Re: [PATCH 5/5] HPET interaction with in-kernel PIT (v6)

[Avi Kivity <avi@redhat.com>]

Beth Kon wrote:
> Signed-off-by: Beth Kon <eak@us.ibm.com>
>
>   

Please write a few words on what this patch does and why.

> ---
>  arch/x86/include/asm/kvm.h |    1 +
>  arch/x86/kvm/i8254.c       |   24 +++++++++++++++++++-----
>  arch/x86/kvm/i8254.h       |    3 ++-
>  arch/x86/kvm/x86.c         |    5 ++++-
>  4 files changed, 26 insertions(+), 7 deletions(-)
>
> diff --git a/arch/x86/include/asm/kvm.h b/arch/x86/include/asm/kvm.h
> index 708b9c3..3c44923 100644
> --- a/arch/x86/include/asm/kvm.h
> +++ b/arch/x86/include/asm/kvm.h
> @@ -235,6 +235,7 @@ struct kvm_guest_debug_arch {
>  
>  struct kvm_pit_state {
>  	struct kvm_pit_channel_state channels[3];
> +	u8 hpet_legacy_mode;
>  };
>   

This changes the ABI, breaking older binaries running on newer kernels, 
or newer binaries running on older kernels.

> @@ -340,10 +340,20 @@ static void pit_load_count(struct kvm *kvm, int channel, u32 val)
>  	}
>  }
>  
> -void kvm_pit_load_count(struct kvm *kvm, int channel, u32 val)
> +void kvm_pit_load_count(struct kvm *kvm, int channel, u32 val, int hpet_legacy_start)
>  {
> +	u8 saved_mode;
>  	mutex_lock(&kvm->arch.vpit->pit_state.lock);
> -	pit_load_count(kvm, channel, val);
> +	if (hpet_legacy_start) {
> +		/* save existing mode for later reenablement */
> +		saved_mode = kvm->arch.vpit->pit_state.channels[0].mode;
> +		kvm->arch.vpit->pit_state.channels[0].mode = 0xff; /* disable timer */
> +		pit_load_count(kvm, channel, val);
> +		kvm->arch.vpit->pit_state.channels[0].mode = saved_mode;
> +	} else {
> +			if (!(channel == 0 && kvm->arch.vpit->pit_state.hpet_legacy_mode))
> +			pit_load_count(kvm, channel, val);
>   

Overindented.



-- 
error compiling committee.c: too many arguments to function