Commit f325e71c authored by Jim Harris's avatar Jim Harris
Browse files

vhost: defer setting up new mem table 



First step is do not destroy an existing device in
vhost_user_set_mem_table().  This is because we may
still be processing I/O via INT13 while QEMU is setting
up the mem tables for OS boot.

The primary part of this patch though is to defer
using the new mem table until after we receive the
first SET_VRING_ADDR message.  SET_VRING_ADDR will be
sent by QEMU when guest OS virtio-scsi driver starts
initialization.  At this point it is safe to invalidate
the old mem tables because there will be no more
INT13 I/O at this point.

Signed-off-by: default avatarJim Harris <james.r.harris@intel.com>
Change-Id: I45fb5910f45e7fd2cf4a325341ad105a57d8ea40
parent 7fa7f91e

lib/vhost/rte_vhost/vhost.h

+4 −0
Original line number Diff line number Diff line
@@ -43,6 +43,7 @@ 
#include <rte_log.h>



#include "rte_virtio_net.h"

#include "vhost_user.h"



/* Used to indicate that the device is running on a data core */

#define VIRTIO_DEV_RUNNING 1
@@ -171,6 +172,9 @@ struct virtio_net { 
	uint32_t		nr_guest_pages;

	uint32_t		max_guest_pages;

	struct guest_page       *guest_pages;

	int			has_new_mem_table;

	struct VhostUserMemory	mem_table;

	int			mem_table_fds[VHOST_MEMORY_MAX_NREGIONS];

} __rte_cache_aligned;



/**

lib/vhost/rte_vhost/vhost_user.c

+33 −8
Original line number Diff line number Diff line
@@ -317,6 +317,8 @@ qva_to_vva(struct virtio_net *dev, uint64_t qva) 
	return 0;

}



static int vhost_setup_mem_table(struct virtio_net *dev);



/*

 * The virtio device sends us the desc, used and avail ring addresses.

 * This function then converts these to our address space.
@@ -326,6 +328,12 @@ vhost_user_set_vring_addr(struct virtio_net *dev, VhostUserMsg *msg) 
{

	struct vhost_virtqueue *vq;



	if (dev->has_new_mem_table) {

		vhost_setup_mem_table(dev);

		dev->has_new_mem_table = 0;

	}





	if (dev->mem == NULL)

		return -1;
@@ -492,7 +500,30 @@ dump_guest_pages(struct virtio_net *dev) 
static int

vhost_user_set_mem_table(struct virtio_net *dev, struct VhostUserMsg *pmsg)

{

	struct VhostUserMemory memory = pmsg->payload.memory;

	uint32_t i;



	if (dev->has_new_mem_table) {

		/*

		 * The previous mem table was not consumed, so close the

		 *  file descriptors from that mem table before copying

		 *  the new one.

		 */

		for (i = 0; i < dev->mem_table.nregions; i++) {

			close(dev->mem_table_fds[i]);

		}

	}



	memcpy(&dev->mem_table, &pmsg->payload.memory, sizeof(dev->mem_table));

	memcpy(dev->mem_table_fds, pmsg->fds, sizeof(dev->mem_table_fds));

	dev->has_new_mem_table = 1;



	return 0;

}



static int

vhost_setup_mem_table(struct virtio_net *dev)

{

	struct VhostUserMemory memory = dev->mem_table;

	struct virtio_memory_region *reg;

	void *mmap_addr;

	uint64_t mmap_size;
@@ -501,12 +532,6 @@ vhost_user_set_mem_table(struct virtio_net *dev, struct VhostUserMsg *pmsg) 
	uint32_t i;

	int fd;



	/* Remove from the data plane. */

	if (dev->flags & VIRTIO_DEV_RUNNING) {

		dev->flags &= ~VIRTIO_DEV_RUNNING;

		notify_ops->destroy_device(dev->vid);

	}



	if (dev->mem) {

		free_mem_region(dev);

		rte_free(dev->mem);
@@ -531,7 +556,7 @@ vhost_user_set_mem_table(struct virtio_net *dev, struct VhostUserMsg *pmsg) 
	dev->mem->nregions = memory.nregions;



	for (i = 0; i < memory.nregions; i++) {

		fd  = pmsg->fds[i];

		fd  = dev->mem_table_fds[i];

		reg = &dev->mem->regions[i];



		reg->guest_phys_addr = memory.regions[i].guest_phys_addr;