Re: [PATCH v2 1/3] tests/migration-test: Stick with gicv3 in aarch64 test

[Thomas Huth]

On 19/02/2024 13.50, Peter Maydell wrote:
> On Mon, 19 Feb 2024 at 11:54, Thomas Huth <thuth@redhat.com> wrote:
> > On 07/02/2024 01.54, peterx@redhat.com wrote:
> > > From: Peter Xu <peterx@redhat.com>
> > >
> > > Recently we introduced cross-binary migration test.  It's always wanted
> > > that migration-test uses stable guest ABI for both QEMU binaries in this
> > > case, so that both QEMU binaries will be compatible on the migration
> > > stream with the cmdline specified.
> > >
> > > Switch to a static gic version "3" rather than using version "max", so that
> > > GIC should be stable now across any future QEMU binaries for migration-test.
> > >
> > > Here the version can actually be anything as long as the ABI is stable.  We
> > > choose "3" because it's the majority of what we already use in QEMU while
> > > still new enough: "git grep gic-version=3" shows 6 hit, while version 4 has
> > > no direct user yet besides "max".
> > >
> > > Note that even with this change, aarch64 won't be able to work yet with
> > > migration cross binary test, but then the only missing piece will be the
> > > stable CPU model.
> > >
> > > Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
> > > Signed-off-by: Peter Xu <peterx@redhat.com>
> > > ---
> > >    tests/qtest/migration-test.c | 2 +-
> > >    1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/tests/qtest/migration-test.c b/tests/qtest/migration-test.c
> > > index 7675519cfa..8a5bb1752e 100644
> > > --- a/tests/qtest/migration-test.c
> > > +++ b/tests/qtest/migration-test.c
> > > @@ -819,7 +819,7 @@ static int test_migrate_start(QTestState **from, QTestState 
> > > **to,
> > >        } else if (strcmp(arch, "aarch64") == 0) {
> > >            memory_size = "150M";
> > >            machine_alias = "virt";
> > > -        machine_opts = "gic-version=max";
> > > +        machine_opts = "gic-version=3";
> > >            arch_opts = g_strdup_printf("-cpu max -kernel %s", bootpath);
> > >            start_address = ARM_TEST_MEM_START;
> > >            end_address = ARM_TEST_MEM_END;
> >
> > Looks like the migration test now fails on aarch64 when "configure" has been
> > run with "--without-default-devices", since that disables the gicv3 in the
> > binary ... is there a way to check whether the gicv3 is available, and use
> > "=max" instead if it is not?
>
> A QEMU for AArch64 with no GICv3 is of very little practical use,
> so I'm not sure it makes sense to allow users to build one like that.

Ok, if it doesn't make too much sense to build without GICv3, maybe a patch 
like this could be the right solution:

diff --git a/hw/intc/Kconfig b/hw/intc/Kconfig
--- a/hw/intc/Kconfig
+++ b/hw/intc/Kconfig
@@ -12,10 +12,6 @@ config IOAPIC
     bool
     select I8259

-config ARM_GIC
-    bool
-    select MSI_NONBROKEN
-
 config OPENPIC
     bool
     select MSI_NONBROKEN
@@ -25,14 +21,18 @@ config APIC
     select MSI_NONBROKEN
     select I8259

+config ARM_GIC
+    bool
+    select ARM_GICV3_TCG if TCG
+    select ARM_GIC_KVM if KVM
+    select MSI_NONBROKEN
+
 config ARM_GICV3_TCG
     bool
-    default y
     depends on ARM_GIC && TCG

 config ARM_GIC_KVM
     bool
-    default y
     depends on ARM_GIC && KVM

 config XICS

?

At least this seems to fix the the migration-test when compiling with 
--without-default-devices.

 Thomas