Re: [Qemu-devel] vhost-user memory regions.

[Naredula Janardhana Reddy]

Yes, vhost-user need a fix in qemu related to memory regions.

Is there any Plans to implement in Multi-queue for vhost-user?.

Thanks

Jana

On 17 July 2015 at 17:25, Marc-André Lureau <address@hidden> wrote:

Hi Naredula

On Mon, Jul 13, 2015 at 10:35 AM, Naredula Janardhana Reddy
<address@hidden> wrote:
>
> In the QEMU 2.3.0 , The memory regions published to user space application
> is limited address space, not the complete memory regions of quest vm, due
> to this , the user level app cannot decode all the memory block addresses.
> This is needed for reading the packet from virtio ring.
>
> Is there any configuration  in qemu to overcome the above  or it is bug in
> virtio-user?.
>
> Test details:
> Qemu cmd line:
>     /opt/qemu.2.3.0/bin/qemu-system-x86_64 -enable-kvm -gdb
> tcp::1336,server,nowait
> -monitor tcp::51008,server,nowait,nodelay -m 256M -mem-path /hugetlbfs
> -mem-prealloc
> -smp 2 -chardev backend=socket,id=ch1,path=/opt_src/port1 -netdev
> vhost-user,id=guest0,chardev=ch1 -device
> virtio-net-pci,mac=00:30:48:DB:5E:01,netdev=guest0,mq=on,vectors=8 -vnc :8
> -serial telnet::50008,server,nowait -daemonize -append
> net_send_int_disable=1 ipaddr=192.168.122.3 gw=192.168.122.1 nic_intr_off=1
> netbh_tightloop=0 page_cache=1  -kernel /opt_src/jiny/jiny_image.bin -drive
> if=virtio,id=hdr0,file=/opt_src/jiny/disk
> In the below message
>
> The below is message recevied at the user level application from
> vhost-user(qemu), the size is only 655k.  but needed is 256M(size of  memory
> or shared memory size of hugetlb).  I have Temporarly hardcoded the size in
> the app by changing the size to 256M from 655K. so that network packet
> address can able to decode from  the virtio ring.
>
> Cmd: VHOST_USER_SET_MEM_TABLE (0x5)
> flags: 0x1
> regions: 2
> region:
>         gpa = 0x0
>         size = 655360
>         ua = 0x2aaaaac00000
> region:
>         gpa = 0x0
>         size = 786432
>         ua = 0xff40000
>

I got a similar error when using vapp
(https://github.com/virtualopensystems/vapp), it's missing mmap_offset
field.
You need this fix: https://github.com/virtualopensystems/vapp/pull/3/files

--
Marc-André Lureau