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Date:   Mon,  2 May 2022 23:38:48 +0000
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Subject: [PATCH v7 4/9] KVM: arm64: Add vendor hypervisor firmware register
From:   Raghavendra Rao Ananta <rananta@google.com>
To:     Marc Zyngier <maz@kernel.org>, Andrew Jones <drjones@redhat.com>,
        James Morse <james.morse@arm.com>,
        Alexandru Elisei <alexandru.elisei@arm.com>,
        Suzuki K Poulose <suzuki.poulose@arm.com>
Cc:     Paolo Bonzini <pbonzini@redhat.com>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>, Peter Shier <pshier@google.com>,
        Ricardo Koller <ricarkol@google.com>,
        Oliver Upton <oupton@google.com>,
        Reiji Watanabe <reijiw@google.com>,
        Jing Zhang <jingzhangos@google.com>,
        Raghavendra Rao Anata <rananta@google.com>,
        linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu,
        linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
        Gavin Shan <gshan@redhat.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

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 along with
reading the UID, represented by bit-0, and Precision Time
Protocol (PTP), represented by bit-1.

Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
---
 arch/arm64/include/asm/kvm_host.h |  2 ++
 arch/arm64/include/uapi/asm/kvm.h |  4 ++++
 arch/arm64/kvm/hypercalls.c       | 23 ++++++++++++++++++-----
 include/kvm/arm_hypercalls.h      |  2 ++
 4 files changed, 26 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 281dfcfd0a4e..35a60d766fba 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 {
 	unsigned long std_bmap;
 	unsigned long std_hyp_bmap;
+	unsigned long 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 9eecc7ee8c14..e7d5ae222684 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		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	0
+#define KVM_REG_ARM_VENDOR_HYP_BIT_PTP		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 38440e0bd4b4..c4f2abd49e69 100644
--- a/arch/arm64/kvm/hypercalls.c
+++ b/arch/arm64/kvm/hypercalls.c
@@ -72,9 +72,6 @@ static bool kvm_hvc_call_default_allowed(u32 func_id)
 	 */
 	case ARM_SMCCC_VERSION_FUNC_ID:
 	case ARM_SMCCC_ARCH_FEATURES_FUNC_ID:
-	case ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID:
-	case ARM_SMCCC_VENDOR_HYP_KVM_FEATURES_FUNC_ID:
-	case ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID:
 		return true;
 	default:
 		return kvm_psci_func_id_is_valid(func_id);
@@ -97,6 +94,13 @@ 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:
+	case ARM_SMCCC_VENDOR_HYP_CALL_UID_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(func_id);
 	}
@@ -189,8 +193,7 @@ 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);
@@ -217,6 +220,7 @@ 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)
@@ -225,6 +229,7 @@ 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)
@@ -317,6 +322,9 @@ 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;
 	}
@@ -343,6 +351,10 @@ 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;
 	}
@@ -457,6 +469,7 @@ 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 00f9f1b1dc16..7d4d953680f7 100644
--- a/include/kvm/arm_hypercalls.h
+++ b/include/kvm/arm_hypercalls.h
@@ -9,9 +9,11 @@
 /* Last valid bit 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(KVM_REG_ARM_STD_BMAP_BIT_MAX, 0)
 #define KVM_ARM_SMCCC_STD_HYP_FEATURES		GENMASK(KVM_REG_ARM_STD_HYP_BMAP_BIT_MAX, 0)
+#define KVM_ARM_SMCCC_VENDOR_HYP_FEATURES	GENMASK(KVM_REG_ARM_VENDOR_HYP_BMAP_BIT_MAX, 0)
 
 int kvm_hvc_call_handler(struct kvm_vcpu *vcpu);
 
-- 
2.36.0.464.gb9c8b46e94-goog