Merge tag 'vfio-v6.7-rc1' of https://github.com/awilliam/linux-vfio

Pull VFIO updates from Alex Williamson:

 - Add support for "chunk mode" in the mlx5-vfio-pci variant driver,
   which allows both larger device image sizes for migration, beyond the
   previous 4GB limit, and also read-ahead support for improved
   migration performance (Yishai Hadas)

 - A new bus master control interface for the CDX bus driver where there
   is no in-band mechanism to toggle device DMA as there is through
   config space on PCI devices (Nipun Gupta)

 - Add explicit alignment directives to vfio data structures to reduce
   the chance of breaking 32-bit userspace. In most cases this is
   transparent and the remaining cases where data structures are padded
   work within the existing rules for extending data structures within
   vfio (Stefan Hajnoczi)

 - Resolve a bug in the cdx bus driver noted when compiled with clang
   where missing parenthesis result in the wrong operation (Nathan
   Chancellor)

 - Resolve errors reported by smatch for a function when dealing with
   invalid inputs (Alex Williamson)

 - Add migration support to the mtty vfio/mdev sample driver for testing
   and integration purposes, allowing CI of migration without specific
   hardware requirements. Also resolve many of the short- comings of
   this driver relative to implementation of the vfio interrupt ioctl
   along the way (Alex Williamson)

* tag 'vfio-v6.7-rc1' of https://github.com/awilliam/linux-vfio:
  vfio/mtty: Enable migration support
  vfio/mtty: Overhaul mtty interrupt handling
  vfio: Fix smatch errors in vfio_combine_iova_ranges()
  vfio/cdx: Add parentheses between bitwise AND expression and logical NOT
  vfio/mlx5: Activate the chunk mode functionality
  vfio/mlx5: Add support for READING in chunk mode
  vfio/mlx5: Add support for SAVING in chunk mode
  vfio/mlx5: Pre-allocate chunks for the STOP_COPY phase
  vfio/mlx5: Rename some stuff to match chunk mode
  vfio/mlx5: Enable querying state size which is > 4GB
  vfio/mlx5: Refactor the SAVE callback to activate a work only upon an error
  vfio/mlx5: Wake up the reader post of disabling the SAVING migration file
  vfio: use __aligned_u64 in struct vfio_device_ioeventfd
  vfio: use __aligned_u64 in struct vfio_device_gfx_plane_info
  vfio: trivially use __aligned_u64 for ioctl structs
  vfio-cdx: add bus mastering device feature support
  vfio: add bus master feature to device feature ioctl
  cdx: add support for bus mastering

drivers/cdx/cdx.c

@@ -182,6 +182,38 @@ cdx_match_id(const struct cdx_device_id *ids, struct cdx_device *dev)
 	return NULL;
 }
 
+int cdx_set_master(struct cdx_device *cdx_dev)
+{
+	struct cdx_controller *cdx = cdx_dev->cdx;
+	struct cdx_device_config dev_config;
+	int ret = -EOPNOTSUPP;
+
+	dev_config.type = CDX_DEV_BUS_MASTER_CONF;
+	dev_config.bus_master_enable = true;
+	if (cdx->ops->dev_configure)
+		ret = cdx->ops->dev_configure(cdx, cdx_dev->bus_num,
+					      cdx_dev->dev_num, &dev_config);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(cdx_set_master);
+
+int cdx_clear_master(struct cdx_device *cdx_dev)
+{
+	struct cdx_controller *cdx = cdx_dev->cdx;
+	struct cdx_device_config dev_config;
+	int ret = -EOPNOTSUPP;
+
+	dev_config.type = CDX_DEV_BUS_MASTER_CONF;
+	dev_config.bus_master_enable = false;
+	if (cdx->ops->dev_configure)
+		ret = cdx->ops->dev_configure(cdx, cdx_dev->bus_num,
+					      cdx_dev->dev_num, &dev_config);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(cdx_clear_master);
+
 /**
  * cdx_bus_match - device to driver matching callback
  * @dev: the cdx device to match against

drivers/cdx/controller/cdx_controller.c

@@ -56,6 +56,10 @@ static int cdx_configure_device(struct cdx_controller *cdx,
 	case CDX_DEV_RESET_CONF:
 		ret = cdx_mcdi_reset_device(cdx->priv, bus_num, dev_num);
 		break;
+	case CDX_DEV_BUS_MASTER_CONF:
+		ret = cdx_mcdi_bus_master_enable(cdx->priv, bus_num, dev_num,
+						 dev_config->bus_master_enable);
+		break;
 	default:
 		ret = -EINVAL;
 	}

drivers/cdx/controller/mcdi_functions.c

@@ -137,3 +137,61 @@ int cdx_mcdi_reset_device(struct cdx_mcdi *cdx, u8 bus_num, u8 dev_num)
 
