[PATCH v2 0/3] target/arm: disable-tcg and without-default-devices fixes

[PATCH v2 0/3] target/arm: disable-tcg and without-default-devices fixes

[Fabiano Rosas]

Since v1:

Used the 'select if TCG' pattern for both build issues.

We don't want to use imply for semihosting because we'd need to
unpoison* CONFIG_SEMIHOSTING and include CONFIG_DEVICES from helper.c
when building with '--enable-tcg --without-default-devices'.

*- I see the config at build/config-poison.h but the compiler does not
   complain about the usage. It just gets ignored. Any idea why?

CI run: https://gitlab.com/farosas/qemu/-/pipelines/857704454

v1:
https://lore.kernel.org/r/20230503193833.29047-1-farosas@suse.de

Here's the fix for the cdrom test failure that we discussed in the
list, plus 2 fixes for the ---without-default-devices build.

When I moved the boards CONFIGs from default.mak to Kconfig, it became
possible (due to --without-default-devices) to disable the CONFIGs for
all the boards that require ARM_V7M. That breaks the build because
ARM_V7M is required to be always set.

Fabiano Rosas (3):
  target/arm: Select SEMIHOSTING when using TCG
  target/arm: Select CONFIG_ARM_V7M when TCG is enabled
  tests/qtest: Don't run cdrom tests if no accelerator is present

 target/arm/Kconfig       | 9 ++-------
 tests/qtest/cdrom-test.c | 5 +++++
 2 files changed, 7 insertions(+), 7 deletions(-)

-- 
2.35.3

[PATCH v2 1/3] target/arm: Select SEMIHOSTING when using TCG

[Fabiano Rosas]

Semihosting has been made a 'default y' entry in Kconfig, which does
not work because when building --without-default-devices, the
semihosting code would not be available.

Make semihosting unconditional when TCG is present.

Fixes: 29d9efca16 ("arm/Kconfig: Do not build TCG-only boards on a KVM-only build")
Signed-off-by: Fabiano Rosas <farosas@suse.de>
---
 target/arm/Kconfig | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/target/arm/Kconfig b/target/arm/Kconfig
index 39f05b6420..3fffdcb61b 100644
--- a/target/arm/Kconfig
+++ b/target/arm/Kconfig
@@ -1,13 +1,7 @@
 config ARM
     bool
+    select ARM_COMPATIBLE_SEMIHOSTING if TCG
 
 config AARCH64
     bool
     select ARM
-
-# This config exists just so we can make SEMIHOSTING default when TCG
-# is selected without also changing it for other architectures.
-config ARM_SEMIHOSTING
-    bool
-    default y if TCG && ARM
-    select ARM_COMPATIBLE_SEMIHOSTING
-- 
2.35.3

[PATCH v2 2/3] target/arm: Select CONFIG_ARM_V7M when TCG is enabled

[Fabiano Rosas]

We cannot allow this config to be disabled at the moment as not all of
the relevant code is protected by it.

Commit 29d9efca16 ("arm/Kconfig: Do not build TCG-only boards on a
KVM-only build") moved the CONFIGs of several boards to Kconfig, so it
is now possible that nothing selects ARM_V7M (e.g. when doing a
--without-default-devices build).

Return the CONFIG_ARM_V7M entry to a state where it is always selected
whenever TCG is available.

Fixes: 29d9efca16 ("arm/Kconfig: Do not build TCG-only boards on a KVM-only build")
Signed-off-by: Fabiano Rosas <farosas@suse.de>
---
 target/arm/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/target/arm/Kconfig b/target/arm/Kconfig
index 3fffdcb61b..5947366f6e 100644
--- a/target/arm/Kconfig
+++ b/target/arm/Kconfig
@@ -1,6 +1,7 @@
 config ARM
     bool
     select ARM_COMPATIBLE_SEMIHOSTING if TCG
+    select ARM_V7M if TCG
 
 config AARCH64
     bool
-- 
2.35.3

[PATCH v2 3/3] tests/qtest: Don't run cdrom tests if no accelerator is present

[Fabiano Rosas]

On a build configured with: --disable-tcg --enable-xen it is possible
to produce a QEMU binary with no TCG nor KVM support. Skip the test if
that's the case.

Fixes: 0c1ae3ff9d ("tests/qtest: Fix tests when no KVM or TCG are present")
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Fabiano Rosas <farosas@suse.de>
---
 tests/qtest/cdrom-test.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/tests/qtest/cdrom-test.c b/tests/qtest/cdrom-test.c
index 26a2400181..09655e6ff0 100644
--- a/tests/qtest/cdrom-test.c
+++ b/tests/qtest/cdrom-test.c
@@ -205,6 +205,11 @@ int main(int argc, char **argv)
 
     g_test_init(&argc, &argv, NULL);
 
+    if (!qtest_has_accel("tcg") && !qtest_has_accel("kvm")) {
+        g_test_skip("No KVM or TCG accelerator available");
+        return 0;
+    }
+
     if (exec_genisoimg(genisocheck)) {
         /* genisoimage not available - so can't run tests */
         return g_test_run();
-- 
2.35.3

Re: [PATCH v2 3/3] tests/qtest: Don't run cdrom tests if no accelerator is present

[Thomas Huth]

On 05/05/2023 14.35, Fabiano Rosas wrote:
> On a build configured with: --disable-tcg --enable-xen it is possible
> to produce a QEMU binary with no TCG nor KVM support. Skip the test if
> that's the case.
> 
> Fixes: 0c1ae3ff9d ("tests/qtest: Fix tests when no KVM or TCG are present")
> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
> Signed-off-by: Fabiano Rosas <farosas@suse.de>
> ---
>   tests/qtest/cdrom-test.c | 5 +++++
>   1 file changed, 5 insertions(+)
> 
> diff --git a/tests/qtest/cdrom-test.c b/tests/qtest/cdrom-test.c
> index 26a2400181..09655e6ff0 100644
> --- a/tests/qtest/cdrom-test.c
> +++ b/tests/qtest/cdrom-test.c
> @@ -205,6 +205,11 @@ int main(int argc, char **argv)
>   
>       g_test_init(&argc, &argv, NULL);
>   
> +    if (!qtest_has_accel("tcg") && !qtest_has_accel("kvm")) {
> +        g_test_skip("No KVM or TCG accelerator available");
> +        return 0;
> +    }

You only nee to skip the test if running with x86 or s390x, all other 
targets use only "-accel qtest" IIRC, so those shoul be fine.

  Thomas