drivers: hv: dxgkrnl: Share objects with the host

Implement the LX_DXSHAREOBJECTWITHHOST ioctl.
This ioctl is used to create a Windows NT handle on the host
for the given shared object (resource or sync object). The NT
handle is returned to the caller. The caller could share the NT
handle with a host application, which needs to access the object.
The host application can open the shared resource using the NT
handle. This way the guest and the host have access to the same
object.

Fix incorrect handling of error results from copy_from_user().

Signed-off-by: Iouri Tarassov <iourit@linux.microsoft.com>
[kms: forward port to 6.6 from 6.1. No code changes made.]
Signed-off-by: Kelsey Steele <kelseysteele@microsoft.com>

Author: Iouri Tarassov

drivers/hv/dxgkrnl/dxgkrnl.h

@@ -872,6 +872,8 @@ int dxgvmb_send_get_stdalloc_data(struct dxgdevice *device,
 int dxgvmb_send_async_msg(struct dxgvmbuschannel *channel,
 			  void *command,
 			  u32 cmd_size);
+int dxgvmb_send_share_object_with_host(struct dxgprocess *process,
+				struct d3dkmt_shareobjectwithhost *args);
 
 void signal_host_cpu_event(struct dxghostevent *eventhdr);
 int ntstatus2int(struct ntstatus status);

drivers/hv/dxgkrnl/dxgvmbus.c

@@ -881,6 +881,50 @@ int dxgvmb_send_destroy_sync_object(struct dxgprocess *process,
 	return ret;
 }
 
+int dxgvmb_send_share_object_with_host(struct dxgprocess *process,
+				struct d3dkmt_shareobjectwithhost *args)
+{
+	struct dxgkvmb_command_shareobjectwithhost *command;
+	struct dxgkvmb_command_shareobjectwithhost_return result = {};
+	int ret;
+	struct dxgvmbusmsg msg = {.hdr = NULL};
+
+	ret = init_message(&msg, NULL, process, sizeof(*command));
+	if (ret)
+		return ret;
+	command = (void *)msg.msg;
+
+	ret = dxgglobal_acquire_channel_lock();
+	if (ret < 0)
+		goto cleanup;
+
+	command_vm_to_host_init2(&command->hdr,
+				 DXGK_VMBCOMMAND_SHAREOBJECTWITHHOST,
+				 process->host_handle);
+	command->device_handle = args->device_handle;
+	command->object_handle = args->object_handle;
+
+	ret = dxgvmb_send_sync_msg(dxgglobal_get_dxgvmbuschannel(),
+				   msg.hdr, msg.size, &result, sizeof(result));
+
+	dxgglobal_release_channel_lock();
+
+	if (ret || !NT_SUCCESS(result.status)) {
+		if (ret == 0)
+			ret = ntstatus2int(result.status);
+		DXG_ERR("Host failed to share object with host: %d %x",
+			ret, result.status.v);
+		goto cleanup;
+	}
+	args->object_vail_nt_handle = result.vail_nt_handle;
+
+cleanup:
+	free_message(&msg, process);
+	if (ret)
+		DXG_ERR("err: %d", ret);
+	return ret;
+}
+
 /*
  * Virtual GPU messages to the host
  */
@@ -2323,37 +2367,43 @@ int dxgvmb_send_create_hwqueue(struct dxgprocess *process,
 
 	ret = copy_to_user(&inargs->queue, &command->hwqueue,
 			   sizeof(struct d3dkmthandle));
-	if (ret < 0) {
+	if (ret) {
 		DXG_ERR("failed to copy hwqueue handle");
+		ret = -EINVAL;
 		goto cleanup;
 	}
 	ret = copy_to_user(&inargs->queue_progress_fence,
 			   &command->hwqueue_progress_fence,
 			   sizeof(struct d3dkmthandle));
-	if (ret < 0) {
+	if (ret) {
 		DXG_ERR("failed to progress fence");
+		ret = -EINVAL;
 		goto cleanup;
 	}
 	ret = copy_to_user(&inargs->queue_progress_fence_cpu_va,
 			   &hwqueue->progress_fence_mapped_address,
 			   sizeof(inargs->queue_progress_fence_cpu_va));
-	if (ret < 0) {
+	if (ret) {
 		DXG_ERR("failed to copy fence cpu va");
+		ret = -EINVAL;
 		goto cleanup;
 	}
 	ret = copy_to_user(&inargs->queue_progress_fence_gpu_va,
 			   &command->hwqueue_progress_fence_gpuva,
 			   sizeof(u64));
-	if (ret < 0) {
+	if (ret) {
 		DXG_ERR("failed to copy fence gpu va");
+		ret = -EINVAL;
 		goto cleanup;
 	}
 	if (args->priv_drv_data_size) {
 		ret = copy_to_user(args->priv_drv_data,
 				   command->priv_drv_data,
 				   args->priv_drv_data_size);
-		if (ret < 0)
+		if (ret) {
 			DXG_ERR("failed to copy private data");
+			ret = -EINVAL;
+		}
 	}
 
 cleanup:

drivers/hv/dxgkrnl/dxgvmbus.h

@@ -574,4 +574,22 @@ struct dxgkvmb_command_destroyhwqueue {
 	struct d3dkmthandle		hwqueue;
 };
 
