4 day week.
[TCWG-1424] Investigate profile feedback on codesize
Have now got all the data I need, started the process of tidying up
scripts to analyse whether it is worth posting upstream and what the
best default parameters are.
[Misc]
Track down problem on AArch64 build-bot to a likely code-gen problem
in Clang 3.8 for AArch64 only. Wrote a patch to use clang 6.0 on all
the Linaro buildbots rather than just the libcxx builder. Will
hopefully get deployed next week.
[LLD] Work on adding support for EF_ARM_ABI_FLOAT_HARD and EF_ARM_ABI_FLOAT_SOFT
Needed to unblock freebsd from moving onto trunk
Mostly done, just need to finish adding tests. Might be a good jumping
off point to implement full build attributes support.
SVE Support ([VIRT-198])
========================
- posted {PATCH} tcg/aarch64: limit mul_vec size Message-Id:
<20180719154248.29669-1-alex.bennee(a)linaro.org> : done
- finished preparing [talk for HPC workshop on 26th]
- delivered it Thursday evening, recording will go online in due
course
- blog post is now [live on linaro.org]
[VIRT-198] https://projects.linaro.org/browse/VIRT-198
[talk for HPC workshop on 26th]
https://docs.google.com/presentation/d/1Jz9ePpJ_YGd3vPXMj090VwRwPfBSYWHlSiz…
[live on linaro.org] https://www.linaro.org/blog/sve-in-qemu-linux-user/
Write and submit Connect abstract
- submitted abstract: My other machine is virtual for YVR18
SVE Reviews
- finished reviewing {RFC PATCH 00/16} KVM: arm64: Initial support for
SVE guests Message-Id:
<1529593060-542-1-git-send-email-Dave.Martin(a)arm.com>
QEMU ARMv8.3 Support ([VIRT-241])
=================================
- had a [quick run at VHE] which crystallised some of the issues with
register aliasing
- obviously need to sit and think about a design for this
[VIRT-241] https://projects.linaro.org/browse/VIRT-241
[ARMv8.1 Mandatory Features]
https://projects.linaro.org/browse/TCWG-1434
[ARMv8.1 optional features] https://projects.linaro.org/browse/TCWG-1435
[quick run at VHE] https://github.com/stsquad/qemu/tree/add-vhe-rfc
Upstream Work ([VIRT-109])
==========================
- posted {PATCH v1 for 3.0 0/2} fix for bug 1783362 Message-Id:
<20180726132947.28538-1-alex.bennee(a)linaro.org>
- started reviewing {PATCH v5 00/24} Fixing record/replay and adding
reverse debugging Message-Id:
<20180725121311.12867.21729.stgit@pasha-VirtualBox>
- number of build issues need to be resolved
[VIRT-109] https://projects.linaro.org/browse/VIRT-109
[v2 of docker fixes]
https://github.com/stsquad/qemu/tree/testing/docker-fixes-for-3.0-v2
[debootstrap master]
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=903657
Testing and CI
==============
- finish converting the CI RISU jobs to submit via qa-reports :todo
- got a Packet.net machine for QEMU/Docker testing
- posted {PATCH RFC 00/10} docker on non-x86 hosts Message-Id:
<20180718100505.7546-1-alex.bennee(a)linaro.org>
QEMU CI Loop ([VIRT-187])
- investigating porting existing RISU tests via qa-reports
- add additional test patterns :todo
[VIRT-187] https://projects.linaro.org/browse/VIRT-187
KVM CI Loop ([VIRT-2])
- need to sync-up on the current state of this work :todo
- started looking at Xiang's latest auto setup scripts
[VIRT-2] https://projects.linaro.org/browse/VIRT-2
[our wiki] https://wiki.linaro.org/Core/Virtualization
MTTCG tests ([VIRT-52])
- need to dust these off and get up-streamed if I'm going to add new
tests :todo
[VIRT-52] https://projects.linaro.org/browse/VIRT-52
Other Tasks
===========
- Submitted "My Other Machine is Virtual" abstract for YVR18
- Create an Instrumentation EPIC :todo
[arm64 story a bit more desktopy]
https://github.com/stsquad/gentoo/tree/arm-keywords-so-far
[Kata Containers] https://katacontainers.io/
[CrosVM] https://chromium.googlesource.com/chromiumos/platform/crosvm/
Completed Reviews [2/2]
=======================
{RFC PATCH 00/16} KVM: arm64: Initial support for SVE guests
Message-Id: <1529593060-542-1-git-send-email-Dave.Martin(a)arm.com>
- CLOSING NOTE [2018-07-26 Thu 11:18]
Did about 2/3rds of series, drew did the top few - re-spin on it's
way.
