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From: Roger Pau Monne <roger.pau@citrix.com>
To: <xen-devel@lists.xenproject.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>,
	Paul Durrant <paul@xen.org>, Wei Liu <wl@xen.org>,
	Jan Beulich <jbeulich@suse.com>,
	Roger Pau Monne <roger.pau@citrix.com>
Subject: [Xen-devel] [PATCH v2 0/3] x86: improve assisted tlb flush and use it in guest mode
Date: Fri, 10 Jan 2020 17:04:01 +0100	[thread overview]
Message-ID: <20200110160404.15573-1-roger.pau@citrix.com> (raw)

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.

Patch #2 is likely the most controversial one, as it changes the
implementation of assisted TLB flushes. I have to admit I haven't been
able to figure out why HVM guest context flushes issued a
flush_tlb_mask, and the commit introducing such behavior doesn't contain
a helpful commit message.

See patch #3 for a comparison on the performance of the L0 assisted
flush vs using x2APIC shorthand.

Thanks, Roger.

Roger Pau Monne (3):
  x86/hvm: allow ASID flush when v != current
  x86/hvm: rework HVMOP_flush_tlbs
  x86/tlb: use Xen L0 assisted TLB flush when available

 xen/arch/x86/guest/hypervisor.c        |  9 +++++
 xen/arch/x86/guest/xen/xen.c           |  6 +++
 xen/arch/x86/hvm/asid.c                |  6 +--
 xen/arch/x86/hvm/hvm.c                 | 54 +++++++++++---------------
 xen/arch/x86/hvm/viridian/viridian.c   |  7 +---
 xen/arch/x86/smp.c                     |  6 +++
 xen/include/asm-x86/guest/hypervisor.h | 13 +++++++
 xen/include/asm-x86/hvm/hvm.h          |  2 +-
 8 files changed, 62 insertions(+), 41 deletions(-)

-- 
2.24.1


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             reply	other threads:[~2020-01-10 16:04 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-10 16:04 Roger Pau Monne [this message]
2020-01-10 16:04 ` [Xen-devel] [PATCH v2 1/3] x86/hvm: allow ASID flush when v != current Roger Pau Monne
2020-01-10 16:04 ` [Xen-devel] [PATCH v2 2/3] x86/hvm: rework HVMOP_flush_tlbs Roger Pau Monne
2020-01-10 16:04 ` [Xen-devel] [PATCH v2 3/3] x86/tlb: use Xen L0 assisted TLB flush when available Roger Pau Monne
2020-01-10 16:08 ` [Xen-devel] [PATCH v2 0/3] x86: improve assisted tlb flush and use it in guest mode Jan Beulich
2020-01-10 16:14   ` Roger Pau Monné

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