Il 13/06/2014 15:41, Vincent JARDIN ha scritto:
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?
I don't know exactly what the answer is, and this is probably not the
right list to discuss it. I guess there are partnership programs with
Red Hat that I don't know the details of, but these are more for
management folks and not really for developers.
ivshmem in particular was disabled even in RHEL7 beta, so you could have
found out about this in December and opened a bug in Bugzilla about it.
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?
The first things to do are:
1) try to understand if there is any value in a simplified shared memory
device with no interrupts (and those no eventfd or uio dependencies, not
even optionally). You are not using them because DPDK only does polling
and basically reserves a core for the NIC code. If so, this would be a
very simple device, just a 100 or so lines of code. We could get this
in upstream, and it would be likely enabled in RHEL too.
2) if not, get the server and uio driver merged into the QEMU tree, and
document the protocol in docs/specs/ivshmem_device_spec.txt. It doesn't
matter if the code comes from the Nahanni repository or from your own
implementation. Also start fixing bugs such as the ones that Markus
reported (removing all exit() invocations).
Writing testcases using the qtest framework would also be useful, but
first of all it is important to make ivshmem easier to use.
If not, what do you use at Redhat to test Qemu?
We do integration testing using autotest/virt-test (QEMU and KVM
developers for upstream use it too) and also some manual functional tests.
Contributing ivshmem tests to the virt-test would also be helpful in
demonstrating your interest in maintaining ivshmem. The repository and
documentation is at https://github.com/autotest/virt-test/ (a bit
Fedora-centric).
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).
Right, ivshmem is better for guest-to-guest. vhost-user is not
restricted to networking, but it is indeed more focused on
guest-to-host. ivshmem is usable for guest-to-host, but I would prefer
still some "hybrid" that uses vhost-like messages to pass the shared
memory fds to the external program.
Paolo
