[v5,0/7] x86: improve assisted tlb flush and use it in guest mode

Message

Roger Pau Monné Feb. 19, 2020, 5:43 p.m. UTC

Hello,

The following series aims to improve the TLB flush times when running
nested Xen, and it's specially beneficial when running in shim mode.

Only the HAP guest TLB flush is improved, the shadow paging TLB flush is
left as-is, and can be improved later if there's interest.

For a reference on the performance improvement see patch #7, as it's a
huge increase which can benefit other guests using assisted TLB flushes,
and also the ones using the viridian TLB flush assist (ie: Windows).

All patches have at least one Reviewed-by or Acked-by tag, the only code
change vs v4 is a fix to extract the order from the flags field in patch
#7.

Thanks, Roger.

Roger Pau Monne (7):
  x86/hvm: allow ASID flush when v != current
  x86/paging: add TLB flush hooks
  x86/hap: improve hypervisor assisted guest TLB flush
  x86/tlb: introduce a flush guests TLB flag
  x86/tlb: allow disabling the TLB clock
  xen/guest: prepare hypervisor ops to use alternative calls
  x86/tlb: use Xen L0 assisted TLB flush when available

 xen/arch/x86/flushtlb.c                | 24 ++++++---
 xen/arch/x86/guest/hyperv/hyperv.c     |  2 +-
 xen/arch/x86/guest/hypervisor.c        | 51 ++++++++++--------
 xen/arch/x86/guest/xen/xen.c           |  8 ++-
 xen/arch/x86/hvm/asid.c                |  6 +--
 xen/arch/x86/hvm/hvm.c                 | 51 ++----------------
 xen/arch/x86/mm/hap/hap.c              | 52 +++++++++++++++++++
 xen/arch/x86/mm/shadow/common.c        | 71 +++++++++++++++++++++++---
 xen/arch/x86/mm/shadow/hvm.c           |  2 +-
 xen/arch/x86/mm/shadow/multi.c         | 16 +++---
 xen/arch/x86/smp.c                     | 11 ++++
 xen/include/asm-x86/flushtlb.h         | 19 ++++++-
 xen/include/asm-x86/guest/hypervisor.h | 17 ++++++
 xen/include/asm-x86/hap.h              |  3 ++
 xen/include/asm-x86/shadow.h           | 12 +++++
 15 files changed, 246 insertions(+), 99 deletions(-)