KVM: arm64: Expose TSO capability to guests and context switch

Signed-off-by: Asahi Lina <lina@asahilina.net>

Author: hoshinolina

arch/arm64/include/asm/kvm_emulate.h

@@ -103,6 +103,11 @@ static inline void vcpu_reset_hcr(struct kvm_vcpu *vcpu)
 {
 	if (!vcpu_has_run_once(vcpu))
 		vcpu->arch.hcr_el2 = HCR_GUEST_FLAGS;
+	if (IS_ENABLED(CONFIG_ARM64_ACTLR_STATE) && (
+			alternative_has_cap_unlikely(ARM64_HAS_ACTLR_VIRT) ||
+			alternative_has_cap_unlikely(ARM64_HAS_ACTLR_VIRT_APPLE)
+		))
+		vcpu->arch.hcr_el2 &= ~HCR_TACR;
 
 	/*
 	 * For non-FWB CPUs, we trap VM ops (HCR_EL2.TVM) until M+C

arch/arm64/kernel/cpufeature_impdef.c

@@ -62,6 +62,20 @@ static bool has_tso_fixed(const struct arm64_cpu_capabilities *entry, int scope)
 }
 #endif
 
+static bool has_apple_actlr_virt_impdef(const struct arm64_cpu_capabilities *entry, int scope)
+{
+	u64 midr = read_cpuid_id() & MIDR_CPU_MODEL_MASK;
+
+	return midr >= MIDR_APPLE_M1_ICESTORM && midr <= MIDR_APPLE_M1_FIRESTORM_MAX;
+}
+
+static bool has_apple_actlr_virt(const struct arm64_cpu_capabilities *entry, int scope)
+{
+	u64 midr = read_cpuid_id() & MIDR_CPU_MODEL_MASK;
+
+	return midr >= MIDR_APPLE_M2_BLIZZARD && midr <= MIDR_CPU_MODEL(ARM_CPU_IMP_APPLE, 0xfff);
+}
+
 static const struct arm64_cpu_capabilities arm64_impdef_features[] = {
 #ifdef CONFIG_ARM64_MEMORY_MODEL_CONTROL
 	{
@@ -82,6 +96,18 @@ static const struct arm64_cpu_capabilities arm64_impdef_features[] = {
 		.matches = has_tso_fixed,
 	},
 #endif
+	{
+		.desc = "ACTLR virtualization (IMPDEF, Apple)",
+		.capability = ARM64_HAS_ACTLR_VIRT_APPLE,
+		.type = ARM64_CPUCAP_EARLY_LOCAL_CPU_FEATURE,
+		.matches = has_apple_actlr_virt_impdef,
+	},
+	{
+		.desc = "ACTLR virtualization (architectural?)",
+		.capability = ARM64_HAS_ACTLR_VIRT,
+		.type = ARM64_CPUCAP_EARLY_LOCAL_CPU_FEATURE,
+		.matches = has_apple_actlr_virt,
+	},
 	{},
 };
 

arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h

@@ -16,6 +16,9 @@
 #include <asm/kvm_hyp.h>
 #include <asm/kvm_mmu.h>
 
+#define SYS_IMP_APL_ACTLR_EL12		sys_reg(3, 6, 15, 14, 6)
+#define SYS_ACTLR_EL12			sys_reg(3, 5, 1, 0, 1)
+
 static inline bool ctxt_has_s1poe(struct kvm_cpu_context *ctxt);
 
 static inline struct kvm_vcpu *ctxt_to_vcpu(struct kvm_cpu_context *ctxt)
@@ -172,6 +175,13 @@ static inline void __sysreg_save_el1_state(struct kvm_cpu_context *ctxt)
 
 	if (ctxt_has_sctlr2(ctxt))
 		ctxt_sys_reg(ctxt, SCTLR2_EL1) = read_sysreg_el1(SYS_SCTLR2);
+
+	if (IS_ENABLED(CONFIG_ARM64_ACTLR_STATE)) {
+		if (alternative_has_cap_unlikely(ARM64_HAS_ACTLR_VIRT))
+			ctxt_sys_reg(ctxt, ACTLR_EL1)	= read_sysreg_s(SYS_ACTLR_EL12);
+		else if (alternative_has_cap_unlikely(ARM64_HAS_ACTLR_VIRT_APPLE))
+			ctxt_sys_reg(ctxt, ACTLR_EL1)	= read_sysreg_s(SYS_IMP_APL_ACTLR_EL12);
+	}
 }
 
 static inline void __sysreg_save_el2_return_state(struct kvm_cpu_context *ctxt)
@@ -256,6 +266,13 @@ static inline void __sysreg_restore_el1_state(struct kvm_cpu_context *ctxt,
 	write_sysreg(ctxt_sys_reg(ctxt, PAR_EL1),	par_el1);
 	write_sysreg(ctxt_sys_reg(ctxt, TPIDR_EL1),	tpidr_el1);
 
+	if (IS_ENABLED(CONFIG_ARM64_ACTLR_STATE)) {
+		if (alternative_has_cap_unlikely(ARM64_HAS_ACTLR_VIRT))
+			write_sysreg_s(ctxt_sys_reg(ctxt, ACTLR_EL1), SYS_ACTLR_EL12);
+		else if (alternative_has_cap_unlikely(ARM64_HAS_ACTLR_VIRT_APPLE))
+			write_sysreg_s(ctxt_sys_reg(ctxt, ACTLR_EL1), SYS_IMP_APL_ACTLR_EL12);
+	}
+
 	if (ctxt_has_mte(ctxt)) {
 		write_sysreg_el1(ctxt_sys_reg(ctxt, TFSR_EL1), SYS_TFSR);
 		write_sysreg_s(ctxt_sys_reg(ctxt, TFSRE0_EL1), SYS_TFSRE0_EL1);

arch/arm64/tools/cpucaps

@@ -8,6 +8,8 @@ BTI
 # Unreliable: use system_supports_32bit_el0() instead.
 HAS_32BIT_EL0_DO_NOT_USE
 HAS_32BIT_EL1
+HAS_ACTLR_VIRT
+HAS_ACTLR_VIRT_APPLE
 HAS_ADDRESS_AUTH
 HAS_ADDRESS_AUTH_ARCH_QARMA3
 HAS_ADDRESS_AUTH_ARCH_QARMA5