Re: [PATCH for-5.1 V3 0/7] mips: Add Loongson-3 machine support (with KVM)

[Huacai Chen]

Hi, Aleksandar,

On Tue, May 5, 2020 at 6:12 PM Aleksandar Markovic
<address@hidden> wrote:
>
>
>
> уторак, 05. мај 2020., chen huacai <address@hidden> је написао/ла:
>>
>> Hi, Aleksandar,
>>
>> On Sun, May 3, 2020 at 6:50 PM Aleksandar Markovic
>> <address@hidden> wrote:
>> >
>> > нед, 3. мај 2020. у 12:21 Huacai Chen <address@hidden> је написао/ла:
>> > >
>> > > Loongson-3 CPU family include Loongson-3A R1/R2/R3/R4 and Loongson-3B
>> > > R1/R2. Loongson-3A R1 is the oldest and its ISA is the smallest, while
>> > > Loongson-3A R4 is the newest and its ISA is almost the superset of all
>> > > others. To reduce complexity, in QEMU we just define two CPU types:
>> > >
>> > > 1, "Loongson-3A1000" CPU which is corresponding to Loongson-3A R1. It is
>> > >    suitable for TCG because Loongson-3A R1 has fewest ASE.
>> > > 2, "Loongson-3A4000" CPU which is corresponding to Loongson-3A R4. It is
>> > >    suitable for KVM because Loongson-3A R4 has the VZ ASE.
>> > >
>> >
>> > Huacai, thanks for putting together v3, which is a little better than v2, 
>> > and
>> > thanks for addressing my previous suggestions.
>> >
>> > Now, give us some time to digest new data on Loongson3.  We will
>> > respond, but it won't happen immediately, which is, you'd agree,
>> > reasonable. Just be patient.
>> >
>> > But again, in general, I salute your efforts very much!
>> >
>> > Yours, Aleksandar
>> I'm sorry for this late response because I have done many tests to
>> reproduce the problem reported at
>> https://patchew.org/QEMU/address@hidden/,
>> but I don't have such a failure...
>>
>> What I have done:
>> 1, "make check" on MIPS64 platform (distro is Fedora28 for Loongson);
>> 2, "make check" on X86_64 platform (distro is RHEL8);
>> 3, "make docker-test-quick@centos7 SHOW_ENV=1 NETWORK=1" on X86_64
>> platform (distro is RHEL8);
>> 4, "make docker-test-quick@centos7 SHOW_ENV=1 J=n NETWORK=1" on X86_64
>> platform (distro is RHEL8 and I've tried n=2,3,4....14);
>>
>> I always get the same result:
>> Not run: 259
>> Passed all 117 iotests
>>
>> And, it seems that my patchset doesn't touch anything about iotests,
>> so I don't know why the build test fails on iotests 192 (Maybe your
>> build test has the same problem without my patches).
>>
>
> From time to time, there is some instability in our automatic iotests. You 
> shouldn't bother too much about it, of course you retest in your 
> environments, that is good. But, in all likelyhood, your patchset doesn't 
> really have anything to do with the reported iotest failure.

Thank you for your help, and here is another question: Could
"target/mips: Support variable page size" series be merged now? This
Loongson-3 series depend on variable page size logically.

