Re: [PATCH 0/3] Drivers: hv: vmbus: vmbus_requestor data structure

[Wei Liu]

On Thu, Jun 25, 2020 at 11:37:20AM -0400, Andres Beltran wrote:
> From: Andres Beltran (Microsoft) <lkmlabelt@xxxxxxxxx>
> 
> 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?

Wei.

> Thanks.
> Andres Beltran
> 
> Cc: linux-scsi@xxxxxxxxxxxxxxx
> Cc: netdev@xxxxxxxxxxxxxxx
> Cc: "James E.J. Bottomley" <jejb@xxxxxxxxxxxxx>
> Cc: "Martin K. Petersen" <martin.petersen@xxxxxxxxxx>
> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
> 
> Andres Beltran (3):
>   Drivers: hv: vmbus: Add vmbus_requestor data structure for VMBus
>     hardening
>   scsi: storvsc: Use vmbus_requestor to generate transaction ids for
>     VMBus hardening
>   hv_netvsc: Use vmbus_requestor to generate transaction ids for VMBus
>     hardening
> 
>  drivers/hv/channel.c              | 150 ++++++++++++++++++++++++++++++
>  drivers/net/hyperv/hyperv_net.h   |  10 ++
>  drivers/net/hyperv/netvsc.c       |  56 +++++++++--
>  drivers/net/hyperv/rndis_filter.c |   1 +
>  drivers/scsi/storvsc_drv.c        |  62 ++++++++++--
>  include/linux/hyperv.h            |  22 +++++
>  6 files changed, 283 insertions(+), 18 deletions(-)
> 
> -- 
> 2.25.1
>