Re: [PATCH 04/15] KVM: arm64: Move host SME/SVE tracking flags to host data

[Marc Zyngier <maz@kernel.org>]

On Fri, 08 Nov 2024 22:24:08 +0000,
Oliver Upton <oliver.upton@linux.dev> wrote:
> 
> The SME/SVE state tracking flags have no business in the vCPU. Move them
> to kvm_host_data.
> 
> Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
> ---
>  arch/arm64/include/asm/kvm_host.h | 25 ++++++++++++-------------
>  arch/arm64/kvm/fpsimd.c           | 12 ++++++------
>  2 files changed, 18 insertions(+), 19 deletions(-)
> 
> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
> index 07da4129f1d1..cf5cdc468aa4 100644
> --- a/arch/arm64/include/asm/kvm_host.h
> +++ b/arch/arm64/include/asm/kvm_host.h
> @@ -610,8 +610,10 @@ struct cpu_sve_state {
>   * field.
>   */
>  struct kvm_host_data {
> -#define KVM_HOST_DATA_FLAG_HAS_SPE	0
> -#define KVM_HOST_DATA_FLAG_HAS_TRBE	1
> +#define KVM_HOST_DATA_FLAG_HAS_SPE			0
> +#define KVM_HOST_DATA_FLAG_HAS_TRBE			1
> +#define KVM_HOST_DATA_FLAG_HOST_SVE_ENABLED		2
> +#define KVM_HOST_DATA_FLAG_HOST_SME_ENABLED		3
>  	unsigned long flags;
>  
>  	struct kvm_cpu_context host_ctxt;
> @@ -916,22 +918,18 @@ struct kvm_vcpu_arch {
>  /* Guest debug is live */
>  #define DEBUG_DIRTY		__vcpu_single_flag(iflags, BIT(4))
>  
> -/* SVE enabled for host EL0 */
> -#define HOST_SVE_ENABLED	__vcpu_single_flag(sflags, BIT(0))
> -/* SME enabled for EL0 */
> -#define HOST_SME_ENABLED	__vcpu_single_flag(sflags, BIT(1))
>  /* Physical CPU not in supported_cpus */
> -#define ON_UNSUPPORTED_CPU	__vcpu_single_flag(sflags, BIT(2))
> +#define ON_UNSUPPORTED_CPU	__vcpu_single_flag(sflags, BIT(0))
>  /* WFIT instruction trapped */
> -#define IN_WFIT			__vcpu_single_flag(sflags, BIT(3))
> +#define IN_WFIT			__vcpu_single_flag(sflags, BIT(1))
>  /* vcpu system registers loaded on physical CPU */
> -#define SYSREGS_ON_CPU		__vcpu_single_flag(sflags, BIT(4))
> +#define SYSREGS_ON_CPU		__vcpu_single_flag(sflags, BIT(2))
>  /* Software step state is Active-pending */
> -#define DBG_SS_ACTIVE_PENDING	__vcpu_single_flag(sflags, BIT(5))
> +#define DBG_SS_ACTIVE_PENDING	__vcpu_single_flag(sflags, BIT(3))
>  /* PMUSERENR for the guest EL0 is on physical CPU */
> -#define PMUSERENR_ON_CPU	__vcpu_single_flag(sflags, BIT(6))
> +#define PMUSERENR_ON_CPU	__vcpu_single_flag(sflags, BIT(4))
>  /* WFI instruction trapped */
> -#define IN_WFI			__vcpu_single_flag(sflags, BIT(7))
> +#define IN_WFI			__vcpu_single_flag(sflags, BIT(5))
>  
>  
>  /* Pointer to the vcpu's SVE FFR for sve_{save,load}_state() */
> @@ -1314,7 +1312,8 @@ DECLARE_KVM_HYP_PER_CPU(struct kvm_host_data, kvm_host_data);
>  	(test_bit(KVM_HOST_DATA_FLAG_##flag, host_data_ptr(flags)))
>  #define host_data_set_flag(flag)					\
>  	(set_bit(KVM_HOST_DATA_FLAG_##flag, host_data_ptr(flags)))
> -
> +#define host_data_clear_flag(flag)					\
> +	(clear_bit(KVM_HOST_DATA_FLAG_##flag, host_data_ptr(flags)))

nit: move the flag-clearing primitive to the patch that introduces the
two others for consistency, and drop the brackets surrounding the
set/clear statements.

Otherwise, this is a pretty nice cleanup.

	M.

-- 
Without deviation from the norm, progress is not possible.