5 files changed, 67 insertions, 1 deletions

diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h
index aa280f356b96..8eb63d329497 100644
--- a/arch/arm64/include/asm/virt.h
+++ b/arch/arm64/include/asm/virt.h
@@ -40,8 +40,13 @@
  */
 #define HVC_FINALISE_EL2	3
 
+/*
+ * HVC_GET_ICH_VTR_EL2 - Retrieve the ICH_VTR_EL2 value
+ */
+#define HVC_GET_ICH_VTR_EL2	4
+
 /* Max number of HYP stub hypercalls */
-#define HVC_STUB_HCALL_NR 4
+#define HVC_STUB_HCALL_NR 5
 
 /* Error returned when an invalid stub number is passed into x0 */
 #define HVC_STUB_ERR	0xbadca11
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 5ed401ff79e3..5de51cb1b8fe 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -2303,6 +2303,49 @@ static bool has_gic_prio_relaxed_sync(const struct arm64_cpu_capabilities *entry
 }
 #endif
 
+static bool can_trap_icv_dir_el1(const struct arm64_cpu_capabilities *entry,
+				 int scope)
+{
+	static const struct midr_range has_vgic_v3[] = {
+		MIDR_ALL_VERSIONS(MIDR_APPLE_M1_ICESTORM),
+		MIDR_ALL_VERSIONS(MIDR_APPLE_M1_FIRESTORM),
+		MIDR_ALL_VERSIONS(MIDR_APPLE_M1_ICESTORM_PRO),
+		MIDR_ALL_VERSIONS(MIDR_APPLE_M1_FIRESTORM_PRO),
+		MIDR_ALL_VERSIONS(MIDR_APPLE_M1_ICESTORM_MAX),
+		MIDR_ALL_VERSIONS(MIDR_APPLE_M1_FIRESTORM_MAX),
+		MIDR_ALL_VERSIONS(MIDR_APPLE_M2_BLIZZARD),
+		MIDR_ALL_VERSIONS(MIDR_APPLE_M2_AVALANCHE),
+		MIDR_ALL_VERSIONS(MIDR_APPLE_M2_BLIZZARD_PRO),
+		MIDR_ALL_VERSIONS(MIDR_APPLE_M2_AVALANCHE_PRO),
+		MIDR_ALL_VERSIONS(MIDR_APPLE_M2_BLIZZARD_MAX),
+		MIDR_ALL_VERSIONS(MIDR_APPLE_M2_AVALANCHE_MAX),
+		{},
+	};
+	struct arm_smccc_res res = {};
+
+	BUILD_BUG_ON(ARM64_HAS_ICH_HCR_EL2_TDIR <= ARM64_HAS_GICV3_CPUIF);
+	BUILD_BUG_ON(ARM64_HAS_ICH_HCR_EL2_TDIR <= ARM64_HAS_GICV5_LEGACY);
+	if (!cpus_have_cap(ARM64_HAS_GICV3_CPUIF) &&
+	    !is_midr_in_range_list(has_vgic_v3))
+		return false;
+
+	if (!is_hyp_mode_available())
+		return false;
+
+	if (cpus_have_cap(ARM64_HAS_GICV5_LEGACY))
+		return true;
+
+	if (is_kernel_in_hyp_mode())
+		res.a1 = read_sysreg_s(SYS_ICH_VTR_EL2);
+	else
+		arm_smccc_1_1_hvc(HVC_GET_ICH_VTR_EL2, &res);
+
+	if (res.a0 == HVC_STUB_ERR)
+		return false;
+
+	return res.a1 & ICH_VTR_EL2_TDS;
+}
+
 #ifdef CONFIG_ARM64_BTI
 static void bti_enable(const struct arm64_cpu_capabilities *__unused)
 {
@@ -2814,6 +2857,15 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
 		.matches = has_gic_prio_relaxed_sync,
 	},
 #endif
+	{
+		/*
+		 * Depends on having GICv3
+		 */
+		.desc = "ICV_DIR_EL1 trapping",
+		.capability = ARM64_HAS_ICH_HCR_EL2_TDIR,
+		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
+		.matches = can_trap_icv_dir_el1,
+	},
 #ifdef CONFIG_ARM64_E0PD
 	{
 		.desc = "E0PD",
diff --git a/arch/arm64/kernel/hyp-stub.S b/arch/arm64/kernel/hyp-stub.S
index 36e2d26b54f5..085bc9972f6b 100644
--- a/arch/arm64/kernel/hyp-stub.S
+++ b/arch/arm64/kernel/hyp-stub.S
@@ -54,6 +54,11 @@ SYM_CODE_START_LOCAL(elx_sync)
 1:	cmp	x0, #HVC_FINALISE_EL2
 	b.eq	__finalise_el2
 
+	cmp	x0, #HVC_GET_ICH_VTR_EL2
+	b.ne	2f
+	mrs_s	x1, SYS_ICH_VTR_EL2
+	b	9f
+
 2:	cmp	x0, #HVC_SOFT_RESTART
 	b.ne	3f
 	mov	x0, x2
diff --git a/arch/arm64/kvm/vgic/vgic-v3.c b/arch/arm64/kvm/vgic/vgic-v3.c
index 8c1494508682..1b6c3071ec80 100644
--- a/arch/arm64/kvm/vgic/vgic-v3.c
+++ b/arch/arm64/kvm/vgic/vgic-v3.c
@@ -648,6 +648,9 @@ void noinstr kvm_compute_ich_hcr_trap_bits(struct alt_instr *alt,
 		dir_trap = true;
 	}
 
+	if (!cpus_have_cap(ARM64_HAS_ICH_HCR_EL2_TDIR))
+		common_trap = true;
+
 	if (group0_trap)
 		hcr |= ICH_HCR_EL2_TALL0;
 	if (group1_trap)
diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps
index 1b32c1232d28..116d1a7b688c 100644
--- a/arch/arm64/tools/cpucaps
+++ b/arch/arm64/tools/cpucaps
@@ -40,6 +40,7 @@ HAS_GICV5_CPUIF
 HAS_GICV5_LEGACY
 HAS_GIC_PRIO_MASKING
 HAS_GIC_PRIO_RELAXED_SYNC
+HAS_ICH_HCR_EL2_TDIR
 HAS_HCR_NV1
 HAS_HCX
 HAS_LDAPR