[PATCH v13 12/32] KVM: arm64: Define internal features for SME
From: Mark Brown <broonie@kernel.org>
Date: 2026-07-19 23:10:49
Also in:
kvm, kvmarm, linux-doc, linux-kselftest, lkml
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds
In order to simplify interdependencies in the rest of the series define the feature detection for SME and its subfeatures. Due to the need for vector length configuration we define a flag for SME like for SVE. We also have two subfeatures which add architectural state, FA64 and SME2, which are configured via the normal ID register scheme. Also provide helpers which check if the vCPU is in streaming mode or has ZA enabled. Reviewed-by: Fuad Tabba <tabba@google.com> Signed-off-by: Mark Brown <broonie@kernel.org> --- arch/arm64/include/asm/kvm_host.h | 35 ++++++++++++++++++++++++++++++++++- arch/arm64/kvm/sys_regs.c | 2 +- 2 files changed, 35 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 8b746b1a1e53..8e185e43fbff 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h@@ -367,6 +367,8 @@ struct kvm_arch { #define KVM_ARCH_FLAG_WRITABLE_IMP_ID_REGS 10 /* Unhandled SEAs are taken to userspace */ #define KVM_ARCH_FLAG_EXIT_SEA 11 + /* SME exposed to guest */ +#define KVM_ARCH_FLAG_GUEST_HAS_SME 12 unsigned long flags; /* VM-wide vCPU feature set */
@@ -1133,7 +1135,16 @@ struct kvm_vcpu_arch { #define vcpu_has_sve(vcpu) kvm_has_sve((vcpu)->kvm) #endif -#define vcpu_has_vec(vcpu) vcpu_has_sve(vcpu) +#define kvm_has_sme(kvm) (system_supports_sme() && \ + test_bit(KVM_ARCH_FLAG_GUEST_HAS_SME, &(kvm)->arch.flags)) + +#ifdef __KVM_NVHE_HYPERVISOR__ +#define vcpu_has_sme(vcpu) kvm_has_sme(kern_hyp_va((vcpu)->kvm)) +#else +#define vcpu_has_sme(vcpu) kvm_has_sme((vcpu)->kvm) +#endif + +#define vcpu_has_vec(vcpu) (vcpu_has_sve(vcpu) || vcpu_has_sme(vcpu)) #ifdef CONFIG_ARM64_PTR_AUTH #define vcpu_has_ptrauth(vcpu) \
@@ -1650,6 +1661,28 @@ void kvm_set_vm_id_reg(struct kvm *kvm, u32 reg, u64 val); #define kvm_has_sctlr2(k) \ (kvm_has_feat((k), ID_AA64MMFR3_EL1, SCTLRX, IMP)) +#define kvm_has_fa64(k) \ + (system_supports_fa64() && \ + kvm_has_feat((k), ID_AA64SMFR0_EL1, FA64, IMP)) + +#define kvm_has_sme2(k) \ + (system_supports_sme2() && \ + kvm_has_feat((k), ID_AA64PFR1_EL1, SME, SME2)) + +#ifdef __KVM_NVHE_HYPERVISOR__ +#define vcpu_has_sme2(vcpu) kvm_has_sme2(kern_hyp_va((vcpu)->kvm)) +#define vcpu_has_fa64(vcpu) kvm_has_fa64(kern_hyp_va((vcpu)->kvm)) +#else +#define vcpu_has_sme2(vcpu) kvm_has_sme2((vcpu)->kvm) +#define vcpu_has_fa64(vcpu) kvm_has_fa64((vcpu)->kvm) +#endif + +#define vcpu_in_streaming_mode(vcpu) \ + (__vcpu_sys_reg(vcpu, SVCR) & SVCR_SM_MASK) + +#define vcpu_za_enabled(vcpu) \ + (__vcpu_sys_reg(vcpu, SVCR) & SVCR_ZA_MASK) + static inline bool kvm_arch_has_irq_bypass(void) { return true;
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index b352cd323e30..ba8a3ed8f5ff 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c@@ -2028,7 +2028,7 @@ static unsigned int sve_visibility(const struct kvm_vcpu *vcpu, static unsigned int sme_visibility(const struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd) { - if (kvm_has_feat(vcpu->kvm, ID_AA64PFR1_EL1, SME, IMP)) + if (vcpu_has_sme(vcpu)) return 0; return REG_HIDDEN;
--
2.47.3