{PATCH v4 00/19} reverse debugging
Message-Id: <20180528071332.9424.27343.stgit@pasha-VirtualBox>
- CLOSING NOTE [2018-07-26 Thu 15:06]
v5 posted
Absences
========
- YVR18 Connect (17th-21st September 2018)
- KVM Forum 2018 (24th-26th October 2018)
Current Review Queue
====================
* {PATCH v5 00/24} Fixing record/replay and adding reverse debugging
Message-Id: <20180725121311.12867.21729.stgit@pasha-VirtualBox>
* {PATCH 0/5} tests/vm: Improvements when KVM is not available
Message-Id: <20180717024827.27897-1-f4bug(a)amsat.org>
* {RFC PATCH 00/12} tests/tcg: Add TriCore tests
Message-Id: <20180501142222.19154-1-kbastian(a)mail.uni-paderborn.de>
* {PATCH v4 00/14} fp-test + hardfloat
Message-Id: <1528768140-17894-1-git-send-email-cota(a)braap.org>
* {Qemu-devel} {RFC PATCH v2 0/7} QEMU binary instrumentation prototype
Message-Id: <152819515565.30857.16834004920507717324.stgit@pasha-ThinkPad-T60>
* {Qemu-devel} {RFC v2 0/2} Add BPF suuport to Qemu
Message-Id: <20180625110706.23332-1-sameeh(a)daynix.com>
--
Alex Bennée
Progress:
* VIRT-65 [QEMU upstream maintainership]
+ investigated required work for implementing HCR_EL2.TGE (the "trap
general exceptions" bit); identified what we've already implemented,
wrote patches for the other parts, and sent them out for review
+ sent patch to fix GICv3 emulation bug where we checked the wrong
HCR_EL2 bit when deciding whether to route IRQs to EL2
+ usual release-cycle related work
* VIRT-164 [improve Cortex-M emulation]
+ sent patch to fix a bug where we could escalate to the wrong HardFault
when AIRCR.BFHFNMINS is set
+ fixed bug where we had miswired the IoTKit timer1 IRQ line
+ fixed bug preventing VM state save/load for the NVIC with Security
extensions enabled
+ fixed "use of uninitialized memory" bug in the TZ-MPC model
+ had another look at the requirements for v8M stack-limit checking
+ implemented missing support for MPS2 FPGAIO up/down counter registers
+ started on a model of the CMSDK "dual-timer" module (as part of
looking at what remaining devices in the MPS2 are easy/worth
modelling so we can close out VIRT-182)
thanks
-- PMM
Following on from last weeks discussion here is an alternative abstract
which instead of looking to the future with where QEMU can go would
concentrate on what you can do with QEMU now. What do you think?
_____________________________
MY OTHER MACHINE IS VIRTUAL
Alex Bennée
_____________________________
YVR18
When working with new architectures there is often a scramble for
getting access to hardware. However hardware comes with it's own
problems - especially when it's new. It's hard to upgrade, hard to poke
around inside and hard to experiment with.
This is an area where QEMU can help. Thanks to it cross-architecture
emulation and ability to run full-system emulation it provides a
platform for experimentation without the potential consequences of
turning your new board into a inanimate brick.
This talk will start with an overview of QEMU and how various
configurations can be setup. We'll then examine various features
available that allow us to examine the run time behaviour of code inside
QEMU as well as discuss some of its limitations. Finally we'll look at
some experiments that would be hard to do with real hardware and what
they can tell us about the code we are running.
--
Alex Bennée
[Upstream]
Spent several days working with Alex and his docker testing bits.
Reproduced the reported ppc32 test failure. Wrote a patch to
implement the swapcontext syscall, which has now been merged.
Round 3 review of nanoMIPS submission.
Fixed a tricky issue wrt call-clobbered vector registers.
[VIRT-198 # QEMU: SVE Emulation Support ]
Some back and forth with Nils Meyer wrt SVE vs Grid.
TODO: Let the SVE vector length be selectable from the command-line.
r~
=== Work done during this 4.5day week ===
* TCWG-1062 (MCF branch prediction overload due to too many
consecutive branches):
+ rework reproduction steps around an existing script that does all
the steps of downloading and installing the benchmark and run it under
perf
+ gather what was observed that triggered the ticket I'm working on
-> narrowed down to 2/3 functions to be on the lookout
+ benchmark GCC and LLVM and compare the profile for these functions
-> bingo, I can see a branch issue
+ try to get assembly files to add nop and test performance again
-> code in assembly file is different from output of perf report,
need to rerun benchmark again to make sure I didn't fail there (sigh)
* TCWG-1379 / GCC PR85434 / CVE-2018-12886: upstream review
+ reply to upstream review comments
+ start to test tightening predicate for new instruction pattern
-> weird build error when trying to bootstrap unrelated to my
changes (missing header issues in stage 1 libgcc build)
* TCWG-1337 / LLVM PR34170:
+ respond to upstream review comments
* Continue work on TCWG-1428 (Support arithmetic on FileCheck regex variable):
+ hammer out syntax based on upstream feedback about what would be
desirable as FileCheck expressions
* Misc:
+ Linaro LLVM buildbot babysitting
+ Arm internal presentation
* Half a day off on Friday
