Re: [PATCH v4 03/30] UAPI: x86: Move pvclock-abi to UAPI for x86 platforms

[Dongli Zhang <dongli.zhang@xxxxxxxxxx>]

I have encountered below build warning.

Perhaps it is because of PATCH 03?

In file included from ./include/linux/types.h:5,
                 from ./arch/x86/include/uapi/asm/pvclock-abi.h:5,
                 from ./arch/x86/include/asm/xen/interface.h:197,
                 from ./include/xen/interface/xen.h:13,
                 from <command-line>:
./include/uapi/linux/types.h:10:2: warning: #warning "Attempt to use kernel
headers from user space, see https://kernelnewbies.org/KernelHeaders"; [-Wcpp]
   10 | #warning "Attempt to use kernel headers from user space, see
https://kernelnewbies.org/KernelHeaders";
      |  ^~~~~~~
In file included from ./include/linux/types.h:5,
                 from ./arch/x86/include/uapi/asm/pvclock-abi.h:5,
                 from ./arch/x86/include/asm/xen/interface.h:197,
                 from ./include/xen/interface/xen.h:13,
                 from ./include/xen/interface/xenpmu.h:5,
                 from <command-line>:
./include/uapi/linux/types.h:10:2: warning: #warning "Attempt to use kernel
headers from user space, see https://kernelnewbies.org/KernelHeaders"; [-Wcpp]
   10 | #warning "Attempt to use kernel headers from user space, see
https://kernelnewbies.org/KernelHeaders";
      |  ^~~~~~~

Thank you very much!

Dongli Zhang

On 2026-05-09 3:46 PM, David Woodhouse wrote:
> From: Jack Allister <jalliste@xxxxxxxxxx>
> 
> A subsequent commit will provide a new KVM interface for performing a
> fixup/correction of the KVM clock against the reference TSC. The
> KVM_[GS]ET_CLOCK_GUEST API requires a pvclock_vcpu_time_info, as such
> the caller must know about this definition.
> 
> Move the definition to the UAPI folder so that it is exported to
> usermode and also change the type definitions to use the standard for
> UAPI exports.
> 
> Signed-off-by: Jack Allister <jalliste@xxxxxxxxxx>
> Signed-off-by: David Woodhouse <dwmw@xxxxxxxxxxxx>
> Reviewed-by: Paul Durrant <paul@xxxxxxx>
> ---
>  MAINTAINERS                                   |  4 +--
>  arch/x86/include/{ => uapi}/asm/pvclock-abi.h | 27 ++++++++++---------
>  2 files changed, 17 insertions(+), 14 deletions(-)
>  rename arch/x86/include/{ => uapi}/asm/pvclock-abi.h (82%)
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index e0b307b2108c..e49676955c0c 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -14406,7 +14406,7 @@ S:    Supported
>  T:   git git://git.kernel.org/pub/scm/virt/kvm/kvm.git
>  F:   arch/um/include/asm/kvm_para.h
>  F:   arch/x86/include/asm/kvm_para.h
> -F:   arch/x86/include/asm/pvclock-abi.h
> +F:   arch/x86/include/uapi/asm/pvclock-abi.h
>  F:   arch/x86/include/uapi/asm/kvm_para.h
>  F:   arch/x86/kernel/kvm.c
>  F:   arch/x86/kernel/kvmclock.c
> @@ -29087,7 +29087,7 @@ R:    Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
>  L:   xen-devel@xxxxxxxxxxxxxxxxxxxx (moderated for non-subscribers)
>  S:   Supported
>  F:   arch/x86/configs/xen.config
> -F:   arch/x86/include/asm/pvclock-abi.h
> +F:   arch/x86/include/uapi/asm/pvclock-abi.h
>  F:   arch/x86/include/asm/xen/
>  F:   arch/x86/platform/pvh/
>  F:   arch/x86/xen/
> diff --git a/arch/x86/include/asm/pvclock-abi.h 
> b/arch/x86/include/uapi/asm/pvclock-abi.h
> similarity index 82%
> rename from arch/x86/include/asm/pvclock-abi.h
> rename to arch/x86/include/uapi/asm/pvclock-abi.h
> index b9fece5fc96d..6d70cf640362 100644
> --- a/arch/x86/include/asm/pvclock-abi.h
> +++ b/arch/x86/include/uapi/asm/pvclock-abi.h
> @@ -1,6 +1,9 @@
> -/* SPDX-License-Identifier: GPL-2.0 */
> +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
>  #ifndef _ASM_X86_PVCLOCK_ABI_H
>  #define _ASM_X86_PVCLOCK_ABI_H
> +
> +#include <linux/types.h>
> +
>  #ifndef __ASSEMBLER__
>  
>  /*
> @@ -24,20 +27,20 @@
>   */
>  
>  struct pvclock_vcpu_time_info {
> -     u32   version;
> -     u32   pad0;
> -     u64   tsc_timestamp;
> -     u64   system_time;
> -     u32   tsc_to_system_mul;
> -     s8    tsc_shift;
> -     u8    flags;
> -     u8    pad[2];
> +     __u32   version;
> +     __u32   pad0;
> +     __u64   tsc_timestamp;
> +     __u64   system_time;
> +     __u32   tsc_to_system_mul;
> +     __s8    tsc_shift;
> +     __u8    flags;
> +     __u8    pad[2];
>  } __attribute__((__packed__)); /* 32 bytes */
>  
>  struct pvclock_wall_clock {
> -     u32   version;
> -     u32   sec;
> -     u32   nsec;
> +     __u32   version;
> +     __u32   sec;
> +     __u32   nsec;
>  } __attribute__((__packed__));
>  
>  #define PVCLOCK_TSC_STABLE_BIT       (1 << 0)