Re: [PATCH v9 09/30] KVM: arm64: Rename SVE finalization constants to be more general

On Tue, 23 Dec 2025 at 01:22, Mark Brown broonie@kernel.org wrote:

Due to the overlap between SVE and SME vector length configuration created by streaming mode SVE we will finalize both at once. Rename the existing finalization to use _VEC (vector) for the naming to avoid confusion.

Since this includes the userspace API we create an alias KVM_ARM_VCPU_VEC for the existing KVM_ARM_VCPU_SVE capability, existing code which does not enable SME will be unaffected and any SME only code will not need to use SVE constants.

No functional change.

Signed-off-by: Mark Brown broonie@kernel.org

Reviewed-by: Fuad Tabba tabba@google.com

Cheers, /fuad

---

arch/arm64/include/asm/kvm_host.h | 8 +++++--- arch/arm64/include/uapi/asm/kvm.h | 6 ++++++ arch/arm64/kvm/guest.c | 10 +++++----- arch/arm64/kvm/hyp/nvhe/pkvm.c | 2 +- arch/arm64/kvm/reset.c | 20 ++++++++++---------- 5 files changed, 27 insertions(+), 19 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index e6d25db10a6b..0f3d26467bf0 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -988,8 +988,8 @@ struct kvm_vcpu_arch {

/* KVM_ARM_VCPU_INIT completed */ #define VCPU_INITIALIZED __vcpu_single_flag(cflags, BIT(0)) -/* SVE config completed */ -#define VCPU_SVE_FINALIZED __vcpu_single_flag(cflags, BIT(1)) +/* Vector config completed */ +#define VCPU_VEC_FINALIZED __vcpu_single_flag(cflags, BIT(1)) /* pKVM VCPU setup completed */ #define VCPU_PKVM_FINALIZED __vcpu_single_flag(cflags, BIT(2))

@@ -1062,6 +1062,8 @@ struct kvm_vcpu_arch { #define vcpu_has_sve(vcpu) kvm_has_sve((vcpu)->kvm) #endif

+#define vcpu_has_vec(vcpu) vcpu_has_sve(vcpu)

#ifdef CONFIG_ARM64_PTR_AUTH #define vcpu_has_ptrauth(vcpu) \ ((cpus_have_final_cap(ARM64_HAS_ADDRESS_AUTH) || \ @@ -1458,7 +1460,7 @@ struct kvm *kvm_arch_alloc_vm(void); 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_get_flag(vcpu, VCPU_SVE_FINALIZED) +#define kvm_arm_vcpu_vec_finalized(vcpu) vcpu_get_flag(vcpu, VCPU_VEC_FINALIZED)

#define kvm_has_mte(kvm) \ (system_supports_mte() && \ diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h index a792a599b9d6..c67564f02981 100644 --- a/arch/arm64/include/uapi/asm/kvm.h +++ b/arch/arm64/include/uapi/asm/kvm.h @@ -107,6 +107,12 @@ struct kvm_regs { #define KVM_ARM_VCPU_HAS_EL2 7 /* Support nested virtualization */ #define KVM_ARM_VCPU_HAS_EL2_E2H0 8 /* Limit NV support to E2H RES0 */

+/*

• • An alias for _SVE since we finalize VL configuration for both SVE and SME
• • simultaneously.
• */

+#define KVM_ARM_VCPU_VEC KVM_ARM_VCPU_SVE

struct kvm_vcpu_init { __u32 target; __u32 features[7]; diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c index 1c87699fd886..d15aa2da1891 100644 --- a/arch/arm64/kvm/guest.c +++ b/arch/arm64/kvm/guest.c @@ -342,7 +342,7 @@ static int set_sve_vls(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) if (!vcpu_has_sve(vcpu)) return -ENOENT;

•   if (kvm_arm_vcpu_sve_finalized(vcpu))
  

•   if (kvm_arm_vcpu_vec_finalized(vcpu))
            return -EPERM; /* too late! */
  
    if (WARN_ON(vcpu->arch.sve_state))
  

@@ -497,7 +497,7 @@ static int get_sve_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) if (ret) return ret;

•   if (!kvm_arm_vcpu_sve_finalized(vcpu))
  

•   if (!kvm_arm_vcpu_vec_finalized(vcpu))
            return -EPERM;
  
    if (copy_to_user(uptr, vcpu->arch.sve_state + region.koffset,
  

@@ -523,7 +523,7 @@ static int set_sve_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) if (ret) return ret;

•   if (!kvm_arm_vcpu_sve_finalized(vcpu))
  

•   if (!kvm_arm_vcpu_vec_finalized(vcpu))
            return -EPERM;
  
    if (copy_from_user(vcpu->arch.sve_state + region.koffset, uptr,
  

@@ -599,7 +599,7 @@ static unsigned long num_sve_regs(const struct kvm_vcpu *vcpu) return 0;

    /* Policed by KVM_GET_REG_LIST: */

•   WARN_ON(!kvm_arm_vcpu_sve_finalized(vcpu));
  

