Re: [PATCH v3 17/19] hw/arm: Automatically select the 'virt' machine on KVM

[Philippe Mathieu-Daudé]

On 10/1/20 9:38 AM, Paolo Bonzini wrote:
> On 29/09/20 22:36, Philippe Mathieu-Daudé wrote:
>> Yes, the problem if I don't restrict to KVM, when
>> using the Xen accelerator odd things occur
>> (using configure --enable-xen --disable-tcg --disable-kvm):
>>
>> Compiling C object libqemu-i386-softmmu.fa.p/hw_cpu_a15mpcore.c.o
>> hw/cpu/a15mpcore.c:28:10: fatal error: kvm_arm.h: No such file or directory
>>
>> See
>> https://wiki.xenproject.org/wiki/Xen_ARM_with_Virtualization_Extensions#Use_of_qemu-system-i386_on_ARM
> 
> I don't understand.  Is Xen adding CONFIG_ARM_VIRT=y to
> default-configs/i386-softmmu.mak??

No, this is when using:

 config ARM_VIRT
     bool
+    default y

I had the understanding devices in hw/$BASEARCH would be only
included for $ARCH, but I was wrong, any arch kconfig-include
the devices of the other archs.

I tried the following diff which doesn't build because various
devices in *non*-archdep folders use arch-specific Kconfig values:

-- >8 --
diff --git a/meson.build b/meson.build
index 9ab5d514d7..cfe19d0007 100644
--- a/meson.build
+++ b/meson.build
@@ -575,6 +575,7 @@ foreach target : target_dirs
     if fs.is_file(target_kconfig)
       minikconf_input += [target_kconfig]
     endif
+    minikconf_input += 'hw' / config_target['TARGET_BASE_ARCH'] / 'Kconfig'
     config_devices_mak = configure_file(
       input: minikconf_input,
       output: config_devices_mak,
diff --git a/hw/Kconfig b/hw/Kconfig
index 4de1797ffd..64c120175a 100644
--- a/hw/Kconfig
+++ b/hw/Kconfig
@@ -41,29 +41,29 @@ source vfio/Kconfig
 source watchdog/Kconfig

 # arch Kconfig
-source arm/Kconfig
-source alpha/Kconfig
-source avr/Kconfig
-source cris/Kconfig
-source hppa/Kconfig
-source i386/Kconfig
-source lm32/Kconfig
-source m68k/Kconfig
-source microblaze/Kconfig
-source mips/Kconfig
-source moxie/Kconfig
-source nios2/Kconfig
-source openrisc/Kconfig
-source ppc/Kconfig
-source riscv/Kconfig
-source rx/Kconfig
-source s390x/Kconfig
-source sh4/Kconfig
-source sparc/Kconfig
-source sparc64/Kconfig
-source tricore/Kconfig
-source unicore32/Kconfig
-source xtensa/Kconfig

 # Symbols used by multiple targets
 config TEST_DEVICES
---

> 
> (By the way, there are duplicate Kconfig symbols between target/arm and
> hw/cpu, they could/should be removed from target/arm).

I'd rather define Kconfig entry where the model is, so in this case
keep them defined in hw/cpu/Kconfig and remove dup entries from
hw/arm/Kconfig (if Peter is OK with that).

> 
> Paolo
>