Fine, however Red Hat would also need a way to test ivshmem code, with
proper quality assurance (that also benefits upstream, of course). With
ivshmem this is not possible without the out-of-tree packages.
You did not reply to my question: how to get the list of things that
are/will be disabled by Redhat?
About Redhat's QA, I do not care.
About Qemu's QA, I do care ;)
I guess we can combine both. What's about something like:
tests/virtio-net-test.c # qtest_add_func( is a nop)
but for ivshmem
test/ivshmem-test.c
?
would it have any values?
If not, what do you use at Redhat to test Qemu?
now, you cannot compare vhost-user to DPDK/ivshmem; both should exsit
because they have different scope and use cases. It is like comparing
two different(A) models of IPC:
I do repeat this use case that you had removed because vhost-user does
not solve it yet:
>> - ivshmem -> framework to be generic to have shared memory for many
>> use cases (HPC, in-memory-database, a network too like memnic).
- vhost-user -> networking use case specific
Not necessarily. First and foremost, vhost-user defines an API for
communication between QEMU and the host, including:
* file descriptor passing for the shared memory file
* mapping offsets in shared memory to physical memory addresses in the
guests
* passing dirty memory information back and forth, so that migration is
not prevented
* sending interrupts to a device
* setting up ring buffers in the shared memory
Yes, I do agree that it is promising.
And of course some tests are here:
https://lists.gnu.org/archive/html/qemu-devel/2014-03/msg00584.html
for some of the bullets you are listing (not all yet).
Also, vhost-user is documented! See here:
https://lists.gnu.org/archive/html/qemu-devel/2014-03/msg00581.html
as I told you, we'll send a contribution with ivshmem's documentation.
The only part of ivshmem that vhost doesn't include is the n-way
inter-guest doorbell. This is the part that requires a server and uio
driver. vhost only supports host->guest and guest->host doorbells.
agree: both will need it: vhost and ivshmem requires a doorbell for
VM2VM, but then we'll have a security issue to be managed by Qemu for
vhost and ivshmem.
I'll be pleased to contribute on it for ivshmem thru another thread that
this one.
ivhsmem does not require DPDK kernel driver. see memnic's PMD:
http://dpdk.org/browse/memnic/tree/pmd/pmd_memnic.c
You're right, I was confusing memnic and the vhost example in DPDK.
Definitively, it proves a lack of documentation. You welcome. Olivier
did explain it:
ivhsmem does not require hugetlbfs. It is optional.
> * it doesn't require ivshmem (it does require shared memory, which
> will also be added to 2.1)
Right, hugetlbfs is not required. A posix shared memory or tmpfs
can be used instead. For instance, to use /dev/shm/foobar:
qemu-system-x86_64 -enable-kvm -cpu host [...] \
-device ivshmem,size=16,shm=foobar
Best regards,
Vincent
_______________________________________________
Virtualization mailing list
Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
