Re: [PATCH v2] xen/arm: fix the build error for GIC on ARM64 QEMU Platform

[Julien Grall <julien@xxxxxxx>]

Hi,

On 24/12/2021 13:24, Dongjiu Geng wrote:
> when enable CONFIG_NEW_VGIC in ARM64 QEMU Platform, it will build failed.
> so fix it and make it can select GICV2.
As I said in v1, last time I checked QEMU was only able to support 
virtualization with GICv3. This is why we added a depends on.
If you want to remove it, then I think you ought to explain in the 
commit message why this is fine. A pointer to the commit or a QEMU 
version used would be useful.
> Signed-off-by: Dongjiu Geng <gengdongjiu1@xxxxxxxxx>
> ---
> $ make dist-xen XEN_TARGET_ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- -j10
> make -C xen install
> make[1]: Entering directory 
> '/home/workspace/gengdongjiu/old_machine/XEN/xen/xen'
> make -f /home/workspace/gengdongjiu/old_machine/XEN/xen/xen/tools/kconfig/Makefile.kconfig 
> ARCH=arm64 SRCARCH=arm HOSTCC="gcc" HOSTCXX="g++" syncconfig
> make[2]: Entering directory 
> '/home/workspace/gengdongjiu/old_machine/XEN/xen/xen'
> gcc -Wp,-MD,tools/kconfig/.conf.o.d      -c -o tools/kconfig/conf.o 
> tools/kconfig/conf.c
> gcc -Wp,-MD,tools/kconfig/.confdata.o.d      -c -o tools/kconfig/confdata.o 
> tools/kconfig/confdata.c
> gcc -Wp,-MD,tools/kconfig/.expr.o.d      -c -o tools/kconfig/expr.o 
> tools/kconfig/expr.c
> flex -otools/kconfig/lexer.lex.c -L tools/kconfig/lexer.l
> bison -o tools/kconfig/parser.tab.c --defines=tools/kconfig/parser.tab.h -t -l 
> tools/kconfig/parser.y
> gcc -Wp,-MD,tools/kconfig/.preprocess.o.d      -c -o tools/kconfig/preprocess.o 
> tools/kconfig/preprocess.c
> gcc -Wp,-MD,tools/kconfig/.symbol.o.d      -c -o tools/kconfig/symbol.o 
> tools/kconfig/symbol.c
> gcc -Wp,-MD,tools/kconfig/.lexer.lex.o.d     -I 
> /home/workspace/gengdongjiu/old_machine/XEN/xen/xen/tools/kconfig -c -o 
> tools/kconfig/lexer.lex.o tools/kconfig/lexer.lex.c
> gcc -Wp,-MD,tools/kconfig/.parser.tab.o.d     -I 
> /home/workspace/gengdongjiu/old_machine/XEN/xen/xen/tools/kconfig -c -o 
> tools/kconfig/parser.tab.o tools/kconfig/parser.tab.c
> gcc  -o tools/kconfig/conf tools/kconfig/conf.o tools/kconfig/confdata.o 
> tools/kconfig/expr.o tools/kconfig/lexer.lex.o tools/kconfig/parser.tab.o 
> tools/kconfig/preprocess.o tools/kconfig/symbol.o
> tools/kconfig/conf  --syncconfig Kconfig
>
> WARNING: unmet direct dependencies detected for GICV3
>    Depends on [n]: ARM_64 [=y] && !NEW_VGIC [=y]
>    Selected by [y]:
>    - QEMU [=y] && <choice> && ARM_64 [=y]
>
> WARNING: unmet direct dependencies detected for GICV3
>    Depends on [n]: ARM_64 [=y] && !NEW_VGIC [=y]
>    Selected by [y]:
>    - QEMU [=y] && <choice> && ARM_64 [=y]
>
> WARNING: unmet direct dependencies detected for GICV3
>    Depends on [n]: ARM_64 [=y] && !NEW_VGIC [=y]
>    Selected by [y]:
>    - QEMU [=y] && <choice> && ARM_64 [=y]
> make[2]: Leaving directory '/home/workspace/gengdongjiu/old_machine/XEN/xen/xen'
> make -f Rules.mk _install
> make[2]: Entering directory 
> '/home/workspace/gengdongjiu/old_machine/XEN/xen/xen'
> ---
>   xen/arch/arm/Kconfig           | 5 +++--
>   xen/arch/arm/platforms/Kconfig | 1 -
>   2 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig
> index ecfa6822e4..373c698018 100644
> --- a/xen/arch/arm/Kconfig
> +++ b/xen/arch/arm/Kconfig
The change in arch/arm/Kconfig is not really related to this patch. 
Technically the part in platforms/Kconfig is sufficient. I still think 
the change is good to have but it should be in a separate patch.
> @@ -35,7 +35,7 @@ config ACPI
>   
>   config GICV3
>         bool "GICv3 driver"
> -       depends on ARM_64 && !NEW_VGIC
> +       depends on ARM_64
>         default y
>         ---help---
>   
> @@ -44,13 +44,14 @@ config GICV3
>   
>   config HAS_ITS
>           bool "GICv3 ITS MSI controller support (UNSUPPORTED)" if UNSUPPORTED
> -        depends on GICV3 && !NEW_VGIC
> +        depends on GICV3
>   
>   config HVM
>           def_bool y
>   
>   config NEW_VGIC
>         bool "Use new VGIC implementation"
> +       depends on !GICV3
>         ---help---
>   
>   	This is an alternative implementation of the ARM GIC interrupt
> diff --git a/xen/arch/arm/platforms/Kconfig b/xen/arch/arm/platforms/Kconfig
> index c93a6b2756..6d3ee99456 100644
> --- a/xen/arch/arm/platforms/Kconfig
> +++ b/xen/arch/arm/platforms/Kconfig
> @@ -15,7 +15,6 @@ config ALL_PLAT
>   config QEMU
>         bool "QEMU aarch virt machine support"
>         depends on ARM_64
> -       select GICV3
>         select HAS_PL011
>         ---help---
>         Enable all the required drivers for QEMU aarch64 virt emulated
Cheers,

--
Julien Grall