Re: [RFC RFT PATCH 0/4] Handle set_memory_XXcrypted() errors in hyperv

From: Edgecombe, Rick P
Date: Thu Mar 07 2024 - 14:12:37 EST


On Thu, 2024-03-07 at 17:11 +0000, Michael Kelley wrote:
> Using your patches plus the changes in my comments, I've
> done most of the testing described above. The normal
> paths work, and when I hack set_memory_encrypted()
> to fail, the error paths correctly did not free the memory.
> I checked both the ring buffer memory and the additional
> vmalloc memory allocated by the netvsc driver and the uio
> driver.  The memory status can be checked after-the-fact
> via /proc/vmmallocinfo and /proc/buddyinfo since these
> are mostly large allocations. As expected, the drivers
> output their own error messages after the failures to
> teardown the GPADLs.
>
> I did not test the vmbus_disconnect() path since that
> effectively kills the VM.
>
> I tested in a normal VM, and in an SEV-SNP VM.  I didn't
> specifically test in a TDX VM, but given that Hyper-V CoCo
> guests run with a paravisor, the guest sees the same thing
> either way.

Thanks Michael! How would you feel about reposting the patches with
your changes added? I think you have a very good handle on the part of
the problem I understand, and additionally much more familiarity with
these drivers.