=== Plan for week 30 ===
* TCWG-1428 (Support arithmetic on FileCheck regex variable): address comments
+ rework patch once syntax is agreed
* TCWG-1062 (MCF branch prediction overload due to too many
consecutive branches):
+ find out why assembly file from -save-temps is different from perf
report output
+ check performance when adding padding
+ start to investigate a solution
Progress:
* VIRT-65 [QEMU upstream maintainership]
+ code review
- another pass of the GICv2 virt support
- IMX6UL SoC support
- more patches for v6M support in core and NVIC
- PMU emulation improvements
+ rolled another 3.0 release candidate
* VIRT-164 [improve Cortex-M emulation]
+ implemented and sent a patchset for doing tailchaining of pending
exceptions during exception return
thanks
-- PMM
SVE Support ([VIRT-198])
========================
- converted [post on SVE development] to jekyl blog format
- a little fighting with the tooling but [draft on staging]
- trying to get compilers set-up to debug failing Grid Test_simd
testcase
- now have full 1yr armclang license for me and rth
- Test_simd passes with fresh build and current master
- not sure old binary fails - but Nils happy with current state
- fixed vector multiply bug on aarch64 backend
- posted {PATCH} tcg/aarch64: limit mul_vec size Message-Id:
<20180719154248.29669-1-alex.bennee(a)linaro.org>
- drafting [talk for HPC workshop on 26th]
- currently 11 minutes talking, need to expand
[VIRT-198] https://projects.linaro.org/browse/VIRT-198
[post on SVE development]
https://docs.google.com/document/d/15v1asqk-6de2RtA7ZWdIQ29PkY92gl3nlwG7_Se…
[draft on staging]
https://staging.linaro.org/blog/sve-in-qemu-linux-user/
[talk for HPC workshop on 26th]
https://docs.google.com/presentation/d/1Jz9ePpJ_YGd3vPXMj090VwRwPfBSYWHlSiz…
Write and submit Connect abstract
- "How-to use QEMU to test my software on no-silicon hardware"? :todo
- amalgamate HPC talk and blog post
SVE Reviews
- finish reviewing {RFC PATCH 00/16} KVM: arm64: Initial support for
SVE guests Message-Id:
<1529593060-542-1-git-send-email-Dave.Martin(a)arm.com> :todo
- stalled this week due to other activities
QEMU ARMv8.3 Support ([VIRT-241])
=================================
- had a [quick run at VHE] which crystallised some of the issues with
register aliasing
- obviously need to sit and think about a design for this
[VIRT-241] https://projects.linaro.org/browse/VIRT-241
[ARMv8.1 Mandatory Features]
https://projects.linaro.org/browse/TCWG-1434
[ARMv8.1 optional features] https://projects.linaro.org/browse/TCWG-1435
[quick run at VHE] https://github.com/stsquad/qemu/tree/add-vhe-rfc
Upstream Work ([VIRT-109])
==========================
- posted {PATCH v3 for 3.0 00/18} docker fixes (and one tcg test
tweak) Message-Id: <20180717195553.9111-1-alex.bennee(a)linaro.org>
[VIRT-109] https://projects.linaro.org/browse/VIRT-109
[v2 of docker fixes]
https://github.com/stsquad/qemu/tree/testing/docker-fixes-for-3.0-v2
[debootstrap master]
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=903657
Testing and CI
==============
- started looking at converting the CI RISU jobs to submit via
qa-reports
- got a Packet.net machine for QEMU/Docker testing
- posted {PATCH RFC 00/10} docker on non-x86 hosts Message-Id:
<20180718100505.7546-1-alex.bennee(a)linaro.org>
QEMU CI Loop ([VIRT-187])
- investigating porting existing RISU tests via qa-reports
- add additional test patterns :todo
[VIRT-187] https://projects.linaro.org/browse/VIRT-187
KVM CI Loop ([VIRT-2])
- need to sync-up on the current state of this work :todo
- started looking at Xiang's latest auto setup scripts
[VIRT-2] https://projects.linaro.org/browse/VIRT-2
[our wiki] https://wiki.linaro.org/Core/Virtualization
MTTCG tests ([VIRT-52])
- need to dust these off and get up-streamed if I'm going to add new
tests :todo
[VIRT-52] https://projects.linaro.org/browse/VIRT-52
Other Tasks
===========
- Create an Instrumentation EPIC :todo
[arm64 story a bit more desktopy]
https://github.com/stsquad/gentoo/tree/arm-keywords-so-far
[Kata Containers] https://katacontainers.io/
[CrosVM] https://chromium.googlesource.com/chromiumos/platform/crosvm/
Completed Reviews [6/6]
=======================
{PATCH v2 00/13} iommu: support txattrs, support TCG execution, implement TZ MPC
Message-Id: <20180604152941.20374-10-peter.maydell(a)linaro.org>
- CLOSING NOTE [2018-06-14 Thu 19:27]
Looks good.
{PATCH 0/8} Docker improvements
Message-Id: <20180628164643.9668-1-f4bug(a)amsat.org>
- CLOSING NOTE [2018-06-29 Fri 21:38]
Grabbed some patches, commented on others
{Qemu-arm} {PATCH v6 00/35} target/arm SVE patches
Message-Id: <20180627043328.11531-1-richard.henderson(a)linaro.org>
- CLOSING NOTE [2018-06-29 Fri 21:39]
Looks good
{Qemu-devel} {PATCH v5 00/35} target/arm SVE patches
Message-Id: <20180621015359.12018-1-richard.henderson(a)linaro.org>
- CLOSING NOTE [2018-06-29 Fri 21:39]
Looking good, stopped to move to v6
{PATCH 0/4} KVM: arm64: FPSIMD/SVE fixes for 4.17
Message-Id: <1528976039-25826-1-git-send-email-Dave.Martin(a)arm.com>
- CLOSING NOTE [2018-06-29 Fri 21:40]
Seems sane to me.
