KVM: arm64: Make PIR{,E0}_EL1 UNDEF if S1PIE is not advertised to the guest

As part of the ongoing effort to honor the guest configuration,
add the necessary checks to make PIR_EL1 and co UNDEF if not
advertised to the guest, and avoid context switching them.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Link: https://lore.kernel.org/r/20240214131827.2856277-23-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>

diff --git a/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h b/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h
index bb6b571ec627dede466c5fa1d05785a9c9f78764..4be6a7fa007082ac008c83422e9bb69b0f5da324 100644 (file)
--- a/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h
+++ b/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h
@@ -27,16 +27,34 @@ static inline void __sysreg_save_user_state(struct kvm_cpu_context *ctxt)
        ctxt_sys_reg(ctxt, TPIDRRO_EL0) = read_sysreg(tpidrro_el0);
 }
 
-static inline bool ctxt_has_mte(struct kvm_cpu_context *ctxt)
+static inline struct kvm_vcpu *ctxt_to_vcpu(struct kvm_cpu_context *ctxt)
 {
        struct kvm_vcpu *vcpu = ctxt->__hyp_running_vcpu;
 
        if (!vcpu)
                vcpu = container_of(ctxt, struct kvm_vcpu, arch.ctxt);
 
+       return vcpu;
+}
+
+static inline bool ctxt_has_mte(struct kvm_cpu_context *ctxt)
+{
+       struct kvm_vcpu *vcpu = ctxt_to_vcpu(ctxt);
+
        return kvm_has_mte(kern_hyp_va(vcpu->kvm));
 }
 
+static inline bool ctxt_has_s1pie(struct kvm_cpu_context *ctxt)
+{
+       struct kvm_vcpu *vcpu;
+
+       if (!cpus_have_final_cap(ARM64_HAS_S1PIE))
+               return false;
+
+       vcpu = ctxt_to_vcpu(ctxt);
+       return kvm_has_feat(kern_hyp_va(vcpu->kvm), ID_AA64MMFR3_EL1, S1PIE, IMP);
+}
+
 static inline void __sysreg_save_el1_state(struct kvm_cpu_context *ctxt)
 {
        ctxt_sys_reg(ctxt, SCTLR_EL1)   = read_sysreg_el1(SYS_SCTLR);
@@ -55,7 +73,7 @@ static inline void __sysreg_save_el1_state(struct kvm_cpu_context *ctxt)
        ctxt_sys_reg(ctxt, CONTEXTIDR_EL1) = read_sysreg_el1(SYS_CONTEXTIDR);
        ctxt_sys_reg(ctxt, AMAIR_EL1)   = read_sysreg_el1(SYS_AMAIR);
        ctxt_sys_reg(ctxt, CNTKCTL_EL1) = read_sysreg_el1(SYS_CNTKCTL);
-       if (cpus_have_final_cap(ARM64_HAS_S1PIE)) {
+       if (ctxt_has_s1pie(ctxt)) {
                ctxt_sys_reg(ctxt, PIR_EL1)     = read_sysreg_el1(SYS_PIR);
                ctxt_sys_reg(ctxt, PIRE0_EL1)   = read_sysreg_el1(SYS_PIRE0);
        }
@@ -131,7 +149,7 @@ static inline void __sysreg_restore_el1_state(struct kvm_cpu_context *ctxt)
        write_sysreg_el1(ctxt_sys_reg(ctxt, CONTEXTIDR_EL1), SYS_CONTEXTIDR);
        write_sysreg_el1(ctxt_sys_reg(ctxt, AMAIR_EL1), SYS_AMAIR);
        write_sysreg_el1(ctxt_sys_reg(ctxt, CNTKCTL_EL1), SYS_CNTKCTL);
-       if (cpus_have_final_cap(ARM64_HAS_S1PIE)) {
+       if (ctxt_has_s1pie(ctxt)) {
                write_sysreg_el1(ctxt_sys_reg(ctxt, PIR_EL1),   SYS_PIR);
                write_sysreg_el1(ctxt_sys_reg(ctxt, PIRE0_EL1), SYS_PIRE0);
        }

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index f07ee7c89822f233fb07c82618b7d0f3dead8635..da9db99c77e7c607c0c807c7a1cdeb6470bdc11b 100644 (file)
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -3994,6 +3994,10 @@ void kvm_init_sysreg(struct kvm_vcpu *vcpu)
                                                HFGITR_EL2_TLBIRVAAE1OS |
                                                HFGITR_EL2_TLBIRVAE1OS);
 
+       if (!kvm_has_feat(kvm, ID_AA64MMFR3_EL1, S1PIE, IMP))
+               kvm->arch.fgu[HFGxTR_GROUP] |= (HFGxTR_EL2_nPIRE0_EL1 |
+                                               HFGxTR_EL2_nPIR_EL1);
+
        set_bit(KVM_ARCH_FLAG_FGU_INITIALIZED, &kvm->arch.flags);
 out:
        mutex_unlock(&kvm->arch.config_lock);