Re: [dpdk-dev] Issues with example/vhost with running VM

["Xie, Huawei" <huawei.xie@intel.com>]

Try --socket-mem or -m 2048 to limit the vhost switch's memory consumption, note that vswitch requires several GB memory due to some issue in the example, so try allocating more huges pages.

> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Maciej Grochowski
> Sent: Wednesday, May 13, 2015 11:00 PM
> To: dev@dpdk.org
> Subject: [dpdk-dev] Issues with example/vhost with running VM
> 
> Hello, I trying to create vm2vm benchmark on my ubuntu(14.04) based
> platform.
> 
> I had compiled DPDK to run a vhost example app with followed flags
> 
> CONFIG_RTE_LIBRTE_VHOST=y
> CONFIG_RTE_LIBRTE_VHOST_USER=y
> CONFIG_RTE_LIBRTE_VHOST_DEBUG=n
> 
> 
> then I run vhost app based on documentation:
> 
> ./build/app/vhost-switch -c f -n 4 --huge-dir /mnt/huge -- -p 0x1
> --dev-basename usvhost
> 
> then I trying to start kvm VM
> 
> kvm -nographic -boot c -machine pc-i440fx-1.4,accel=kvm -name vm1 -cpu
> host
> -smp 2 -mem-path /mnt/huge -mem-prealloc \
> -hda /home/ubuntu/qemu/debian_squeeze2_amd64.qcow2 -m 4096  \
> -chardev
> socket,id=char1,path=/home/ubuntu/dpdk/examples/vhost/usvhost \
> -netdev type=vhost-user,id=hostnet1,chardev=char1 \
> -device
> virtio-net-
> pci,netdev=hostnet1,id=net1,csum=off,gso=off,guest_tso4=off,guest_tso6=o
> ff,guest_ecn=off
> \
> -chardev
> socket,id=char2,path=/home/ubuntu/dpdk/examples/vhost/usvhost \
> -netdev type=vhost-user,id=hostnet2,chardev=char2 \
> -device
> virtio-net-
> pci,netdev=hostnet2,id=net2,csum=off,gso=off,guest_tso4=off,guest_tso6=o
> ff,guest_ecn=off
> 
> but this give me an error:
> 
> qemu-system-x86_64: -netdev type=vhost-user,id=hostnet1,chardev=char1:
> chardev "char1" went up
> qemu-system-x86_64: unable to map backing store for hugepages: Cannot
> allocate memory
> 
> 
> On vhost app in logs I can see:
> 
> VHOST_DATA: Procesing on Core 1 started
> VHOST_DATA: Procesing on Core 2 started
> VHOST_DATA: Procesing on Core 3 started
> VHOST_CONFIG: socket created, fd:25
> VHOST_CONFIG: bind to usvhost
> VHOST_CONFIG: new virtio connection is 26
> VHOST_CONFIG: new device, handle is 0
> VHOST_CONFIG: read message VHOST_USER_SET_OWNER
> VHOST_CONFIG: read message VHOST_USER_GET_FEATURES
> VHOST_CONFIG: read message VHOST_USER_SET_VRING_CALL
> VHOST_CONFIG: vring call idx:0 file:27
> VHOST_CONFIG: read message VHOST_USER_SET_VRING_CALL
> VHOST_CONFIG: vring call idx:1 file:28
> VHOST_CONFIG: recvmsg failed
> VHOST_CONFIG: vhost peer closed
> 
> 
> So that looks at huge page memory problem.
> On my machine I had 2048k huge pages, and I can allocate 2479.
> 
> before I run vhost "cat /proc/meminfo | grep Huge" show
> 
> AnonHugePages:      4096 kB
> HugePages_Total:    2479
> HugePages_Free:     2479
> HugePages_Rsvd:        0
> HugePages_Surp:        0
> Hugepagesize:       2048 kB
> 
> and while running vhost:
> 
> AnonHugePages:      4096 kB
> HugePages_Total:    2479
> HugePages_Free:        0
> HugePages_Rsvd:        0
> HugePages_Surp:        0
> Hugepagesize:       2048 kB
> 
> so that looks that I didn't have free hugepages for my VM. But this looks
> as independently if I reserve 1k 2k or 2.5k memory always example/vhost got
> whole memory.
> 
> Any help will be greatly appreciated