•   WARN_ON(!kvm_arm_vcpu_vec_finalized(vcpu));
  
    return slices * (SVE_NUM_PREGS + SVE_NUM_ZREGS + 1 /* FFR */)
            + 1; /* KVM_REG_ARM64_SVE_VLS */
  

@@ -617,7 +617,7 @@ static int copy_sve_reg_indices(const struct kvm_vcpu *vcpu, return 0;

    /* Policed by KVM_GET_REG_LIST: */

•   WARN_ON(!kvm_arm_vcpu_sve_finalized(vcpu));
  

•   WARN_ON(!kvm_arm_vcpu_vec_finalized(vcpu));
  
    /*
     * Enumerate this first, so that userspace can save/restore in
  

diff --git a/arch/arm64/kvm/hyp/nvhe/pkvm.c b/arch/arm64/kvm/hyp/nvhe/pkvm.c index 8911338961c5..b402dcb7691e 100644 --- a/arch/arm64/kvm/hyp/nvhe/pkvm.c +++ b/arch/arm64/kvm/hyp/nvhe/pkvm.c @@ -445,7 +445,7 @@ static int pkvm_vcpu_init_sve(struct pkvm_hyp_vcpu *hyp_vcpu, struct kvm_vcpu *h int ret = 0;

    if (!vcpu_has_feature(vcpu, KVM_ARM_VCPU_SVE)) {

•           vcpu_clear_flag(vcpu, VCPU_SVE_FINALIZED);
  

•           vcpu_clear_flag(vcpu, VCPU_VEC_FINALIZED);
            return 0;
    }
  
  

diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c index 959532422d3a..f7c63e145d54 100644 --- a/arch/arm64/kvm/reset.c +++ b/arch/arm64/kvm/reset.c @@ -92,7 +92,7 @@ static void kvm_vcpu_enable_sve(struct kvm_vcpu *vcpu)

• Finalize vcpu's maximum SVE vector length, allocating
• vcpu->arch.sve_state as necessary.

*/ -static int kvm_vcpu_finalize_sve(struct kvm_vcpu *vcpu) +static int kvm_vcpu_finalize_vec(struct kvm_vcpu *vcpu) { void *buf; unsigned int vl; @@ -122,21 +122,21 @@ static int kvm_vcpu_finalize_sve(struct kvm_vcpu *vcpu) }

    vcpu->arch.sve_state = buf;

•   vcpu_set_flag(vcpu, VCPU_SVE_FINALIZED);
  

•   vcpu_set_flag(vcpu, VCPU_VEC_FINALIZED);
    return 0;
  

}

int kvm_arm_vcpu_finalize(struct kvm_vcpu *vcpu, int feature) { switch (feature) {

•   case KVM_ARM_VCPU_SVE:
  

•           if (!vcpu_has_sve(vcpu))
  

•   case KVM_ARM_VCPU_VEC:
  

•           if (!vcpu_has_vec(vcpu))
                    return -EINVAL;
  
  

•           if (kvm_arm_vcpu_sve_finalized(vcpu))
  

•           if (kvm_arm_vcpu_vec_finalized(vcpu))
                    return -EPERM;
  
  

•           return kvm_vcpu_finalize_sve(vcpu);
  

•           return kvm_vcpu_finalize_vec(vcpu);
    }
  
    return -EINVAL;
  

@@ -144,7 +144,7 @@ int kvm_arm_vcpu_finalize(struct kvm_vcpu *vcpu, int feature)

bool kvm_arm_vcpu_is_finalized(struct kvm_vcpu *vcpu) {

•   if (vcpu_has_sve(vcpu) && !kvm_arm_vcpu_sve_finalized(vcpu))
  

•   if (vcpu_has_vec(vcpu) && !kvm_arm_vcpu_vec_finalized(vcpu))
            return false;
  
    return true;
  

@@ -163,7 +163,7 @@ void kvm_arm_vcpu_destroy(struct kvm_vcpu *vcpu) kfree(vcpu->arch.ccsidr); }

-static void kvm_vcpu_reset_sve(struct kvm_vcpu *vcpu) +static void kvm_vcpu_reset_vec(struct kvm_vcpu *vcpu) { if (vcpu_has_sve(vcpu)) memset(vcpu->arch.sve_state, 0, vcpu_sve_state_size(vcpu)); @@ -203,11 +203,11 @@ void kvm_reset_vcpu(struct kvm_vcpu *vcpu) if (loaded) kvm_arch_vcpu_put(vcpu);

•   if (!kvm_arm_vcpu_sve_finalized(vcpu)) {
  

•   if (!kvm_arm_vcpu_vec_finalized(vcpu)) {
            if (vcpu_has_feature(vcpu, KVM_ARM_VCPU_SVE))
                    kvm_vcpu_enable_sve(vcpu);
    } else {
  

•           kvm_vcpu_reset_sve(vcpu);
  

•           kvm_vcpu_reset_vec(vcpu);
    }
  
    if (vcpu_el1_is_32bit(vcpu))
  
  

-- 2.47.3