From: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
To: <linux-arm-kernel@lists.infradead.org>,
<kvmarm@lists.cs.columbia.edu>, <linux-kernel@vger.kernel.org>
Cc: <maz@kernel.org>, <will@kernel.org>, <catalin.marinas@arm.com>,
<james.morse@arm.com>, <julien.thierry.kdev@gmail.com>,
<suzuki.poulose@arm.com>, <jean-philippe@linaro.org>,
<julien@xen.org>, <linuxarm@huawei.com>
Subject: [PATCH v4 00/16] kvm/arm: Align the VMID allocation with the arm64 ASID one
Date: Wed, 14 Apr 2021 12:22:56 +0100 [thread overview]
Message-ID: <20210414112312.13704-1-shameerali.kolothum.thodi@huawei.com> (raw)
Hi,
This is an attempt to revive this series originally posted by
Julien Grall[1]. The main motive to work on this now is because
of the requirement to have Pinned KVM VMIDs and the RFC discussion
for the same basically suggested[2] to have a common/better vmid
allocator for KVM which this series provides.
Major Changes from v3:
-Changes related to Pinned ASID support.
-Changes to take care KPTI related bits reservation.
-Dropped support for 32 bit KVM.
-Rebase to 5.12-rc7
Individual patches have change history for any major changes
from v3.
Tests were performed on a HiSilicon D06 platform and so far not observed
any regressions.
For ASID allocation,
Avg of 10 runs(hackbench -s 512 -l 200 -g 300 -f 25 -P),
5.12-rc7: Time:18.8119
5.12-rc7+v4: Time: 18.459
~1.8% improvement.
For KVM VMID,
The measurement was made with maxcpus set to 8 and with the
number of VMID limited to 4-bit. The test involves running
concurrently 40 guests with 2 vCPUs. Each guest will then
execute hackbench 5 times before exiting.
The performance difference between the current algo and the
new one are(ag. of 10 runs):
- 1.9% less exit from the guest
- 0.7% faster
For complete series, please see,
https://github.com/hisilicon/kernel-dev/tree/private-v5.12-rc7-asid-v4
Please take a look and let me know your feedback.
Thanks,
Shameer
[1].https://patchwork.kernel.org/project/linux-arm-kernel/cover/20190724162534.7390-1-julien.grall@arm.com/
[2].https://lore.kernel.org/linux-arm-kernel/20210222155338.26132-6-shameerali.kolothum.thodi@huawei.com/T/#mff3129997739e2747172f4a2e81fd66be91ffea4
--------
From V3:
--------
Hi all,
This patch series is moving out the ASID allocator in a separate file in order
to re-use it for the VMID. The benefits are:
- CPUs are not forced to exit on a roll-over.
- Context invalidation is now per-CPU rather than
broadcasted.
There are no performance regression on the fastpath for ASID allocation.
Actually on the hackbench measurement (300 hackbench) it was .7% faster.
The measurement was made on a Seattle based SoC (8 CPUs), with the
number of VMID limited to 4-bit. The test involves running concurrently 40
guests with 2 vCPUs. Each guest will then execute hackbench 5 times
before exiting.
The performance difference (on 5.1-rc1) between the current algo and the
new one are:
- 2.5% less exit from the guest
- 22.4% more flush, although they are now local rather than broadcasted
- 0.11% faster (just for the record)
The ASID allocator rework to make it generic has been divided in multiple
patches to make the review easier.
A branch with the patch based on 5.3-rc1 can be found:
http://xenbits.xen.org/gitweb/?p=people/julieng/linux-arm.git;a=shortlog;h=refs/heads/vmid-rework/v3
For all the changes see in each patch.
