Commit f869197b authored by Jim Harris's avatar Jim Harris Committed by Tomasz Zawadzki
Browse files

virtio: assert and ERRLOG for virtio-user dynamic mem allocations 



We do not support dynamic memory allocation with the virtio-user
library - it results in SET_MEM_TABLE vhost messages for every
change which is not supported by the vhost target.

Add '-s 256' to vhost fuzz script, to ensure it does not
violate the new restriction.

This is a follow-on patch for issue #2596.

Signed-off-by: default avatarJim Harris <james.r.harris@intel.com>
Change-Id: If851f53d7d670ac8443f0d9c8f4e3cbe82e0df7c
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/14249


Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: default avatarDong Yi <yidong0635@126.com>
Reviewed-by: default avatarChangpeng Liu <changpeng.liu@intel.com>
Reviewed-by: default avatarShuhei Matsumoto <smatsumoto@nvidia.com>
Reviewed-by: default avatarAleksey Marchuk <alexeymar@nvidia.com>
parent 9ffb0497

CHANGELOG.md

+10 −0
Original line number Diff line number Diff line
@@ -85,6 +85,16 @@ AEN. 


Added new functions: `spdk_hexlify` and `spdk_unhexlify`.



### virtio



virtio-vhost-user no longer tries to support dynamic memory allocation.  The vhost target does

not support the high rate of SET_MEM_TABLE vhost messages that result from dynamic memory

allocation, so a virtio-vhost-user device will now present an ERRLOG, assert, and skip the

SET_MEM_TABLE vhost message if a memory notification is received outside of the normal device

start/stop. Applications using the virtio library in vhost-user mode should now pre-allocate

the application's memory using the -s/--mem-size option and use single shared memory file

segments using the -g/--single-file-segments option.



## v22.05



### sock

lib/virtio/virtio_vhost_user.c

+14 −0
Original line number Diff line number Diff line
@@ -29,6 +29,7 @@ struct virtio_user_dev { 
	uint32_t	queue_size;



	uint8_t		status;

	bool		is_stopping;

	char		path[PATH_MAX];

	uint64_t	protocol_features;

	struct vring	vrings[SPDK_VIRTIO_MAX_VIRTQUEUES];
@@ -586,6 +587,18 @@ virtio_user_map_notify(void *cb_ctx, struct spdk_mem_map *map, 
	uint64_t features;

	int ret;



	/* We do not support dynamic memory allocation with virtio-user.  If this is the

	 * initial notification when the device is started, dev->mem_map will be NULL.  If

	 * this is the final notification when the device is stopped, dev->is_stopping will

	 * be true.  All other cases are unsupported.

	 */

	if (dev->mem_map != NULL && !dev->is_stopping) {

		assert(false);

		SPDK_ERRLOG("Memory map change with active virtio_user_devs not allowed.\n");

		SPDK_ERRLOG("Pre-allocate memory for application using -s (mem_size) option.\n");

		return -1;

	}



	/* We have to resend all mappings anyway, so don't bother with any

	 * page tracking.

	 */
@@ -626,6 +639,7 @@ virtio_user_unregister_mem(struct virtio_dev *vdev) 
{

	struct virtio_user_dev *dev = vdev->ctx;



	dev->is_stopping = true;

	spdk_mem_map_free(&dev->mem_map);

}

test/vhost/fuzz/fuzz.sh

+1 −1
Original line number Diff line number Diff line
@@ -7,7 +7,7 @@ source "$rootdir/scripts/common.sh" 


VHOST_APP+=(-p 0)

FUZZ_RPC_SOCK="/var/tmp/spdk_fuzz.sock"

VHOST_FUZZ_APP+=(-r "$FUZZ_RPC_SOCK" -g --wait-for-rpc)

VHOST_FUZZ_APP+=(-r "$FUZZ_RPC_SOCK" -g -s 256 --wait-for-rpc)



vhost_rpc_py="$rootdir/scripts/rpc.py"

fuzz_generic_rpc_py="$rootdir/scripts/rpc.py -s $FUZZ_RPC_SOCK"