{Qemu-arm} {PATCH v3-a 00/27} target/arm: Scalable Vector Extension
Message-Id: <20180516223007.10256-1-richard.henderson(a)linaro.org>
- CLOSING NOTE [2018-07-13 Fri 20:02]
Already merged
Absences
========
- Friday 20th July
- YVR18 Connect (17th-21st September 2018)
- KVM Forum 2018 (24th-26th October 2018)
Current Review Queue
====================
* {RFC PATCH 00/16} KVM: arm64: Initial support for SVE guests
Message-Id: <1529593060-542-1-git-send-email-Dave.Martin(a)arm.com>
* {PATCH 0/5} tests/vm: Improvements when KVM is not available
Message-Id: <20180717024827.27897-1-f4bug(a)amsat.org>
* {PATCH v4 00/19} reverse debugging
Message-Id: <20180528071332.9424.27343.stgit@pasha-VirtualBox>
* {RFC PATCH 00/12} tests/tcg: Add TriCore tests
Message-Id: <20180501142222.19154-1-kbastian(a)mail.uni-paderborn.de>
* {PATCH v4 00/14} fp-test + hardfloat
Message-Id: <1528768140-17894-1-git-send-email-cota(a)braap.org>
* {Qemu-devel} {RFC PATCH v2 0/7} QEMU binary instrumentation prototype
Message-Id: <152819515565.30857.16834004920507717324.stgit@pasha-ThinkPad-T60>
--
Alex Bennée
[TCWG-1424] Using profile feedback to investigate code size
- Have most of the information I need to draw some conclusions. Should
have the remaining runs I need over the weekend.
- Next step is to analyse the data a bit more formally and write up.
- Discuss next steps. It may be worth polishing up the pass and
posting upstream as an RFC.
- Would like to wrap the investigation up by the end of July
On holiday on Friday 20th July and Monday 23rd July, back in the
office on Tuesday 24th.
[Upstream]
Fixed an arm32 host linux-user bug affecting shmat.
Added a ppc guest linux-user missing syscall, swapcontext.
Patch review for hardfreeze.
[VIRT-198 # QEMU: SVE Emulation Support ]
Fixed a LD1W (scalar plus vector) typo.
De-macro-ising sve_helper.c to aid debugging.
r~
SVE Support ([VIRT-198])
========================
- wrote up abstract for HPC workshop on 26th July
- started on presentation for workshop
- convert [post on SVE development] to jekly blog format and re-check
steps :todo
- trying to get compilers set-up to debug failing Grid Test_simd
testcase
- now have full 1yr armclang license for me and rth
[VIRT-198] https://projects.linaro.org/browse/VIRT-198
[post on SVE development]
https://docs.google.com/document/d/15v1asqk-6de2RtA7ZWdIQ29PkY92gl3nlwG7_Se…
SVE Reviews
- finish reviewing {RFC PATCH 00/16} KVM: arm64: Initial support for
SVE guests Message-Id:
<1529593060-542-1-git-send-email-Dave.Martin(a)arm.com> :todo
- stalled this week due to other activities
Upstream Work ([VIRT-109])
==========================
- posted {PATCH for 3.0 00/10} various docker fixes Message-Id:
<20180709152117.21585-1-alex.bennee(a)linaro.org>
- worked on [v2 of docker fixes]
- fixed recent regression in [debootstrap master] which we use
- and then fixed our scripts so we don't *always* use master
- posted {PATCH v2 for 3.0 00/16} various docker fixes Message-Id:
<20180713121741.19262-1-alex.bennee(a)linaro.org>
[VIRT-109] https://projects.linaro.org/browse/VIRT-109
[v2 of docker fixes]
https://github.com/stsquad/qemu/tree/testing/docker-fixes-for-3.0-v2
[debootstrap master]
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=903657
Testing and CI
==============
- started looking at converting the CI RISU jobs to submit via
qa-reports
- applied for packet.net bare metal machine for docker/kvm testing
QEMU CI Loop ([VIRT-187])
- investigating porting existing RISU tests via qa-reports
- add additional test patterns :todo
[VIRT-187] https://projects.linaro.org/browse/VIRT-187
KVM CI Loop ([VIRT-2])
- need to sync-up on the current state of this work :todo
- started looking at Xiang's latest auto setup scripts
[VIRT-2] https://projects.linaro.org/browse/VIRT-2
[our wiki] https://wiki.linaro.org/Core/Virtualization
MTTCG tests ([VIRT-52])
- need to dust these off and get up-streamed if I'm going to add new
tests :todo
[VIRT-52] https://projects.linaro.org/browse/VIRT-52
Other Tasks
===========
- Create an Instrumentation EPIC :todo
[arm64 story a bit more desktopy]
https://github.com/stsquad/gentoo/tree/arm-keywords-so-far
[Kata Containers] https://katacontainers.io/
[CrosVM] https://chromium.googlesource.com/chromiumos/platform/crosvm/
Completed Reviews [6/6]
=======================
{PATCH v2 00/13} iommu: support txattrs, support TCG execution, implement TZ MPC
Message-Id: <20180604152941.20374-10-peter.maydell(a)linaro.org>
- CLOSING NOTE [2018-06-14 Thu 19:27]
Looks good.
{PATCH 0/8} Docker improvements
Message-Id: <20180628164643.9668-1-f4bug(a)amsat.org>
- CLOSING NOTE [2018-06-29 Fri 21:38]
Grabbed some patches, commented on others
{Qemu-arm} {PATCH v6 00/35} target/arm SVE patches
Message-Id: <20180627043328.11531-1-richard.henderson(a)linaro.org>
- CLOSING NOTE [2018-06-29 Fri 21:39]
Looks good
{Qemu-devel} {PATCH v5 00/35} target/arm SVE patches
Message-Id: <20180621015359.12018-1-richard.henderson(a)linaro.org>
- CLOSING NOTE [2018-06-29 Fri 21:39]
Looking good, stopped to move to v6
{PATCH 0/4} KVM: arm64: FPSIMD/SVE fixes for 4.17
Message-Id: <1528976039-25826-1-git-send-email-Dave.Martin(a)arm.com>
- CLOSING NOTE [2018-06-29 Fri 21:40]
Seems sane to me.
