On Fri, Jun 26, 2020 at 01:42:27PM +0000, Wei Liu wrote:

On Thu, Jun 25, 2020 at 11:37:20AM -0400, Andres Beltran wrote:

quoted

From: Andres Beltran (Microsoft) <redacted>

Currently, VMbus drivers use pointers into guest memory as request IDs
for interactions with Hyper-V. To be more robust in the face of errors
or malicious behavior from a compromised Hyper-V, avoid exposing
guest memory addresses to Hyper-V. Also avoid Hyper-V giving back a
bad request ID that is then treated as the address of a guest data
structure with no validation. Instead, encapsulate these memory
addresses and provide small integers as request IDs.

The first patch creates the definitions for the data structure, provides
helper methods to generate new IDs and retrieve data, and
allocates/frees the memory needed for vmbus_requestor.

The second and third patches make use of vmbus_requestor to send request
IDs to Hyper-V in storvsc and netvsc respectively.

Per my understanding, this new data structure is per-channel, so it
won't introduce contention on the lock in multi-queue scenario. Have you
done any testing to confirm there is no severe performance regression?

I did run some performance tests using our dev pipeline (storage and
network workloads).  I did not find regressions w.r.t. baseline.

  Andrea