Re: [Qemu-devel] [PATCH V8 4/4] tests: Add migration test for aarch64

[Andrew Jones]

On Sat, Sep 01, 2018 at 11:07:26AM +0100, Peter Maydell wrote:
> On 1 September 2018 at 06:11, Wei Huang <address@hidden> wrote:
> > This patch adds migration test support for aarch64. The test code, which
> > implements the same functionality as x86, is booted as a kernel in qemu.
> > Here are the design choices we make for aarch64:
> >
> >  * We choose this -kernel approach because aarch64 QEMU doesn't provide a
> >    built-in fw like x86 does. So instead of relying on a boot loader, we
> >    use -kernel approach for aarch64.
> >  * The serial output is sent to PL011 directly.
> >  * The physical memory base for mach-virt machine is 0x40000000. We change
> >    the start_address and end_address for aarch64.
> >
> > In addition to providing the binary, this patch also includes the source
> > code and the build script in tests/migration/aarch64. So users can change
> > the source and/or re-compile the binary as they wish.
> > +    } else if (strcmp(arch, "aarch64") == 0) {
> > +        struct utsname utsname;
> > +
> 
> The comment says:
> 
> > +        /* kvm and tcg need different cpu and gic-version configs */
> 
> ...but the code below it doesn't change the cpu or gic-version
> based on 'accel'.
> 
> > +        if (access("/dev/kvm", F_OK) == 0 && uname(&utsname) == 0 &&
> > +            strcmp(utsname.machine, "aarch64") == 0) {
> > +            accel = "kvm";
> > +        } else {
> > +            accel = "tcg";
> > +        }
> 
> Maybe we could just use -accel=kvm,tcg rather than guessing
> whether kvm is going to work ? If this is how the x86 code
> works then probably best to do the same as that, though.

Yeah, using '-accel=kvm:tcg' is what I suggested in the v7 review when
suggesting to switch to -cpu max and gic-version=max. That allows the
uname() use and the new utsname.h include to go away.

Thanks,
drew

> 
> > +
> > +        init_bootfile(bootpath, aarch64_kernel);
> > +        cmd_src = g_strdup_printf("-machine virt,accel=%s,gic-version=max "
> > +                                  "-name vmsource,debug-threads=on -cpu 
> > max "
> > +                                  "-m 150M -serial file:%s/src_serial "
> > +                                  "-kernel %s ",
> > +                                  accel, tmpfs, bootpath);
> > +        cmd_dst = g_strdup_printf("-machine virt,accel=%s,gic-version=max "
> > +                                  "-name vmdest,debug-threads=on -cpu max "
> > +                                  "-m 150M -serial file:%s/dest_serial "
> > +                                  "-kernel %s "
> > +                                  "-incoming %s ",
> > +                                  accel, tmpfs, bootpath, uri);
> > +
> > +        start_address = ARM_TEST_MEM_START;
> > +        end_address = ARM_TEST_MEM_END;
> > +
> > +        g_assert(sizeof(aarch64_kernel) <= ARM_TEST_MAX_KERNEL_SIZE);
> 
> thanks
> -- PMM
>