On 1/11/2017 10:42 AM, Jason Wang wrote:
On 2017年01月10日 14:11, Tan, Jianfeng wrote:
Hi Jason,
On 1/9/2017 12:39 PM, Jason Wang wrote:
On 2016年12月23日 15:14, Jianfeng Tan wrote:
This patch add support vhost kernel as the backend for virtio_user.
Three main hook functions are added:
- vhost_kernel_setup() to open char device, each vq pair needs one
vhostfd;
- vhost_kernel_ioctl() to communicate control messages with vhost
kernel module;
- vhost_kernel_enable_queue_pair() to open tap device and set it
as the backend of corresonding vhost fd (that is to say, vq
pair).
Signed-off-by: Jianfeng Tan <jianfeng....@intel.com>
---
[...]
+/* TUNSETIFF ifr flags */
+#define IFF_TAP 0x0002
+#define IFF_NO_PI 0x1000
+#define IFF_ONE_QUEUE 0x2000
+#define IFF_VNET_HDR 0x4000
+#define IFF_MULTI_QUEUE 0x0100
+#define IFF_ATTACH_QUEUE 0x0200
+#define IFF_DETACH_QUEUE 0x0400
Do we really want to duplicate those things which has been exposed
by uapi here?
You mean those defined in <linux/if_tun.h>? Redefine those common
macros, or include standard header file, with respective pros and
cons. DPDK prefers the redefinition way as far as I understand,
doesn't it?
Well, if you really want to do this, you may want to use an
independent file. Then you can sync it with linux headers with a bash
script.
Agreed!
[...]
+static struct vhost_memory_kernel *
+prepare_vhost_memory_kernel(void)
+{
+ uint32_t i, j, k = 0;
+ struct rte_memseg *seg;
+ struct vhost_memory_region *mr;
+ struct vhost_memory_kernel *vm;
+
+ vm = malloc(sizeof(struct vhost_memory_kernel) +
+ VHOST_KERNEL_MAX_REGIONS *
+ sizeof(struct vhost_memory_region));
+
+ for (i = 0; i < RTE_MAX_MEMSEG; ++i) {
+ seg = &rte_eal_get_configuration()->mem_config->memseg[i];
+ if (!seg->addr)
+ break;
If we're sure the number of regions is less than 64(or the module
parameter read from /sys), can we avoid the iteration here?
The "if" statement under the "for" statement can save us from all
RTE_MAX_MEMSEG iteration.
But if we know the number of regions is short than the limit, there's
even no need for this?
The problem is: we don't have a variable to know how many segments are
there in DPDK. Anyway, we need to report error in the situation that #
of segments > # of regions. Or can you give a more specific example?
[...]
+ if (dev->ifname)
+ strncpy(ifr.ifr_name, dev->ifname, IFNAMSIZ);
+ else
+ strncpy(ifr.ifr_name, "tap%d", IFNAMSIZ);
+ if (ioctl(tapfd, TUNSETIFF, (void *)&ifr) == -1) {
+ PMD_DRV_LOG(ERR, "TUNSETIFF failed: %s", strerror(errno));
+ goto error;
+ }
This requires CAP_NET_ADMIN, so we should really consider to accept
a pre-created fd here.
It sounds like a future work for me. So far, all DPDK apps are
running in privileged mode (including CAP_NET_ADMIN?).
That's not safe.
Yes.
Accepting a per-created fd can solve this, and can even support macvtap
So you are proposing a way to specify the virtio_user parameter like,
--vdev=virtio_user,tapfd=fd1,xxx, right? As replied in your another
comment, it's a great way to go. But I'm afraid we have no time to
implement that in this cycle.
Thanks,
Jianfeng