Best regards,
Julien Grall (13):
arm64/mm: Introduce asid_info structure and move
asid_generation/asid_map to it
arm64/mm: Move active_asids and reserved_asids to asid_info
arm64/mm: Move bits to asid_info
arm64/mm: Move the variable lock and tlb_flush_pending to asid_info
arm64/mm: Remove dependency on MM in new_context
arm64/mm: Introduce NUM_CTXT_ASIDS
arm64/mm: Split asid_inits in 2 parts
arm64/mm: Split the function check_and_switch_context in 3 parts
arm64/mm: Introduce a callback to flush the local context
arm64: Move the ASID allocator code in a separate file
arm64/lib: Add an helper to free memory allocated by the ASID
allocator
arch/arm64: Introduce a capability to tell whether 16-bit VMID is
available
kvm/arm: Align the VMID allocation with the arm64 ASID one
Shameer Kolothum (3):
arm64/mm: Move Pinned ASID related variables to asid_info
arm64/mm: Split the arm64_mm_context_get/put
arm64/mm: Introduce a callback to set reserved bits
arch/arm64/include/asm/cpucaps.h | 3 +-
arch/arm64/include/asm/kvm_asm.h | 4 +-
arch/arm64/include/asm/kvm_host.h | 5 +-
arch/arm64/include/asm/kvm_mmu.h | 7 +-
arch/arm64/include/asm/lib_asid.h | 87 +++++++++
arch/arm64/kernel/cpufeature.c | 9 +
arch/arm64/kvm/arm.c | 124 +++++--------
arch/arm64/kvm/hyp/nvhe/hyp-main.c | 6 +-
arch/arm64/kvm/hyp/nvhe/tlb.c | 10 +-
arch/arm64/kvm/hyp/vhe/tlb.c | 10 +-
arch/arm64/kvm/mmu.c | 1 -
arch/arm64/lib/Makefile | 2 +
arch/arm64/lib/asid.c | 264 +++++++++++++++++++++++++++
arch/arm64/mm/context.c | 283 ++++-------------------------
14 files changed, 469 insertions(+), 346 deletions(-)
create mode 100644 arch/arm64/include/asm/lib_asid.h
create mode 100644 arch/arm64/lib/asid.c
--
2.17.1
next reply other threads:[~2021-04-14 11:24 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-14 11:22 Shameer Kolothum [this message]
2021-04-14 11:22 ` [PATCH v4 01/16] arm64/mm: Introduce asid_info structure and move asid_generation/asid_map to it Shameer Kolothum
2021-04-14 11:22 ` [PATCH v4 02/16] arm64/mm: Move active_asids and reserved_asids to asid_info Shameer Kolothum
2021-04-14 11:22 ` [PATCH v4 03/16] arm64/mm: Move bits " Shameer Kolothum
2021-04-14 11:23 ` [PATCH v4 04/16] arm64/mm: Move the variable lock and tlb_flush_pending " Shameer Kolothum
2021-04-14 11:23 ` [PATCH v4 05/16] arm64/mm: Remove dependency on MM in new_context Shameer Kolothum
2021-04-14 11:23 ` [PATCH v4 06/16] arm64/mm: Introduce NUM_CTXT_ASIDS Shameer Kolothum
2021-04-14 11:23 ` [PATCH v4 07/16] arm64/mm: Move Pinned ASID related variables to asid_info Shameer Kolothum
2021-04-14 11:23 ` [PATCH v4 08/16] arm64/mm: Split asid_inits in 2 parts Shameer Kolothum
2021-04-14 11:23 ` [PATCH v4 09/16] arm64/mm: Split the function check_and_switch_context in 3 parts Shameer Kolothum
2021-04-14 11:23 ` [PATCH v4 10/16] arm64/mm: Split the arm64_mm_context_get/put Shameer Kolothum
2021-04-14 11:23 ` [PATCH v4 11/16] arm64/mm: Introduce a callback to flush the local context Shameer Kolothum
2021-04-14 11:23 ` [PATCH v4 12/16] arm64/mm: Introduce a callback to set reserved bits Shameer Kolothum
2021-04-14 11:23 ` [PATCH v4 13/16] arm64: Move the ASID allocator code in a separate file Shameer Kolothum
2021-04-14 11:23 ` [PATCH v4 14/16] arm64/lib: Add an helper to free memory allocated by the ASID allocator Shameer Kolothum
2021-04-14 11:23 ` [PATCH v4 15/16] arch/arm64: Introduce a capability to tell whether 16-bit VMID is available Shameer Kolothum
2021-04-14 11:23 ` [PATCH v4 16/16] kvm/arm: Align the VMID allocation with the arm64 ASID one Shameer Kolothum
2021-04-22 16:08 ` [PATCH v4 00/16] " Will Deacon
2021-04-23 8:31 ` Shameerali Kolothum Thodi
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210414112312.13704-1-shameerali.kolothum.thodi@huawei.com \
--to=shameerali.kolothum.thodi@huawei.com \
--cc=catalin.marinas@arm.com \
--cc=james.morse@arm.com \
--cc=jean-philippe@linaro.org \
--cc=julien.thierry.kdev@gmail.com \
--cc=julien@xen.org \
--cc=kvmarm@lists.cs.columbia.edu \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linuxarm@huawei.com \
--cc=maz@kernel.org \
--cc=suzuki.poulose@arm.com \
--cc=will@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).