[PATCH v5 04/10] KVM: arm64: Add vendor hypervisor firmware register

[Raghavendra Rao Ananta <rananta@google.com>]

Introduce the firmware register to hold the vendor specific
hypervisor service calls (owner value 6) as a bitmap. The
bitmap represents the features that'll be enabled for the
guest, as configured by the user-space. Currently, this
includes support for KVM-vendor features, and Precision Time
Protocol (PTP), represented by bit-0 and bit-1 respectively.

Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
---
 arch/arm64/include/asm/kvm_host.h |  2 ++
 arch/arm64/include/uapi/asm/kvm.h |  4 ++++
 arch/arm64/kvm/hypercalls.c       | 21 +++++++++++++++++----
 include/kvm/arm_hypercalls.h      |  4 ++++
 4 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 20165242ebd9..b79161bad69a 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -106,10 +106,12 @@ struct kvm_arch_memory_slot {
  *
  * @std_bmap: Bitmap of standard secure service calls
  * @std_hyp_bmap: Bitmap of standard hypervisor service calls
+ * @vendor_hyp_bmap: Bitmap of vendor specific hypervisor service calls
  */
 struct kvm_smccc_features {
 	u64 std_bmap;
 	u64 std_hyp_bmap;
+	u64 vendor_hyp_bmap;
 };
 
 struct kvm_arch {
diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
index 67353bf4e69d..9a5ac0ed4113 100644
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/arch/arm64/include/uapi/asm/kvm.h
@@ -344,6 +344,10 @@ struct kvm_arm_copy_mte_tags {
 #define KVM_REG_ARM_STD_HYP_BMAP		KVM_REG_ARM_FW_FEAT_BMAP_REG(1)
 #define KVM_REG_ARM_STD_HYP_BIT_PV_TIME		BIT(0)
 
+#define KVM_REG_ARM_VENDOR_HYP_BMAP		KVM_REG_ARM_FW_FEAT_BMAP_REG(2)
+#define KVM_REG_ARM_VENDOR_HYP_BIT_FUNC_FEAT	BIT(0)
+#define KVM_REG_ARM_VENDOR_HYP_BIT_PTP		BIT(1)
+
 /* Device Control API: ARM VGIC */
 #define KVM_DEV_ARM_VGIC_GRP_ADDR	0
 #define KVM_DEV_ARM_VGIC_GRP_DIST_REGS	1
diff --git a/arch/arm64/kvm/hypercalls.c b/arch/arm64/kvm/hypercalls.c
index 64ae6c7e7145..80836c341fd3 100644
--- a/arch/arm64/kvm/hypercalls.c
+++ b/arch/arm64/kvm/hypercalls.c
@@ -66,8 +66,6 @@ static const u32 hvc_func_default_allowed_list[] = {
 	ARM_SMCCC_VERSION_FUNC_ID,
 	ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
 	ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID,
-	ARM_SMCCC_VENDOR_HYP_KVM_FEATURES_FUNC_ID,
-	ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID,
 };
 
 static bool kvm_hvc_call_default_allowed(struct kvm_vcpu *vcpu, u32 func_id)
@@ -102,6 +100,12 @@ static bool kvm_hvc_call_allowed(struct kvm_vcpu *vcpu, u32 func_id)
 	case ARM_SMCCC_HV_PV_TIME_ST:
 		return kvm_arm_fw_reg_feat_enabled(smccc_feat->std_hyp_bmap,
 					KVM_REG_ARM_STD_HYP_BIT_PV_TIME);
+	case ARM_SMCCC_VENDOR_HYP_KVM_FEATURES_FUNC_ID:
+		return kvm_arm_fw_reg_feat_enabled(smccc_feat->vendor_hyp_bmap,
+					KVM_REG_ARM_VENDOR_HYP_BIT_FUNC_FEAT);
+	case ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID:
+		return kvm_arm_fw_reg_feat_enabled(smccc_feat->vendor_hyp_bmap,
+					KVM_REG_ARM_VENDOR_HYP_BIT_PTP);
 	default:
 		return kvm_hvc_call_default_allowed(vcpu, func_id);
 	}
@@ -194,8 +198,7 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu)
 		val[3] = ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_3;
 		break;
 	case ARM_SMCCC_VENDOR_HYP_KVM_FEATURES_FUNC_ID:
-		val[0] = BIT(ARM_SMCCC_KVM_FUNC_FEATURES);
-		val[0] |= BIT(ARM_SMCCC_KVM_FUNC_PTP);
+		val[0] = smccc_feat->vendor_hyp_bmap;
 		break;
 	case ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID:
 		kvm_ptp_get_time(vcpu, val);
@@ -222,6 +225,7 @@ static const u64 kvm_arm_fw_reg_ids[] = {
 	KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3,
 	KVM_REG_ARM_STD_BMAP,
 	KVM_REG_ARM_STD_HYP_BMAP,
+	KVM_REG_ARM_VENDOR_HYP_BMAP,
 };
 
