Albert Esteve <aest...@redhat.com> writes: > On Tue, Aug 19, 2025 at 12:42 PM Stefan Hajnoczi <stefa...@redhat.com> wrote: >> >> On Mon, Aug 18, 2025 at 12:03:51PM +0200, Albert Esteve wrote: >> > Improve vhost-user-test to properly validate >> > VHOST_USER_GET_SHMEM_CONFIG message handling by >> > directly simulating the message exchange. >> > >> > The test manually triggers the >> > VHOST_USER_GET_SHMEM_CONFIG message by calling >> > chr_read() with a crafted VhostUserMsg, allowing direct >> > validation of the shmem configuration response handler. >> >> It looks like this test case invokes its own chr_read() function without >> going through QEMU, so I don't understand what this is testing? > > I spent some time trying to test it, but in the end I could not > instatiate vhost-user-device because it is non user_creatable. I did > not find any test for vhost-user-device anywhere else either. But I > had already added most of the infrastructure here so I fallback to > chr_read() communication to avoid having to delete everything. My > though was that once we have other devices that use shared memory, > they could tweak the test to instantiate the proper device and test > this and the map/unmap operations. > > Although after writing this, I think other devices will actually a > specific layout for their shared memory. So > VHOST_USER_GET_SHMEM_CONFIG is only ever going to be used by > vhost-user-device.
FWIW: I'm not so sure — my non-upstream Cloud Hypervisor frontend for the crosvm vhost-user GPU device[1] uses the equivalent of VHOST_USER_GET_SHMEM_CONFIG to allow the backend to choose the size of the shared memory region, and I could imagine that being something other devices might want to do too? [1]: https://spectrum-os.org/software/cloud-hypervisor/ > In general, trying to test this patch series has been a headache other > than trying with external device code I have. If you have an idea that > I could try to test this, I can try. Otherwise, probably is best to > remove this commit from the series and wait for another vhost-user > device that uses map/unmap to land to be able to test it.
signature.asc
Description: PGP signature
