Re: [PATCH] KVM: x86: Unify L1TF flushing under per-CPU variable

[Brendan Jackman]

On Tue Oct 14, 2025 at 7:24 AM UTC, kernel test robot wrote:
> Hi Brendan,
>
> kernel test robot noticed the following build errors:
>
> [auto build test ERROR on 6b36119b94d0b2bb8cea9d512017efafd461d6ac]
>
> url:    https://github.com/intel-lab-lkp/linux/commits/Brendan-Jackman/KVM-x86-Unify-L1TF-flushing-under-per-CPU-variable/20251013-235118
> base:   6b36119b94d0b2bb8cea9d512017efafd461d6ac
> patch link:    https://lore.kernel.org/r/20251013-b4-l1tf-percpu-v1-1-d65c5366ea1a%40google.com
> patch subject: [PATCH] KVM: x86: Unify L1TF flushing under per-CPU variable
> config: x86_64-rhel-9.4 (https://download.01.org/0day-ci/archive/20251014/202510141438.OMSBOz6R-lkp@xxxxxxxxx/config)
> compiler: gcc-14 (Debian 14.2.0-19) 14.2.0
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251014/202510141438.OMSBOz6R-lkp@xxxxxxxxx/reproduce)
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@xxxxxxxxx>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202510141438.OMSBOz6R-lkp@xxxxxxxxx/
>
> All errors (new ones prefixed by >>):
>
>>> arch/x86/coco/tdx/tdx.c:471:12: error: conflicting types for 'read_msr'; have 'int(struct pt_regs *, struct ve_info *)'
>      471 | static int read_msr(struct pt_regs *regs, struct ve_info *ve)
>          |            ^~~~~~~~
>    In file included from arch/x86/include/asm/idtentry.h:15,
>                     from arch/x86/include/asm/traps.h:9,
>                     from arch/x86/coco/tdx/tdx.c:20:
>    arch/x86/include/asm/kvm_host.h:2320:29: note: previous definition of 'read_msr' with type 'long unsigned int(long unsigned int)'
>     2320 | static inline unsigned long read_msr(unsigned long msr)
>          |                             ^~~~~~~~

Yeah this is essentially just another symptom of the kvm_host.h abuse Sean
pointed out.