{Qemu-arm} {PATCH v3-a 00/27} target/arm: Scalable Vector Extension
Message-Id: <20180516223007.10256-1-richard.henderson(a)linaro.org>
- CLOSING NOTE [2018-07-13 Fri 20:02]
Already merged
Absences
========
- Two days out due to illness
- YVR18 Connect (17th-21st September 2018)
- KVM Forum 2018 (24th-26th October 2018)
Current Review Queue
====================
* {RFC PATCH 00/16} KVM: arm64: Initial support for SVE guests
Message-Id: <1529593060-542-1-git-send-email-Dave.Martin(a)arm.com>
* {PATCH v4 00/19} reverse debugging
Message-Id: <20180528071332.9424.27343.stgit@pasha-VirtualBox>
* {RFC PATCH 00/12} tests/tcg: Add TriCore tests
Message-Id: <20180501142222.19154-1-kbastian(a)mail.uni-paderborn.de>
* {PATCH v4 00/14} fp-test + hardfloat
Message-Id: <1528768140-17894-1-git-send-email-cota(a)braap.org>
* {Qemu-devel} {RFC PATCH v2 0/7} QEMU binary instrumentation prototype
Message-Id: <152819515565.30857.16834004920507717324.stgit@pasha-ThinkPad-T60>
* {Qemu-devel} {RFC v2 0/2} Add BPF suuport to Qemu
Message-Id: <20180625110706.23332-1-sameeh(a)daynix.com>
--
Alex Bennée
4 day week, on holiday monday
Submitted a Linaro Connect presentation.
[TCWG-1424] Investigate profile feedback for code-size
Frustrating week trying to plug profile feedback into builds and
benchmarks and get sensible results
- First attempt was to use clang 2 stage pgo build
-- New pass manager has a bug that prevents clang from linking when I
enable clang instrumented profiling (local ref into discarded comdat
group containing counters)
-- Sample based profiling requires building create_llvm_prof from
Google's autofdo repository. Does not build out of the box after it
switched to using git submodules for its dependencies, managed to fix
up makefile to get it built.
-- Tried a sample profiling run but with perf's sampling rate and
clang's running time mean that the number of samples is too small to
give meaningful results.
-- The version of perf on my machine doesn't support incremental
profiling so I can't accumulate data from multiple runs.
-- Inlining before my pass to mark functions for size optimisation
accounts for majority of code size increase.
- Second attempt was integrating clang/llvm profiling into spec
-- Spent way longer than I'd expected working out how to write a
config file that handles sample and instrumentation based profile
runs. Both forms require the profile generated from perf or an
instrumented build to be post-processed before being used as an input
for the next stage. The sample profiling also needs the path to the
training executable which isn't obvious how to do.
-- Got SpecInt running with all the various combinations that I want
to run, haven't had time to do full runs to get results yet
== Progress ==
* FDPIC
- GCC: posted patch series v2.
* GCC upstream validation:
- looking at some random noise in testing
- reported a couple of regressions
* Infrastructure:
- prototyped native toolchain build job
- misc cleanups
* misc (conf-calls, meetings, emails, ....)
== Next ==
Holidays for 2 weeks, back on July 30th
Progress:
* VIRT-65 [QEMU upstream maintainership]
+ tracked down and sent fix for bug in MPU handling of exception
frame unstacking that broke a Zephyr test case
+ sent some patches for minor GICv2 bugs
+ code review:
- large series adding virtualization support to GICv2
* VIRT-164 [improve Cortex-M emulation]
+ completed patchset that implements execution from small MPU regions
and MMIO regions, and sent it out for review
+ found and fixed a few bugs in the code I was modifying in the process
thanks
-- PMM
=== Work done during this week ===
* Continue work on TCWG-1428 (Support arithmetic on FileCheck regex
variable): external review
+ finish adding comments
+ add documentation and testcase
+ respond to feedback and send email to llvm-dev to discuss best
syntax for new feature
* Started looking into TCWG-1062 (MCF branch prediction overload due
to too many consecutive branches):
+ figure out what machines to run spec on, where to find spec and
how to use Linaro scripts to install/configure and run it (thanks to
Christophe Lyon)
+ try to build a native clang toolchain but throw it away since
clang does not link (perhaps due to lack of memory (4G machine))
+ learn how to build a cross LLVM toolchain (thanks to Peter Smith)
+ figure out how to get the right privilege to run perf (thanks to
Christophe Lyon)
* Misc:
+ LLVM buildbot babysitting with Peter Smith
+ attend presentation about Windows on Arm
+ start a full reorganization of my workflow
+ finish handover of my Arm tickets
=== Plan for week 28 ===
* DSGHACK-25 (Support arithmetic on FileCheck regex variable): address comments
+ rework patch once syntax is agreed
* Continue looking into MCF branch prediction overload due to too many
consecutive branches:
+ reproduce/confirm issue
+ start to investigate a solution
[VIRT-198 # QEMU: SVE Emulation Support ]
Fixed a couple of bugs uncovered by Alex's VQ16 traces.