 void kvm_arm_init_hypercalls(struct kvm *kvm)
@@ -230,6 +234,7 @@ void kvm_arm_init_hypercalls(struct kvm *kvm)
 
 	smccc_feat->std_bmap = KVM_ARM_SMCCC_STD_FEATURES;
 	smccc_feat->std_hyp_bmap = KVM_ARM_SMCCC_STD_HYP_FEATURES;
+	smccc_feat->vendor_hyp_bmap = KVM_ARM_SMCCC_VENDOR_HYP_FEATURES;
 }
 
 int kvm_arm_get_fw_num_regs(struct kvm_vcpu *vcpu)
@@ -322,6 +327,9 @@ int kvm_arm_get_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 	case KVM_REG_ARM_STD_HYP_BMAP:
 		val = READ_ONCE(smccc_feat->std_hyp_bmap);
 		break;
+	case KVM_REG_ARM_VENDOR_HYP_BMAP:
+		val = READ_ONCE(smccc_feat->vendor_hyp_bmap);
+		break;
 	default:
 		return -ENOENT;
 	}
@@ -348,6 +356,10 @@ static int kvm_arm_set_fw_reg_bmap(struct kvm_vcpu *vcpu, u64 reg_id, u64 val)
 		fw_reg_bmap = &smccc_feat->std_hyp_bmap;
 		fw_reg_features = KVM_ARM_SMCCC_STD_HYP_FEATURES;
 		break;
+	case KVM_REG_ARM_VENDOR_HYP_BMAP:
+		fw_reg_bmap = &smccc_feat->vendor_hyp_bmap;
+		fw_reg_features = KVM_ARM_SMCCC_VENDOR_HYP_FEATURES;
+		break;
 	default:
 		return -ENOENT;
 	}
@@ -453,6 +465,7 @@ int kvm_arm_set_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 		return 0;
 	case KVM_REG_ARM_STD_BMAP:
 	case KVM_REG_ARM_STD_HYP_BMAP:
+	case KVM_REG_ARM_VENDOR_HYP_BMAP:
 		return kvm_arm_set_fw_reg_bmap(vcpu, reg->id, val);
 	default:
 		return -ENOENT;
diff --git a/include/kvm/arm_hypercalls.h b/include/kvm/arm_hypercalls.h
index b0915d8c5b81..eaf4f6b318a8 100644
--- a/include/kvm/arm_hypercalls.h
+++ b/include/kvm/arm_hypercalls.h
@@ -9,6 +9,7 @@
 /* Last valid bits of the bitmapped firmware registers */
 #define KVM_REG_ARM_STD_BMAP_BIT_MAX		0
 #define KVM_REG_ARM_STD_HYP_BMAP_BIT_MAX	0
+#define KVM_REG_ARM_VENDOR_HYP_BMAP_BIT_MAX	1
 
 #define KVM_ARM_SMCCC_STD_FEATURES \
 	GENMASK_ULL(KVM_REG_ARM_STD_BMAP_BIT_MAX, 0)
@@ -16,6 +17,9 @@
 #define KVM_ARM_SMCCC_STD_HYP_FEATURES \
 	GENMASK_ULL(KVM_REG_ARM_STD_HYP_BMAP_BIT_MAX, 0)
 
+#define KVM_ARM_SMCCC_VENDOR_HYP_FEATURES \
+	GENMASK_ULL(KVM_REG_ARM_VENDOR_HYP_BMAP_BIT_MAX, 0)
+
 int kvm_hvc_call_handler(struct kvm_vcpu *vcpu);
 
 static inline u32 smccc_get_function(struct kvm_vcpu *vcpu)
-- 
2.35.1.1094.g7c7d902a7c-goog