Re: [RFC][PATCH v2 0/3] IVSHMEM version 2 device for QEMU

[Liang Yan]

On 1/7/20 9:36 AM, Jan Kiszka wrote:
> Overdue update of the ivshmem 2.0 device model as presented at [1].
> 
> Changes in v2:
>  - changed PCI device ID to Siemens-granted one,
>    adjusted PCI device revision to 0
>  - removed unused feature register from device
>  - addressed feedback on specification document
>  - rebased over master
> 
> This version is now fully in sync with the implementation for Jailhouse
> that is currently under review [2][3], UIO and virtio-ivshmem drivers
> are shared. Jailhouse will very likely pick up this revision of the
> device in order to move forward with stressing it.
> 
> More details on the usage with QEMU were in the original cover letter
> (with adjustements to the new device ID):
> 
> If you want to play with this, the basic setup of the shared memory
> device is described in patch 1 and 3. UIO driver and also the
> virtio-ivshmem prototype can be found at
> 
>     http://git.kiszka.org/?p=linux.git;a=shortlog;h=refs/heads/queues/ivshmem2
> 
> Accessing the device via UIO is trivial enough. If you want to use it
> for virtio, this is additionally to the description in patch 3 needed on
> the virtio console backend side:
> 
>     modprobe uio_ivshmem
>     echo "110a 4106 1af4 1100 ffc003 ffffff" > 
> /sys/bus/pci/drivers/uio_ivshmem/new_id
>     linux/tools/virtio/virtio-ivshmem-console /dev/uio0
> 
> And for virtio block:
> 
>     echo "110a 4106 1af4 1100 ffc002 ffffff" > 
> /sys/bus/pci/drivers/uio_ivshmem/new_id
>     linux/tools/virtio/virtio-ivshmem-console /dev/uio0 /path/to/disk.img
> 
> After that, you can start the QEMU frontend instance with the
> virtio-ivshmem driver installed which can use the new /dev/hvc* or
> /dev/vda* as usual.
> 
Hi, Jan,

Nice work.

I did a full test for your this new version. QEMU device part looks
good, virtio console worked as expected. Just had some issue with
virtio-ivshmem-block tests here.

I suppose you mean "linux/tools/virtio/virtio-ivshmem-block"?

Noticed "ffc002" is the main difference, however I saw nothing response
when run echo command here, are there anything I need to prepare?

I build the driver in guest kernel already.

Do I need a new protocol or anything for below command line?
ivshmem2-server -F -l 64K -n 2 -V 3 -P 0x8003

Best,
Liang



> Any feedback welcome!
> 
> Jan
> 
> PS: Let me know if I missed someone potentially interested in this topic
> on CC - or if you would like to be dropped from the list.
> 
> [1] https://kvmforum2019.sched.com/event/TmxI
> [2] https://groups.google.com/forum/#!topic/jailhouse-dev/ffnCcRh8LOs
> [3] https://groups.google.com/forum/#!topic/jailhouse-dev/HX-0AGF1cjg
> 
> Jan Kiszka (3):
>   hw/misc: Add implementation of ivshmem revision 2 device
>   docs/specs: Add specification of ivshmem device revision 2
>   contrib: Add server for ivshmem revision 2
> 
>  Makefile                                  |    3 +
>  Makefile.objs                             |    1 +
>  configure                                 |    1 +
>  contrib/ivshmem2-server/Makefile.objs     |    1 +
>  contrib/ivshmem2-server/ivshmem2-server.c |  462 ++++++++++++
>  contrib/ivshmem2-server/ivshmem2-server.h |  158 +++++
>  contrib/ivshmem2-server/main.c            |  313 +++++++++
>  docs/specs/ivshmem-2-device-spec.md       |  376 ++++++++++
>  hw/misc/Makefile.objs                     |    2 +-
>  hw/misc/ivshmem2.c                        | 1085 
> +++++++++++++++++++++++++++++
>  include/hw/misc/ivshmem2.h                |   48 ++
>  include/hw/pci/pci_ids.h                  |    2 +
>  12 files changed, 2451 insertions(+), 1 deletion(-)
>  create mode 100644 contrib/ivshmem2-server/Makefile.objs
>  create mode 100644 contrib/ivshmem2-server/ivshmem2-server.c
>  create mode 100644 contrib/ivshmem2-server/ivshmem2-server.h
>  create mode 100644 contrib/ivshmem2-server/main.c
>  create mode 100644 docs/specs/ivshmem-2-device-spec.md
>  create mode 100644 hw/misc/ivshmem2.c
>  create mode 100644 include/hw/misc/ivshmem2.h
>