[VIRT-249 # SVE System Mode ]
Tracked a phantom kernel crash for a while before it
magically went away with a qemu from-scratch rebuild.
(Plus other stuff, maybe? I tried a lot of things.)
Wrote a version of helper_sve_ldff1_bb_r that works
on pages, and works with softmmu.
time ./bld/tests/test-strlen
softmmu: 0m5.467s
linux-user (old): 0m2.016s
linux-user (new): 0m1.853s
Still need to generalize this to the other first-fault/
no-fault helpers. And possibly write some synthetic test
cases for them. Certainly they've not been tested so
far by anything.
[QEMU Upstream]
* tcg-next pull request.
* Review of some ppc fpu patches went too many rounds
before I broke down and wrote some patches myself.
* More nanomips review.
[GCC Upstream]
Fixed some problems with, and committed, the movprfx patches.
r~
[TCWG-1368] Tracked down libfuzzer buildbot failures on aarch64 and raised PR
[TCWG-1424] Use profile information for size optimisation
- Decided to use clang's 2-stage PGO build as next experiment with
compile times on the full test suite as the performance benchmarks
- Spent rather too much time trying to inject an extra c-flag into the
right stage of the bootstrap builds. As a consolation I know a little
bit more about the bootstrap builds.
- Just measuring code size the profile guided feedback builds of clang
are roughly 33% larger than standard clang, with cold functions
optimised for size this drops to 25% larger. Still waiting for
performance figures for all runs. It is looking like in its current
formulation the size optimisation might offer most of the benefits of
PGO but with a lower code size impact. It misses the original goal of
keeping the performance of non-PGO optimisation but lower overall
size.
[Misc] Tracked down a LLD static build failure with a recent glibc.
Looks like it won't affect Arm and AArch64 as it is related to X86
relaxed got relocations to ifunc resolvers.
Planned absences
- Holiday Monday 9th July
Progress:
* VIRT-65 [QEMU upstream maintainership]
+ softfreeze-related maintenance work
+ investigating reported bug with CMSDK timer device model:
couldn't reproduce hangs, but sent patches which fix
various issues
+ code review:
- various patches by the Outreachy/GSoC interns for
the v6M/microbit work
- a few OSX UI bugfix patches
+ scrub through some recently filed bugs to see what might be
worth investigating before the release
+ first pass through KVM Forum talk submissions
thanks
-- PMM
=== Work done during this week ===
* PR85434 / CVE-2018-12886 / TCWG-1379 (stack-protector failure on GCC
ARM): external review
+ finish testing and patch clean up (comments + changelog) and
submit for external review
* Continue work on TCWG-1428 (Support arithmetic on FileCheck regex variable):
+ finish implementation, fix compile issues and debug errors found
on simple testcase
+ run regression testsuite and fix another issue
+ start cleaning up patch
* Misc improvement to jenkins infrastructure
* Misc:
+ gave presentation on stack protector bug
https://docs.google.com/presentation/d/1ksqK-eTYjYhFXlTyVaPA2VIvCTsxwO5Xw-G…
+ Future of microprocessors presentation by Sophie Wilson
=== Plan for week 28 ===
* TCWG-1428 (Support arithmetic on FileCheck regex variable): submit
for external review
+ finish adding comments
+ add documentation and testcase
* Start looking into MCF branch prediction overload due to too many
consecutive branches
SVE Support ([VIRT-198])
========================
- wrote up [post on SVE development] with QEMU for for Linaro Blog
- originally planned to publish on QEMU 3.0 release
- HPC team would like it published before their workshop on 26th
July
- write up a abstract for HPC workshop and plan remote time :todo
[VIRT-198] https://projects.linaro.org/browse/VIRT-198
[post on SVE development]
https://docs.google.com/document/d/15v1asqk-6de2RtA7ZWdIQ29PkY92gl3nlwG7_Se…
RISU Support for SVE ([VIRT-199])
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- CLOSING NOTE [2018-07-06 Fri 12:37]
Changes merged upstream. Ticket closed.
