From: Stephen Hemminger <step...@networkplumber.org> Sent: Wednesday, July 22, 2020 11:41 AM > > On Wed, 22 Jul 2020 11:10:48 -0700 > "Andres Beltran" <lkmlab...@gmail.com> wrote: > > > 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. > > > > Thanks. > > Andres Beltran > > > > Cc: James E.J. Bottomley <j...@linux.ibm.com> > > Cc: Martin K. Petersen <martin.peter...@oracle.com> > > Cc: David S. Miller <da...@davemloft.net> > > > > 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 | 175 ++++++++++++++++++++++++++++++ > > drivers/net/hyperv/hyperv_net.h | 13 +++ > > drivers/net/hyperv/netvsc.c | 79 +++++++++++--- > > drivers/net/hyperv/rndis_filter.c | 1 + > > drivers/scsi/storvsc_drv.c | 85 +++++++++++++-- > > include/linux/hyperv.h | 22 ++++ > > 6 files changed, 350 insertions(+), 25 deletions(-) > > > > > What is the performance impact of this? > It means keeping a global (bookkeeping) structure which should have > noticeable impact on mult-queue performance.
The bookkeeping structure is per-VMbus channel. There's nothing global. Andrea Parri previously did some testing and reported no measurable impact. Michael