>
> Truly yours,
> Aleksandar
>
>
>>
>> P.S.: I have found a problem that my patchset has a build failure with
>> CONFIG_KVM=n, but this is another problem and I will send V4 to fix it
>> (after collecting all problems in V3).
>>
>>
>> >
>> > > Loongson-3 lacks English documents. I've tried to translated them with
>> > > translate.google.com, and the machine translated documents (together
>> > > with their original Chinese versions) are available here.
>> > >
>> > > Loongson-3A R1 (Loongson-3A1000)
>> > > User Manual Part 1:
>> > > http://ftp.godson.ac.cn/lemote/3A1000_p1.pdf
>> > > http://ftp.godson.ac.cn/lemote/Loongson3A1000_processor_user_manual_P1.pdf
>> > >  (Chinese Version)
>> > > User Manual Part 2:
>> > > http://ftp.godson.ac.cn/lemote/3A1000_p2.pdf
>> > > http://ftp.godson.ac.cn/lemote/Loongson3A1000_processor_user_manual_P2.pdf
>> > >  (Chinese Version)
>> > >
>> > > Loongson-3A R2 (Loongson-3A2000)
>> > > User Manual Part 1:
>> > > http://ftp.godson.ac.cn/lemote/3A2000_p1.pdf
>> > > http://ftp.godson.ac.cn/lemote/Loongson3A2000_user1.pdf (Chinese Version)
>> > > User Manual Part 2:
>> > > http://ftp.godson.ac.cn/lemote/3A2000_p2.pdf
>> > > http://ftp.godson.ac.cn/lemote/Loongson3A2000_user2.pdf (Chinese Version)
>> > >
>> > > Loongson-3A R3 (Loongson-3A3000)
>> > > User Manual Part 1:
>> > > http://ftp.godson.ac.cn/lemote/3A3000_p1.pdf
>> > > http://ftp.godson.ac.cn/lemote/Loongson3A3000_3B3000usermanual1.pdf 
>> > > (Chinese Version)
>> > > User Manual Part 2:
>> > > http://ftp.godson.ac.cn/lemote/3A3000_p2.pdf
>> > > http://ftp.godson.ac.cn/lemote/Loongson3A3000_3B3000usermanual2.pdf 
>> > > (Chinese Version)
>> > >
>> > > Loongson-3A R4 (Loongson-3A4000)
>> > > User Manual Part 1:
>> > > http://ftp.godson.ac.cn/lemote/3A4000_p1.pdf
>> > > http://ftp.godson.ac.cn/lemote/3A4000user.pdf (Chinese Version)
>> > > User Manual Part 2:
>> > > I'm sorry that it is unavailable now.
>> > >
>> > > We are preparing to add QEMU's Loongson-3 support. MIPS VZ extension is
>> > > fully supported in Loongson-3A R4+, so we at first add QEMU/KVM support
>> > > in this series. And the next series will add QEMU/TCG support (it will
>> > > emulate Loongson-3A R1).
>> > >
>> > > We already have a full functional Linux kernel (based on Linux-5.4.x LTS
>> > > but not upstream yet) here:
>> > >
>> > > https://github.com/chenhuacai/linux
>> > >
>> > > How to use QEMU/Loongson-3?
>> > > 1, Download kernel source from the above URL;
>> > > 2, Build a kernel with arch/mips/configs/loongson3_{def,hpc}config;
>> > > 3, Boot a Loongson-3A4000 host with this kernel;
>> > > 4, Build QEMU-5.0.0 with this patchset;
>> > > 5, modprobe kvm;
>> > > 6, Use QEMU with TCG (available in future):
>> > >        qemu-system-mips64el -M loongson3,accel=tcg -cpu Loongson-3A1000 
>> > > -kernel <path_to_kernel> -append ...
>> > >    Use QEMU with KVM (available at present):
>> > >        qemu-system-mips64el -M loongson3,accel=kvm -cpu Loongson-3A4000 
>> > > -kernel <path_to_kernel> -append ...
>> > >
>> > >    The "-cpu" parameter can be omitted here and QEMU will use the 
>> > > correct type for TCG/KVM automatically.
>> > >
>> > > V1 -> V2:
>> > > 1, Add a cover letter;
>> > > 2, Improve CPU definitions;
>> > > 3, Remove LS7A-related things (Use GPEX instead);
>> > > 4, Add a description of how to run QEMU/Loongson-3.
>> > >
>> > > V2 -> V3:
>> > > 1, Fix all possible checkpatch.pl errors and warnings.
>> > >
>> > > Huacai Chen(7):
>> > >  configure: Add KVM target support for MIPS64
>> > >  hw/mips: Implement the kvm_type() hook in MachineClass
>> > >  hw/mips: Add CPU IRQ3 delivery for KVM
>> > >  target/mips: Add Loongson-3 CPU definition
>> > >  target/mips: Add more CP0 register for save/restor
>> > >  hw/mips: Add Loongson-3 machine support (with KVM)
>> > >  MAINTAINERS: Add myself as Loongson-3 maintainer
>> > >
>> > > Signed-off-by: Huacai Chen <address@hidden>
>> > > ---
>> > >  MAINTAINERS                          |   5 +
>> > >  configure                            |   2 +-
>> > >  default-configs/mips64el-softmmu.mak |   1 +
>> > >  hw/core/Makefile.objs                |   2 +-
>> > >  hw/core/null-machine.c               |   4 +
>> > >  hw/mips/Kconfig                      |  10 +
>> > >  hw/mips/Makefile.objs                |   3 +-
>> > >  hw/mips/common.c                     |  31 ++
>> > >  hw/mips/mips_int.c                   |   4 +-
>> > >  hw/mips/mips_loongson3.c             | 901 
>> > > +++++++++++++++++++++++++++++++++++
>> > >  include/hw/mips/mips.h               |   3 +
>> > >  target/mips/cpu.h                    |  28 ++
>> > >  target/mips/internal.h               |   2 +
>> > >  target/mips/kvm.c                    | 212 +++++++++
>> > >  target/mips/machine.c                |   6 +-
>> > >  target/mips/mips-defs.h              |   7 +-
>> > >  target/mips/translate.c              |   2 +
>> > >  target/mips/translate_init.inc.c     |  86 ++++
>> > >  18 files changed, 1300 insertions(+), 9 deletions(-)
>> > >  create mode 100644 hw/mips/common.c
>> > >  create mode 100644 hw/mips/mips_loongson3.c
>> > > --
>> > > 2.7.0
>>
>>
>>
>> --
>> Huacai Chen
Best regards,
Huacai