- generated more traces at different VQ's
- VQ3 (found one error, actually x86 SIGFPE issue)
- VQ16 (found 2 errors in ptrue)
- initial run included errors in whilelo, whilels, wrffr, zip[12]
which went away
- I've parked the tests from ASL work pending legal feedback
[VIRT-199] https://projects.linaro.org/browse/VIRT-199
SVE Reviews
~~~~~~~~~~~
- started reviewing {RFC PATCH 00/16} KVM: arm64: Initial support for
SVE guests Message-Id:
<1529593060-542-1-git-send-email-Dave.Martin(a)arm.com>
QEMU ARMv8.3 Support ([VIRT-241])
=================================
- added remaining v8.1 stories to JIRA and re-organised under
- [ARMv8.1 Mandatory Features] and [ARMv8.1 optional features]
- pondering how much effort to do VHE
- it's mostly conditional re-direction of EL1/EL2 registers so
host kernel can pretend it's in EL1 when really in EL2
- some EL2 registers present slightly different formats when VHE
bit is set
[VIRT-241] https://projects.linaro.org/browse/VIRT-241
[ARMv8.1 Mandatory Features]
https://projects.linaro.org/browse/TCWG-1434
[ARMv8.1 optional features] https://projects.linaro.org/browse/TCWG-1435
Upstream Work ([VIRT-109])
==========================
- posted {PATCH v3 00/20} Travis, Code Coverage and Cross Build
updates Message-Id: <20180702143021.18864-1-alex.bennee(a)linaro.org>
- posted {PULL 00/20} Travis, Code Coverage and Cross Build updates
Message-Id: <20180703101444.23778-12-alex.bennee(a)linaro.org>
- with a follow-up of {PULL v2 00/20} Travis, Code Coverage and
Cross Build updates Message-Id:
<20180704090642.3469-1-alex.bennee(a)linaro.org>
- and {PULL v3 00/20} Travis, Code Coverage and Cross Build updates
Message-Id: <20180705160329.30386-1-alex.bennee(a)linaro.org>
- now merged \o/
[VIRT-109] https://projects.linaro.org/browse/VIRT-109
Testing and CI
==============
- spoke with LAVA team about build status and build button
- now have a qa-reports account to submit LAVA jobs via
QEMU CI Loop ([VIRT-187])
~~~~~~~~~~~~~~~~~~~~~~~~~
- investigating porting existing RISU tests via qa-reports
- add additional test patterns :todo
[VIRT-187] https://projects.linaro.org/browse/VIRT-187
KVM CI Loop ([VIRT-2])
~~~~~~~~~~~~~~~~~~~~~~
- need to sync-up on the current state of this work :todo
- started looking at Xiang's latest auto setup scripts
[VIRT-2] https://projects.linaro.org/browse/VIRT-2
[our wiki] https://wiki.linaro.org/Core/Virtualization
MTTCG tests ([VIRT-52])
~~~~~~~~~~~~~~~~~~~~~~~
- need to dust these off and get up-streamed if I'm going to add new
tests :todo
[VIRT-52] https://projects.linaro.org/browse/VIRT-52
Other Tasks
===========
- Spoke to Ilias Apalodimas (LEDGE SIG) about VM networking
- options for zero copy guest to guest networking
- experiments with userspace networking stacks
- lightweight VM+containers
- [Kata Containers] - follow on from Clear Containers work
- Crostini/[CrosVM] work, ChromeOS VM+Docker approach
- Create an Instrumentation EPIC :todo
[Kata Containers] https://katacontainers.io/
[CrosVM] https://chromium.googlesource.com/chromiumos/platform/crosvm/
Completed Reviews [5/5]
=======================
{PATCH v2 00/13} iommu: support txattrs, support TCG execution, implement TZ MPC
Message-Id: <20180604152941.20374-10-peter.maydell(a)linaro.org>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- CLOSING NOTE [2018-06-14 Thu 19:27]
Looks good.
{PATCH 0/8} Docker improvements
Message-Id: <20180628164643.9668-1-f4bug(a)amsat.org>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- CLOSING NOTE [2018-06-29 Fri 21:38]
Grabbed some patches, commented on others
{Qemu-arm} {PATCH v6 00/35} target/arm SVE patches
Message-Id: <20180627043328.11531-1-richard.henderson(a)linaro.org>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- CLOSING NOTE [2018-06-29 Fri 21:39]
Looks good
{Qemu-devel} {PATCH v5 00/35} target/arm SVE patches
Message-Id: <20180621015359.12018-1-richard.henderson(a)linaro.org>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- CLOSING NOTE [2018-06-29 Fri 21:39]
Looking good, stopped to move to v6
{PATCH 0/4} KVM: arm64: FPSIMD/SVE fixes for 4.17
Message-Id: <1528976039-25826-1-git-send-email-Dave.Martin(a)arm.com>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- CLOSING NOTE [2018-06-29 Fri 21:40]
Seems sane to me.
Absences
========
- YVR18 Connect (17th-21st September 2018)
- KVM Forum 2018 (24th-26th October 2018)
Current Review Queue
====================
* {RFC PATCH 00/16} KVM: arm64: Initial support for SVE guests
Message-Id: <1529593060-542-1-git-send-email-Dave.Martin(a)arm.com>
* {Qemu-devel} {RFC v2 0/2} Add BPF suuport to Qemu
Message-Id: <20180625110706.23332-1-sameeh(a)daynix.com>
* {PATCH v4 00/19} reverse debugging
Message-Id: <20180528071332.9424.27343.stgit@pasha-VirtualBox>
* {RFC PATCH 00/12} tests/tcg: Add TriCore tests
Message-Id: <20180501142222.19154-1-kbastian(a)mail.uni-paderborn.de>
* {PATCH 0/4} tests/vm: various trivial fixes
Message-Id: <20180628153535.1411-1-f4bug(a)amsat.org>
* {PATCH 0/6} docker: Port to Python 3
Message-Id: <20180627021423.18404-1-ehabkost(a)redhat.com>
--
Alex Bennée
== Progress ==
* FDPIC
- GCC patch series: updating patches.
- uclibc-ng: discussing problem with lib symbols not being weak.
It's not a blocker for FDPIC anyway. Continued to update/clean the
patch series before submission.
* GCC upstream validation:
- looking at some random noise in testing
- reported a couple of regressions
* Infrastructure:
- patch reviews
- cleanup/improvements
* misc (conf-calls, meetings, emails, ....)
== Next ==
* FDPIC: uclibc-ng, GCC
* GCC upstream validation
o One day off
o LLVM bots
* Troubleshot sanitizers regressions on ARM
o LLVM Machine Outliner on ARM
* Rebased prototype on upstream developments
* Reviewing upstream patch on intra-procedure-call
scratch register handling.
