Re: [PATCH] kvm: drop work around for kernel header typo.

[Peter Maydell]

On Mon, 7 Feb 2022 at 12:35, Nan Wang <wangnan.light@bytedance.com> wrote:
>
> From: "wangnan.light" <wangnan.light@bytedance.com>
>
> Kernel header once had a typo(linux commit caa057a2cad6), qemu have to work 
> around it with
> hardcode macro(qemu commit 6f131f13e68d). Now kernel fix it(linux commit 
> 766d3571d8e5),
> so we can remove redundant code.

The other relevant git commit hash worth mentioning here is
QEMU commit 77d361b13c19f, which is where we updated our copy of
the kernel headers to a version that included that fix. You
might also mention when these fixes happened, which was back in 2018.

> Signed-off-by: wangnan.light <wangnan.light@bytedance.com>
> ---
>  target/i386/kvm/kvm.c | 4 ----
>  1 file changed, 4 deletions(-)
>
> diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
> index 2c8feb4a6f..f65ed37591 100644
> --- a/target/i386/kvm/kvm.c
> +++ b/target/i386/kvm/kvm.c
> @@ -2403,10 +2403,6 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
>          int disable_exits = kvm_check_extension(s, 
> KVM_CAP_X86_DISABLE_EXITS);
>          int ret;
>
> -/* Work around for kernel header with a typo. TODO: fix header and drop. */
> -#if defined(KVM_X86_DISABLE_EXITS_HTL) && !defined(KVM_X86_DISABLE_EXITS_HLT)
> -#define KVM_X86_DISABLE_EXITS_HLT KVM_X86_DISABLE_EXITS_HTL
> -#endif
>          if (disable_exits) {
>              disable_exits &= (KVM_X86_DISABLE_EXITS_MWAIT |
>                                KVM_X86_DISABLE_EXITS_HLT |

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

(Side note, I'm surprised that kernel fix was allowed in -- it breaks any
userspace code that was relying on the typo'd #define name, which
would have been easily avoidable by just defining both names. But that
was years ago now, so it's done...)

thanks
-- PMM