[PATCH 07/18] KVM: arm64: Move vcpu configuration flags into their own set

[Reiji Watanabe]

On Sat, May 28, 2022 at 4:38 AM Marc Zyngier <maz at kernel.org> wrote:
>
> The KVM_ARM64_{GUEST_HAS_SVE,VCPU_SVE_FINALIZED,GUEST_HAS_PTRAUTH}
> flags are purely configuration flags. Once set, they are never cleared,
> but evaluated all over the code base.
>
> Move these three flags into the configuration set in one go, using
> the new accessors, and take this opportunity to drop the KVM_ARM64_
> prefix which doesn't provide any help.
>
> Signed-off-by: Marc Zyngier <maz at kernel.org>
> ---
>  arch/arm64/include/asm/kvm_host.h | 17 ++++++++++-------
>  arch/arm64/kvm/reset.c            |  6 +++---
>  2 files changed, 13 insertions(+), 10 deletions(-)
>
> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
> index c9dd0d4e22f2..2b8f1265eade 100644
> --- a/arch/arm64/include/asm/kvm_host.h
> +++ b/arch/arm64/include/asm/kvm_host.h
> @@ -459,6 +459,13 @@ struct kvm_vcpu_arch {
>  #define __flag_unpack(_set, _f, _m)    _f
>  #define vcpu_flag_unpack(...)          __flag_unpack(__VA_ARGS__)
>
> +/* SVE exposed to guest */
> +#define GUEST_HAS_SVE          __vcpu_single_flag(cflags, BIT(0))
> +/* SVE config completed */
> +#define VCPU_SVE_FINALIZED     __vcpu_single_flag(cflags, BIT(1))
> +/* PTRAUTH exposed to guest */
> +#define GUEST_HAS_PTRAUTH      __vcpu_single_flag(cflags, BIT(2))
> +
>
>  /* Pointer to the vcpu's SVE FFR for sve_{save,load}_state() */
>  #define vcpu_sve_pffr(vcpu) (kern_hyp_va((vcpu)->arch.sve_state) +     \
> @@ -483,9 +490,6 @@ struct kvm_vcpu_arch {
>  /* vcpu_arch flags field values: */
>  #define KVM_ARM64_DEBUG_DIRTY          (1 << 0)
>  #define KVM_ARM64_HOST_SVE_ENABLED     (1 << 4) /* SVE enabled for EL0 */
> -#define KVM_ARM64_GUEST_HAS_SVE                (1 << 5) /* SVE exposed to guest */
> -#define KVM_ARM64_VCPU_SVE_FINALIZED   (1 << 6) /* SVE config completed */
> -#define KVM_ARM64_GUEST_HAS_PTRAUTH    (1 << 7) /* PTRAUTH exposed to guest */
>  #define KVM_ARM64_PENDING_EXCEPTION    (1 << 8) /* Exception pending */
>  /*
>   * Overlaps with KVM_ARM64_EXCEPT_MASK on purpose so that it can't be
> @@ -522,13 +526,13 @@ struct kvm_vcpu_arch {
>                                  KVM_GUESTDBG_SINGLESTEP)
>
>  #define vcpu_has_sve(vcpu) (system_supports_sve() &&                   \
> -                           ((vcpu)->arch.flags & KVM_ARM64_GUEST_HAS_SVE))
> +                           vcpu_get_flag((vcpu), GUEST_HAS_SVE))

Minor nit: The parentheses around the vcpu above would be unnecessary.
(as was omitted for vcpu_has_ptrauth/kvm_arm_vcpu_sve_finalized)

Reviewed-by: Reiji Watanabe <reijiw at google.com>

The new infrastructure for those flags looks nice.

Thanks!
Reiji



>
>  #ifdef CONFIG_ARM64_PTR_AUTH
>  #define vcpu_has_ptrauth(vcpu)                                         \
>         ((cpus_have_final_cap(ARM64_HAS_ADDRESS_AUTH) ||                \
>           cpus_have_final_cap(ARM64_HAS_GENERIC_AUTH)) &&               \
> -        (vcpu)->arch.flags & KVM_ARM64_GUEST_HAS_PTRAUTH)
> +         vcpu_get_flag(vcpu, GUEST_HAS_PTRAUTH))
>  #else
>  #define vcpu_has_ptrauth(vcpu)         false
>  #endif
> @@ -885,8 +889,7 @@ void kvm_init_protected_traps(struct kvm_vcpu *vcpu);
>  int kvm_arm_vcpu_finalize(struct kvm_vcpu *vcpu, int feature);
>  bool kvm_arm_vcpu_is_finalized(struct kvm_vcpu *vcpu);
>
> -#define kvm_arm_vcpu_sve_finalized(vcpu) \
> -       ((vcpu)->arch.flags & KVM_ARM64_VCPU_SVE_FINALIZED)
> +#define kvm_arm_vcpu_sve_finalized(vcpu) vcpu_get_flag(vcpu, VCPU_SVE_FINALIZED)
>
>  #define kvm_has_mte(kvm)                                       \
>         (system_supports_mte() &&                               \
> diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
> index 6c70c6f61c70..0e08fbe68715 100644
> --- a/arch/arm64/kvm/reset.c
> +++ b/arch/arm64/kvm/reset.c
> @@ -81,7 +81,7 @@ static int kvm_vcpu_enable_sve(struct kvm_vcpu *vcpu)
>          * KVM_REG_ARM64_SVE_VLS.  Allocation is deferred until
>          * kvm_arm_vcpu_finalize(), which freezes the configuration.
>          */
> -       vcpu->arch.flags |= KVM_ARM64_GUEST_HAS_SVE;
> +       vcpu_set_flag(vcpu, GUEST_HAS_SVE);
>
>         return 0;
>  }
> @@ -120,7 +120,7 @@ static int kvm_vcpu_finalize_sve(struct kvm_vcpu *vcpu)
>         }
>
>         vcpu->arch.sve_state = buf;
> -       vcpu->arch.flags |= KVM_ARM64_VCPU_SVE_FINALIZED;
> +       vcpu_set_flag(vcpu, VCPU_SVE_FINALIZED);
>         return 0;
>  }
>
> @@ -177,7 +177,7 @@ static int kvm_vcpu_enable_ptrauth(struct kvm_vcpu *vcpu)
>             !system_has_full_ptr_auth())
>                 return -EINVAL;
>
> -       vcpu->arch.flags |= KVM_ARM64_GUEST_HAS_PTRAUTH;
> +       vcpu_set_flag(vcpu, GUEST_HAS_PTRAUTH);
>         return 0;
>  }
>
> --
> 2.34.1
>
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