* Investigating potential issues w/r to pass ordering
o Misc
* Various meetings and discussions.
[VIRT-198 # QEMU: SVE Emulation Support ]
Full aarch64-linux-user patch set merged.
[VIRT-214 # SVE System Registers ]
Implemented ID_AA64PFR0_EL1, ID_AA64ZFR0_EL1.
[VIRT-249 # SVE System Mode ]
Fixed sve disabled exception routing.
A booted kernel recognizes sve is present, according to /proc/cpuinfo.
However, the kernel crashes as soon as the first sve insn is executed.
Task for next week is to find out why.
r~
SVE Support ([VIRT-198])
========================
- posted {PATCH v3 0/5} support reading some CPUID/CNT registers from
user-space Message-Id:
<20180625160009.17437-1-alex.bennee(a)linaro.org>
- needed for the HPC guys in their test setups
- pm has grabbed the CNT patches, the rest need rework, not this
cycle
[VIRT-198] https://projects.linaro.org/browse/VIRT-198
RISU Support for SVE ([VIRT-199])
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- posted {RISU PATCH v4 00/22} ARM SVE support for RISU Message-Id:
<20180622141205.16306-1-alex.bennee(a)linaro.org>
- support load/store memory instructions from ASL :todo
- awaiting legal clearance from ARM to publish script
- generated more traces at different VQ's
- VQ3 (found one error, actually x86 SIGFPE issue)
- VQ16 (still generating :-/)
[VIRT-199] https://projects.linaro.org/browse/VIRT-199
[iteration of SVE series]
https://github.com/stsquad/risu/tree/add-sve-support-v3
SVE Reviews
~~~~~~~~~~~
- reviewed {Qemu-devel} {PATCH v5 00/35} target/arm SVE patches
Message-Id: <20180621015359.12018-1-richard.henderson(a)linaro.org>
Upstream Work ([VIRT-109])
==========================
- posted {PATCH v1 00/10} Travis updates and code coverage tweaks
Message-Id: <20180625111935.26108-1-alex.bennee(a)linaro.org>
- spent some time looking at getting xtensa system test stuff done
- posted {PATCH v2 00/21} Travis, Code Coverage and Cross Build
updates Message-Id: <20180629205232.27190-1-alex.bennee(a)linaro.org>
[VIRT-109] https://projects.linaro.org/browse/VIRT-109
[hacky fix]
https://github.com/stsquad/qemu/commit/a15577f8a6629f9924d2671a82f0b9801351…
KVM CI Loop ([VIRT-2])
======================
- need to sync-up on the current state of this work :todo
- spoke with LAVA team about build status and build button
- now have a qa-reports account to submit LAVA jobs via
[VIRT-2] https://projects.linaro.org/browse/VIRT-2
[our wiki] https://wiki.linaro.org/Core/Virtualization
Other Tasks
===========
[arm64 story a bit more desktopy]
https://github.com/stsquad/gentoo/tree/arm-keywords-so-far
Completed Reviews [1/1]
=======================
{PATCH v2 00/13} iommu: support txattrs, support TCG execution, implement TZ MPC
Message-Id: <20180604152941.20374-10-peter.maydell(a)linaro.org>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- CLOSING NOTE [2018-06-14 Thu 19:27]
Looks good.
{PATCH 0/8} Docker improvements
Message-Id: <20180628164643.9668-1-f4bug(a)amsat.org>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- CLOSING NOTE [2018-06-29 Fri 21:38]
Grabbed some patches, commented on others
{Qemu-arm} {PATCH v6 00/35} target/arm SVE patches
Message-Id: <20180627043328.11531-1-richard.henderson(a)linaro.org>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- CLOSING NOTE [2018-06-29 Fri 21:39]
Looks good
{Qemu-devel} {PATCH v5 00/35} target/arm SVE patches
Message-Id: <20180621015359.12018-1-richard.henderson(a)linaro.org>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- CLOSING NOTE [2018-06-29 Fri 21:39]
Looking good, stopped to move to v6
{PATCH 0/4} KVM: arm64: FPSIMD/SVE fixes for 4.17
Message-Id: <1528976039-25826-1-git-send-email-Dave.Martin(a)arm.com>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- CLOSING NOTE [2018-06-29 Fri 21:40]
Seems sane to me.
Absences
========
- YVR18 Connect (17th-21st September 2018)
- KVM Forum 2018 (24th-26th October 2018)
Current Review Queue
====================
* {PATCH v4 00/19} reverse debugging
Message-Id: <20180528071332.9424.27343.stgit@pasha-VirtualBox>
* {RFC PATCH 00/12} tests/tcg: Add TriCore tests
Message-Id: <20180501142222.19154-1-kbastian(a)mail.uni-paderborn.de>
* {PATCH 0/4} tests/vm: various trivial fixes
Message-Id: <20180628153535.1411-1-f4bug(a)amsat.org>
* {PATCH 0/6} docker: Port to Python 3
Message-Id: <20180627021423.18404-1-ehabkost(a)redhat.com>
* {PATCH v4 00/14} fp-test + hardfloat
Message-Id: <1528768140-17894-1-git-send-email-cota(a)braap.org>
* {RFC PATCH 00/16} KVM: arm64: Initial support for SVE guests
Message-Id: <1529593060-542-1-git-send-email-Dave.Martin(a)arm.com>
--
Alex Bennée
