cdx_device *vdev,
struct vfio_device_info __user *arg)
{
@@ -169,6 +223,7 @@ static const struct vfio_device_ops vfio_cdx_ops = {
.open_device = vfio_cdx_open_device,
.close_device = vfio_cdx_close_device,
.ioctl = vfio_cdx_ioctl,
+ .device_feature = vfio_cdx_ioctl_feature,
.mmap = vfio_cdx_mmap,
.bind_iommufd = vfio_iommufd_physical_bind,
.unbind_iommufd = vfio_iommufd_physical_unbind,
@@ -23,6 +23,8 @@ struct vfio_cdx_region {
struct vfio_cdx_device {
struct vfio_device vdev;
struct vfio_cdx_region *regions;
+ u32 flags;
+#define BME_SUPPORT BIT(0)
};
#endif /* VFIO_CDX_PRIVATE_H */