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

[Huacai Chen]

Hi, Aleksandar,

On Thu, May 7, 2020 at 8:18 PM Aleksandar Markovic
<address@hidden> wrote:
>
> сре, 6. мај 2020. у 03:43 Huacai Chen <address@hidden> је написао/ла:
> >
> > 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.
> >
>
> Hi, Huacei.
>
> Please be patient. This is a significant series, and we don't do or
> have a "fast track" for series of such nature. It might or might not
> be that some of the patches will be accepted before the entire series,
> but certainly do not rush us. This is not the way to achieve your
> goal, let's put it that way. Focus on improving your series. Being
> careful with reviewing and upstreaming is actually in your interest.
Thank your very much. I know I should be patient, and I'm patient
actually. I mention "target/mips: Support variable page size" here
because I forget to add "for-5.1" in that series, I want to know
whether I should resend it.

>
> Yours,
> Aleksandar
>
> > >
> > > 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