+struct dxgkvmb_command_shareobjectwithhost {
+	struct dxgkvmb_command_vm_to_host hdr;
+	struct d3dkmthandle	device_handle;
+	struct d3dkmthandle	object_handle;
+	u64			reserved;
+};
+
+struct dxgkvmb_command_shareobjectwithhost_return {
+	struct ntstatus	status;
+	u32		alignment;
+	u64		vail_nt_handle;
+};
+
+int
+dxgvmb_send_sync_msg(struct dxgvmbuschannel *channel,
+		     void *command, u32 command_size, void *result,
+		     u32 result_size);
+
 #endif /* _DXGVMBUS_H */

drivers/hv/dxgkrnl/ioctl.c

@@ -2460,6 +2460,7 @@ dxgkio_open_sync_object_nt(struct dxgprocess *process, void *__user inargs)
 	if (ret == 0)
 		goto success;
 	DXG_ERR("failed to copy output args");
+	ret = -EINVAL;
 
 cleanup:
 
@@ -3364,8 +3365,10 @@ dxgkio_share_objects(struct dxgprocess *process, void *__user inargs)
 	tmp = (u64) object_fd;
 
 	ret = copy_to_user(args.shared_handle, &tmp, sizeof(u64));
-	if (ret < 0)
+	if (ret) {
 		DXG_ERR("failed to copy shared handle");
+		ret = -EINVAL;
+	}
 
 cleanup:
 	if (ret < 0) {
@@ -3773,6 +3776,37 @@ dxgkio_open_resource_nt(struct dxgprocess *process,
 	return ret;
 }
 
+static int
+dxgkio_share_object_with_host(struct dxgprocess *process, void *__user inargs)
+{
+	struct d3dkmt_shareobjectwithhost args;
+	int ret;
+
+	ret = copy_from_user(&args, inargs, sizeof(args));
+	if (ret) {
+		DXG_ERR("failed to copy input args");
+		ret = -EINVAL;
+		goto cleanup;
+	}
+
+	ret = dxgvmb_send_share_object_with_host(process, &args);
+	if (ret) {
+		DXG_ERR("dxgvmb_send_share_object_with_host dailed");
+		goto cleanup;
+	}
+
+	ret = copy_to_user(inargs, &args, sizeof(args));
+	if (ret) {
+		DXG_ERR("failed to copy data to user");
+		ret = -EINVAL;
+	}
+
+cleanup:
+
+	DXG_TRACE("ioctl:%s %d", errorstr(ret), ret);
+	return ret;
+}
+
 static struct ioctl_desc ioctls[] = {
 /* 0x00 */	{},
 /* 0x01 */	{dxgkio_open_adapter_from_luid, LX_DXOPENADAPTERFROMLUID},
@@ -3850,7 +3884,7 @@ static struct ioctl_desc ioctls[] = {
 		 LX_DXQUERYRESOURCEINFOFROMNTHANDLE},
 /* 0x42 */	{dxgkio_open_resource_nt, LX_DXOPENRESOURCEFROMNTHANDLE},
 /* 0x43 */	{},
-/* 0x44 */	{},
+/* 0x44 */	{dxgkio_share_object_with_host, LX_DXSHAREOBJECTWITHHOST},
 /* 0x45 */	{},
 };
 

include/uapi/misc/d3dkmthk.h

@@ -952,6 +952,13 @@ struct d3dkmt_enumadapters3 {
 #endif
 };
 
+struct d3dkmt_shareobjectwithhost {
+	struct d3dkmthandle	device_handle;
+	struct d3dkmthandle	object_handle;
+	__u64			reserved;
+	__u64			object_vail_nt_handle;
+};
+
 /*
  * Dxgkrnl Graphics Port Driver ioctl definitions
  *
@@ -1021,5 +1028,7 @@ struct d3dkmt_enumadapters3 {
 	_IOWR(0x47, 0x41, struct d3dkmt_queryresourceinfofromnthandle)
 #define LX_DXOPENRESOURCEFROMNTHANDLE	\
 	_IOWR(0x47, 0x42, struct d3dkmt_openresourcefromnthandle)
+#define LX_DXSHAREOBJECTWITHHOST	\
+	_IOWR(0x47, 0x44, struct d3dkmt_shareobjectwithhost)
 
 #endif /* _D3DKMTHK_H */