Re: [PATCH] KVM: Remove subtle "struct kvm_stats_desc" pseudo-overlay
From: Christian Borntraeger <borntraeger@linux.ibm.com>
Date: 2025-12-08 10:33:01
Also in:
kvm, kvm-riscv, kvmarm, linux-arm-kernel, linux-mips, linux-riscv, lkml, loongarch
Am 06.12.25 um 00:26 schrieb Sean Christopherson:
Remove KVM's internal pseudo-overlay of kvm_stats_desc, which subtly aliases the flexible name[] in the uAPI definition with a fixed-size array of the same name. The unusual embedded structure results in compiler warnings due to -Wflex-array-member-not-at-end, and also necessitates an extra level of dereferencing in KVM. To avoid the "overlay", define the uAPI structure to have a fixed-size name when building for the kernel. Opportunistically clean up the indentation for the stats macros, and replace spaces with tabs. No functional change intended. Reported-by: Gustavo A. R. Silva <gustavoars@kernel.org> Closes: https://lore.kernel.org/all/aPfNKRpLfhmhYqfP@kspp (local) Signed-off-by: Sean Christopherson <seanjc@google.com>
Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com> [..]
quoted hunk ↗ jump to hunk
--- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h@@ -14,6 +14,10 @@ #include <linux/ioctl.h> #include <asm/kvm.h> +#ifdef __KERNEL__ +#include <linux/kvm_types.h> +#endif + #define KVM_API_VERSION 12 /*@@ -1579,7 +1583,11 @@ struct kvm_stats_desc { __u16 size; __u32 offset; __u32 bucket_size; +#ifdef __KERNEL__ + char name[KVM_STATS_NAME_SIZE]; +#else char name[]; +#endif };
Not sure if we need a comment here or not. Maybe git blame is good enough.