SME adds a new thread ID register, TPIDR2_EL0. This is used in userspace for delayed saving of the ZA state but in terms of the architecture is not really connected to SME other than being part of FEAT_SME. It has an independent fine grained trap and the runtime connection with the rest of SME is purely software defined.
Expose the register as a system register if the guest supports SME, context switching it along with the other EL0 TPIDRs.
Signed-off-by: Mark Brown broonie@kernel.org --- arch/arm64/include/asm/kvm_host.h | 1 + arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h | 15 +++++++++++++++ arch/arm64/kvm/sys_regs.c | 9 ++++++--- 3 files changed, 22 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index f987698f88acf7b01e08e44b46a0982e36cced95..c770ed6138164fcd3e11b8517ef4120b4f4486b9 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -429,6 +429,7 @@ enum vcpu_sysreg { CSSELR_EL1, /* Cache Size Selection Register */ TPIDR_EL0, /* Thread ID, User R/W */ TPIDRRO_EL0, /* Thread ID, User R/O */ + TPIDR2_EL0, /* Thread ID, Register 2 */ TPIDR_EL1, /* Thread ID, Privileged */ CNTKCTL_EL1, /* Timer Control Register (EL1) */ PAR_EL1, /* Physical Address Register */ diff --git a/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h b/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h index 7a4ad8a4c3727e4628b375cbefc5e0d3533687de..8141e4785161d0f610f1aa161d8448ca2f50312c 100644 --- a/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h +++ b/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h @@ -81,6 +81,17 @@ static inline u64 *ctxt_mdscr_el1(struct kvm_cpu_context *ctxt) return &ctxt_sys_reg(ctxt, MDSCR_EL1); }
+static inline bool ctxt_has_sme(struct kvm_cpu_context *ctxt) +{ + struct kvm_vcpu *vcpu; + + if (!system_supports_sme()) + return false; + + vcpu = ctxt_to_vcpu(ctxt); + return kvm_has_sme(kern_hyp_va(vcpu->kvm)); +} + static inline void __sysreg_save_common_state(struct kvm_cpu_context *ctxt) { *ctxt_mdscr_el1(ctxt) = read_sysreg(mdscr_el1); @@ -94,6 +105,8 @@ static inline void __sysreg_save_user_state(struct kvm_cpu_context *ctxt) { ctxt_sys_reg(ctxt, TPIDR_EL0) = read_sysreg(tpidr_el0); ctxt_sys_reg(ctxt, TPIDRRO_EL0) = read_sysreg(tpidrro_el0); + if (ctxt_has_sme(ctxt)) + ctxt_sys_reg(ctxt, TPIDR2_EL0) = read_sysreg_s(SYS_TPIDR2_EL0); }
static inline void __sysreg_save_el1_state(struct kvm_cpu_context *ctxt) @@ -163,6 +176,8 @@ static inline void __sysreg_restore_user_state(struct kvm_cpu_context *ctxt) { write_sysreg(ctxt_sys_reg(ctxt, TPIDR_EL0), tpidr_el0); write_sysreg(ctxt_sys_reg(ctxt, TPIDRRO_EL0), tpidrro_el0); + if (ctxt_has_sme(ctxt)) + write_sysreg_s(ctxt_sys_reg(ctxt, TPIDR2_EL0), SYS_TPIDR2_EL0); }
static inline void __sysreg_restore_el1_state(struct kvm_cpu_context *ctxt, diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 597d6a33826d001268d53174581ef8e61e7dd946..eece67141480b8d4bbd2bac0f02f9208c7f86f8b 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -2901,7 +2901,8 @@ static const struct sys_reg_desc sys_reg_descs[] = { .visibility = s1poe_visibility }, { SYS_DESC(SYS_TPIDR_EL0), NULL, reset_unknown, TPIDR_EL0 }, { SYS_DESC(SYS_TPIDRRO_EL0), NULL, reset_unknown, TPIDRRO_EL0 }, - { SYS_DESC(SYS_TPIDR2_EL0), undef_access }, + { SYS_DESC(SYS_TPIDR2_EL0), NULL, reset_unknown, TPIDR2_EL0, + .visibility = sme_visibility},
{ SYS_DESC(SYS_SCXTNUM_EL0), undef_access },
@@ -5033,8 +5034,7 @@ void kvm_calculate_traps(struct kvm_vcpu *vcpu) HFGxTR_EL2_nMAIR2_EL1 | HFGxTR_EL2_nS2POR_EL1 | HFGxTR_EL2_nACCDATA_EL1 | - HFGxTR_EL2_nSMPRI_EL1_MASK | - HFGxTR_EL2_nTPIDR2_EL0_MASK); + HFGxTR_EL2_nSMPRI_EL1_MASK);
if (!kvm_has_feat(kvm, ID_AA64ISAR0_EL1, TLB, OS)) kvm->arch.fgu[HFGITR_GROUP] |= (HFGITR_EL2_TLBIRVAALE1OS| @@ -5089,6 +5089,9 @@ void kvm_calculate_traps(struct kvm_vcpu *vcpu) HFGITR_EL2_nBRBIALL); }
+ if (!kvm_has_feat(kvm, ID_AA64PFR1_EL1, SME, IMP)) + kvm->arch.fgu[HFGxTR_GROUP] |= HFGxTR_EL2_nTPIDR2_EL0; + set_bit(KVM_ARCH_FLAG_FGU_INITIALIZED, &kvm->arch.flags); out: mutex_unlock(&kvm->arch.config_lock);