Re: [PATCH v6 26/33] KVM: s390: arm64: Introduce host definitions

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] The vcpu flag wrapper macros (`_vcpu_get_flag`, `_vcpu_set_flag`, etc.) are syntactically broken and will cause build failures if instantiated.
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--- Patch [26]: [PATCH v6 26/33] KVM: s390: arm64: Introduce host definitions ---
commit 9d09eb59e082ce9c0d035d93867a0ac53fc503a3
Author: Steffen Eiden <seiden@linux.ibm.com>

KVM: s390: arm64: Introduce host definitions

This commit adds basic definitions required by the ARM on s390 KVM host.
It introduces struct kvm*arch definitions and various defines needed to
run arm64 guests, selecting the new header variant if KVM_S390_ARM64 is
defined.

> diff --git a/arch/s390/include/asm/kvm_host_arm64.h b/arch/s390/include/asm/kvm_host_arm64.h
> new file mode 100644
> index 0000000000000..8088409bb0411
> --- /dev/null
> +++ b/arch/s390/include/asm/kvm_host_arm64.h

[ ... ]

> +#define _vcpu_get_flag(v, flagset, ...)	\
> +	__vcpu_get_flag(&(v)->arch.flagset, __VA_ARGS__)
> +#define _vcpu_set_flag(v, flagset, ...)	\
> +	__vcpu_set_flag(&(v)->arch.flagset, __VA_ARGS__)
> +#define _vcpu_clear_flag(v, flagset, ...)	\
> +	__vcpu_clear_flag(&(v)->arch.flagset, __VA_ARGS__)
> +#define _vcpu_test_and_clear_flag(v, flagset, ...)	\
> +	__vcpu_test_and_clear_flag(&(v)->arch.flagset, __VA_ARGS__)

[Severity: Low]
Will these wrapper macros cause a build failure when instantiated?

Looking at __vcpu_get_flag() and the related macros from the shared arm64
headers, they expect exactly four arguments: v, flagset, f, and m. 

In these wrappers, we pass &(v)->arch.flagset as the first argument and
__VA_ARGS__ as the remaining arguments. Since standard flag constants usually
expand to two arguments (for example, BIT(0), BIT(0) for f and m), this
invocation only provides three arguments in total instead of the required four.

Does this need an additional argument or a different macro structure to
resolve the arity mismatch?

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Sashiko AI review · https://sashiko.dev/#/patchset/20260812153631.3376090-1-seiden@linux.ibm.com?part=26