 	return ret;
 }
+
+static int cdx_mcdi_ctrl_flag_get(struct cdx_mcdi *cdx, u8 bus_num,
+				  u8 dev_num, u32 *flags)
+{
+	MCDI_DECLARE_BUF(inbuf, MC_CMD_CDX_DEVICE_CONTROL_GET_IN_LEN);
+	MCDI_DECLARE_BUF(outbuf, MC_CMD_CDX_DEVICE_CONTROL_GET_OUT_LEN);
+	size_t outlen;
+	int ret;
+
+	MCDI_SET_DWORD(inbuf, CDX_DEVICE_CONTROL_GET_IN_BUS, bus_num);
+	MCDI_SET_DWORD(inbuf, CDX_DEVICE_CONTROL_GET_IN_DEVICE, dev_num);
+	ret = cdx_mcdi_rpc(cdx, MC_CMD_CDX_DEVICE_CONTROL_GET, inbuf,
+			   sizeof(inbuf), outbuf, sizeof(outbuf), &outlen);
+	if (ret)
+		return ret;
+
+	if (outlen != MC_CMD_CDX_DEVICE_CONTROL_GET_OUT_LEN)
+		return -EIO;
+
+	*flags = MCDI_DWORD(outbuf, CDX_DEVICE_CONTROL_GET_OUT_FLAGS);
+
+	return 0;
+}
+
+static int cdx_mcdi_ctrl_flag_set(struct cdx_mcdi *cdx, u8 bus_num,
+				  u8 dev_num, bool enable, int bit_pos)
+{
+	MCDI_DECLARE_BUF(inbuf, MC_CMD_CDX_DEVICE_CONTROL_SET_IN_LEN);
+	u32 flags;
+	int ret;
+
+	/*
+	 * Get flags and then set/reset bit at bit_pos according to
+	 * the input params.
+	 */
+	ret = cdx_mcdi_ctrl_flag_get(cdx, bus_num, dev_num, &flags);
+	if (ret)
+		return ret;
+
+	flags = flags & (u32)(~(BIT(bit_pos)));
+	if (enable)
+		flags |= (1 << bit_pos);
+
+	MCDI_SET_DWORD(inbuf, CDX_DEVICE_CONTROL_SET_IN_BUS, bus_num);
+	MCDI_SET_DWORD(inbuf, CDX_DEVICE_CONTROL_SET_IN_DEVICE, dev_num);
+	MCDI_SET_DWORD(inbuf, CDX_DEVICE_CONTROL_SET_IN_FLAGS, flags);
+	ret = cdx_mcdi_rpc(cdx, MC_CMD_CDX_DEVICE_CONTROL_SET, inbuf,
+			   sizeof(inbuf), NULL, 0, NULL);
+
+	return ret;
+}
+
+int cdx_mcdi_bus_master_enable(struct cdx_mcdi *cdx, u8 bus_num,
+			       u8 dev_num, bool enable)
+{
+	return cdx_mcdi_ctrl_flag_set(cdx, bus_num, dev_num, enable,
+			MC_CMD_CDX_DEVICE_CONTROL_SET_IN_BUS_MASTER_ENABLE_LBN);
+}

drivers/cdx/controller/mcdi_functions.h

@@ -58,4 +58,17 @@ int cdx_mcdi_get_dev_config(struct cdx_mcdi *cdx,
 int cdx_mcdi_reset_device(struct cdx_mcdi *cdx,
 			  u8 bus_num, u8 dev_num);
 
+/**
+ * cdx_mcdi_bus_master_enable - Set/Reset bus mastering for cdx device
+ *				represented by bus_num:dev_num
+ * @cdx: pointer to MCDI interface.
+ * @bus_num: Bus number.
+ * @dev_num: Device number.
+ * @enable: Enable bus mastering if set, disable otherwise.
+ *
+ * Return: 0 on success, <0 on failure
+ */
+int cdx_mcdi_bus_master_enable(struct cdx_mcdi *cdx, u8 bus_num,
+			       u8 dev_num, bool enable);
+
 #endif /* CDX_MCDI_FUNCTIONS_H */

drivers/gpu/drm/i915/gvt/kvmgt.c

@@ -1379,7 +1379,7 @@ static long intel_vgpu_ioctl(struct vfio_device *vfio_dev, unsigned int cmd,
 		intel_gvt_reset_vgpu(vgpu);
 		return 0;
 	} else if (cmd == VFIO_DEVICE_QUERY_GFX_PLANE) {
-		struct vfio_device_gfx_plane_info dmabuf;
+		struct vfio_device_gfx_plane_info dmabuf = {};
 		int ret = 0;
 
 		minsz = offsetofend(struct vfio_device_gfx_plane_info,

drivers/vfio/cdx/main.c

@@ -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,

drivers/vfio/cdx/private.h

@@ -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 */