[Xen-devel] [PATCH v2 0/3] Xen on Hyper-V: Implement L0 assisted TLB flush

[Wei Liu <wl@xen.org>]

Hi all

This seris is based on Roger's L0 assisted flush series.

I have done some testing against a Linux on Hyper-V in a 32-vcpu VM.
All builds were done with -j32.



Building Xen on Linux:
real    0m45.376s
user    2m28.156s
sys     0m51.672s

Building Xen on Linux on Xen on Hyper-V, no assisted flush:
real    3m8.762s
user    10m46.787s
sys     30m14.492s

Building Xen on Linux on Xen on Hyper-V, with assisted flush:
real    0m44.369s
user    3m16.231s
sys     3m3.330s



Building Linux x86_64_defconfig on Linux:
real    0m59.698s
user    21m14.014s
sys     2m58.742s

Building Linux x86_64_defconfig on Linux on Xen on Hyper-V, no assisted
flush:
real    2m6.284s
user    31m18.706s
sys     20m31.106s

Building Linux x86_64_defconfig on Linux on Xen on Hyper-V, with assisted
flush:
real    1m38.968s
user    28m40.398s
sys     11m20.151s



There are various degrees of improvement depending on the workload. Xen
can perhaps be optmised a bit more because it currently doesn't pass the
address space id (cr3) to Hyper-V, but that requires reworking TLB flush
APIs within Xen.

Wei.

Cc: Jan Beulich <jbeulich@suse.com>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Wei Liu <wl@xen.org>
Cc: Roger Pau Monné <roger.pau@citrix.com>
Cc: Michael Kelley <mikelley@microsoft.com>
Cc: Paul Durrant <pdurrant@amazon.com>

Wei Liu (3):
  x86/hypervisor: pass flags to hypervisor_flush_tlb
  x86/hyperv: skeleton for L0 assisted TLB flush
  x86/hyperv: L0 assisted TLB flush

 xen/arch/x86/guest/hyperv/Makefile     |   2 +
 xen/arch/x86/guest/hyperv/hyperv.c     |  17 ++
 xen/arch/x86/guest/hyperv/private.h    |  13 ++
 xen/arch/x86/guest/hyperv/tlb.c        | 211 +++++++++++++++++++++++++
 xen/arch/x86/guest/hyperv/util.c       |  74 +++++++++
 xen/arch/x86/guest/hypervisor.c        |   7 +-
 xen/arch/x86/guest/xen/xen.c           |   2 +-
 xen/arch/x86/smp.c                     |   5 +-
 xen/include/asm-x86/flushtlb.h         |   3 +
 xen/include/asm-x86/guest/hypervisor.h |  10 +-
 10 files changed, 333 insertions(+), 11 deletions(-)
 create mode 100644 xen/arch/x86/guest/hyperv/tlb.c
 create mode 100644 xen/arch/x86/guest/hyperv/util.c

-- 
2.20.1


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