[RFC PATCH v5 22/38] KVM: arm64: Add SPE VCPU device attribute to initialize SPE

[Alexandru Elisei]

From: Sudeep Holla <sudeep.holla at arm.com>

Add KVM_ARM_VCPU_SPE_CTRL(KVM_ARM_VCPU_SPE_INIT) VCPU ioctl to initialize
SPE. Initialization can only be done once for a VCPU. If the feature bit is
set, then SPE must be initialized before the VCPU can be run.

[ Alexandru E: Split from "KVM: arm64: Add a new VCPU device control group
	       for SPE" ]

Signed-off-by: Sudeep Holla <sudeep.holla at arm.com>
Signed-off-by: Alexandru Elisei <alexandru.elisei at arm.com>
---
 Documentation/virt/kvm/devices/vcpu.rst | 16 ++++++++++++++++
 arch/arm64/include/asm/kvm_spe.h        |  6 ++++++
 arch/arm64/include/uapi/asm/kvm.h       |  1 +
 arch/arm64/kvm/arm.c                    |  4 ++++
 arch/arm64/kvm/spe.c                    | 24 ++++++++++++++++++++++++
 5 files changed, 51 insertions(+)

diff --git a/Documentation/virt/kvm/devices/vcpu.rst b/Documentation/virt/kvm/devices/vcpu.rst
index a27b149c3b8b..0ed852315664 100644
--- a/Documentation/virt/kvm/devices/vcpu.rst
+++ b/Documentation/virt/kvm/devices/vcpu.rst
@@ -255,3 +255,19 @@ Returns:
 Specifies the Profiling Buffer management interrupt number. The interrupt number
 must be a PPI and the interrupt number must be the same for each VCPU. SPE
 emulation requires an in-kernel vGIC implementation.
+
+5.2 ATTRIBUTE: KVM_ARM_VCPU_SPE_INIT
+-----------------------------------
+
+:Parameters: no additional parameter in kvm_device_attr.addr
+
+Returns:
+
+	 =======  ============================================
+	 -EBUSY   SPE already initialized for this VCPU
+	 -ENXIO   SPE not supported or not properly configured
+	 =======  ============================================
+
+Request initialization of the Statistical Profiling Extension for this VCPU.
+Must be done after initializaing the in-kernel irqchip and after setting the
+Profiling Buffer management interrupt number for the VCPU.
diff --git a/arch/arm64/include/asm/kvm_spe.h b/arch/arm64/include/asm/kvm_spe.h
index a5484953d06f..14df2c830fda 100644
--- a/arch/arm64/include/asm/kvm_spe.h
+++ b/arch/arm64/include/asm/kvm_spe.h
@@ -22,6 +22,7 @@ struct kvm_vcpu_spe {
 };
 
 int kvm_spe_vcpu_enable_spe(struct kvm_vcpu *vcpu);
+int kvm_spe_vcpu_first_run_init(struct kvm_vcpu *vcpu);
 
 int kvm_spe_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr);
 int kvm_spe_get_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr);
@@ -37,6 +38,11 @@ static inline int kvm_spe_vcpu_enable_spe(struct kvm_vcpu *vcpu)
 	return 0;
 }
 
+static inline int kvm_spe_vcpu_first_run_init(struct kvm_vcpu *vcpu)
+{
+	return 0;
+}
+
 static inline int kvm_spe_set_attr(struct kvm_vcpu *vcpu,
 				   struct kvm_device_attr *attr)
 {
diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
index c55d94a1a8f5..d4c0b53a5fb2 100644
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/arch/arm64/include/uapi/asm/kvm.h
@@ -370,6 +370,7 @@ struct kvm_arm_copy_mte_tags {
 #define   KVM_ARM_VCPU_PVTIME_IPA	0
 #define KVM_ARM_VCPU_SPE_CTRL		3
 #define   KVM_ARM_VCPU_SPE_IRQ		0
+#define   KVM_ARM_VCPU_SPE_INIT		1
 
 /* KVM_IRQ_LINE irq field index values */
 #define KVM_ARM_IRQ_VCPU2_SHIFT		28
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 8a7c01d1df58..5270f3b9886c 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -652,6 +652,10 @@ static int kvm_vcpu_first_run_init(struct kvm_vcpu *vcpu)
 		return ret;
 
 	ret = kvm_arm_pmu_v3_enable(vcpu);
+	if (ret)
+		return ret;
+
+	ret = kvm_spe_vcpu_first_run_init(vcpu);
 
 	/*
 	 * Initialize traps for protected VMs.
diff --git a/arch/arm64/kvm/spe.c b/arch/arm64/kvm/spe.c
index 7520d7925460..a3d5bcd1a96b 100644
--- a/arch/arm64/kvm/spe.c
+++ b/arch/arm64/kvm/spe.c
@@ -45,6 +45,17 @@ int kvm_spe_vcpu_enable_spe(struct kvm_vcpu *vcpu)
 	return 0;
 }
 
+int kvm_spe_vcpu_first_run_init(struct kvm_vcpu *vcpu)
+{
+	if (!kvm_vcpu_has_spe(vcpu))
+		return 0;
+
+	if (!vcpu->arch.spe.initialized)
+		return -EINVAL;
+
+	return 0;
+}
+
 static bool kvm_vcpu_supports_spe(struct kvm_vcpu *vcpu)
 {
 	if (!kvm_supports_spe())
@@ -104,6 +115,18 @@ int kvm_spe_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
 		vcpu->arch.spe.irq_num = irq;
 		return 0;
 	}
+	case KVM_ARM_VCPU_SPE_INIT:
+		if (!vcpu->arch.spe.irq_num)
+			return -ENXIO;
+
+		if (!vgic_initialized(vcpu->kvm))
+			return -ENXIO;
+
+		if (kvm_vgic_set_owner(vcpu, vcpu->arch.spe.irq_num, &vcpu->arch.spe))
+			return -ENXIO;
+
+		vcpu->arch.spe.initialized = true;
+		return 0;
 	}
 
 	return -ENXIO;
@@ -140,6 +163,7 @@ int kvm_spe_has_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
 
 	switch(attr->attr) {
 	case KVM_ARM_VCPU_SPE_IRQ:
+	case KVM_ARM_VCPU_SPE_INIT:
 		return 0;
 	}
 
-- 
2.33.1