[RFC PATCH v4 21/39] KVM: arm64: Add SPE VCPU device attribute to set the interrupt number
From: Alexandru Elisei <hidden>
Date: 2021-08-25 16:18:15
Also in:
kvmarm, lkml
Subsystem:
arm64 port (aarch64 architecture), documentation, kernel virtual machine (kvm), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Jonathan Corbet, Paolo Bonzini, Marc Zyngier, Oliver Upton, Linus Torvalds
From: Sudeep Holla <redacted>
Add KVM_ARM_VCPU_SPE_CTRL(KVM_ARM_VCPU_SPE_IRQ) to allow the user to set
the interrupt number for the buffer management interrupt.
[ Alexandru E: Split from "KVM: arm64: Add a new VCPU device control group
for SPE" ]
Signed-off-by: Sudeep Holla <redacted>
Signed-off-by: Alexandru Elisei <redacted>
---
Documentation/virt/kvm/devices/vcpu.rst | 19 ++++++
arch/arm64/include/asm/kvm_host.h | 2 +
arch/arm64/include/asm/kvm_spe.h | 10 +++
arch/arm64/include/uapi/asm/kvm.h | 1 +
arch/arm64/kvm/spe.c | 86 +++++++++++++++++++++++++
5 files changed, 118 insertions(+)
diff --git a/Documentation/virt/kvm/devices/vcpu.rst b/Documentation/virt/kvm/devices/vcpu.rst
index 85399c005197..05821d40849f 100644
--- a/Documentation/virt/kvm/devices/vcpu.rst
+++ b/Documentation/virt/kvm/devices/vcpu.rst@@ -166,3 +166,22 @@ including the layout of the stolen time structure. =============================== :Architectures: ARM64 + +4.1 ATTRIBUTE: KVM_ARM_VCPU_SPE_IRQ +----------------------------------- + +:Parameters: in kvm_device_attr.addr the address for the Profiling Buffer + management interrupt number as a pointer to an int + +Returns: + + ======= ====================================================== + -EBUSY Interrupt number already set for this VCPU + -EFAULT Error accessing the buffer management interrupt number + -EINVAL Invalid interrupt number + -ENXIO SPE not supported or not properly configured + ======= ====================================================== + +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.
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 948adb152104..7b957e439b3d 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h@@ -26,6 +26,7 @@ #include <asm/fpsimd.h> #include <asm/kvm.h> #include <asm/kvm_asm.h> +#include <asm/kvm_spe.h> #include <asm/thread_info.h> #define __KVM_HAVE_ARCH_INTC_INITIALIZED
@@ -353,6 +354,7 @@ struct kvm_vcpu_arch { struct vgic_cpu vgic_cpu; struct arch_timer_cpu timer_cpu; struct kvm_pmu pmu; + struct kvm_vcpu_spe spe; /* * Anything that is not used directly from assembly code goes
diff --git a/arch/arm64/include/asm/kvm_spe.h b/arch/arm64/include/asm/kvm_spe.h
index ce0f5b3f2027..2fe11868719d 100644
--- a/arch/arm64/include/asm/kvm_spe.h
+++ b/arch/arm64/include/asm/kvm_spe.h@@ -6,6 +6,8 @@ #ifndef __ARM64_KVM_SPE_H__ #define __ARM64_KVM_SPE_H__ +#include <linux/kvm.h> + #ifdef CONFIG_KVM_ARM_SPE DECLARE_STATIC_KEY_FALSE(kvm_spe_available);
@@ -14,6 +16,11 @@ static __always_inline bool kvm_supports_spe(void) return static_branch_likely(&kvm_spe_available); } +struct kvm_vcpu_spe { + bool initialized; /* SPE initialized for the VCPU */ + int irq_num; /* Buffer management interrut number */ +}; + void kvm_spe_init_supported_cpus(void); void kvm_spe_vm_init(struct kvm *kvm); int kvm_spe_check_supported_cpus(struct kvm_vcpu *vcpu);
@@ -24,6 +31,9 @@ int kvm_spe_has_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr); #else #define kvm_supports_spe() (false) +struct kvm_vcpu_spe { +}; + static inline void kvm_spe_init_supported_cpus(void) {} static inline void kvm_spe_vm_init(struct kvm *kvm) {} static inline int kvm_spe_check_supported_cpus(struct kvm_vcpu *vcpu) { return -ENOEXEC; }
diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
index 7159a1e23da2..c55d94a1a8f5 100644
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/arch/arm64/include/uapi/asm/kvm.h@@ -369,6 +369,7 @@ struct kvm_arm_copy_mte_tags { #define KVM_ARM_VCPU_PVTIME_CTRL 2 #define KVM_ARM_VCPU_PVTIME_IPA 0 #define KVM_ARM_VCPU_SPE_CTRL 3 +#define KVM_ARM_VCPU_SPE_IRQ 0 /* KVM_IRQ_LINE irq field index values */ #define KVM_ARM_IRQ_VCPU2_SHIFT 28
diff --git a/arch/arm64/kvm/spe.c b/arch/arm64/kvm/spe.c
index 56a3fdb35623..2fdb42e27675 100644
--- a/arch/arm64/kvm/spe.c
+++ b/arch/arm64/kvm/spe.c@@ -43,17 +43,103 @@ int kvm_spe_check_supported_cpus(struct kvm_vcpu *vcpu) return 0; } +static bool kvm_vcpu_supports_spe(struct kvm_vcpu *vcpu) +{ + if (!kvm_supports_spe()) + return false; + + if (!kvm_vcpu_has_spe(vcpu)) + return false; + + if (!irqchip_in_kernel(vcpu->kvm)) + return false; + + return true; +} + +static bool kvm_spe_irq_is_valid(struct kvm *kvm, int irq) +{ + struct kvm_vcpu *vcpu; + int i; + + if (!irq_is_ppi(irq)) + return -EINVAL; + + kvm_for_each_vcpu(i, vcpu, kvm) { + if (!vcpu->arch.spe.irq_num) + continue; + + if (vcpu->arch.spe.irq_num != irq) + return false; + } + + return true; +} + int kvm_spe_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr) { + if (!kvm_vcpu_supports_spe(vcpu)) + return -ENXIO; + + if (vcpu->arch.spe.initialized) + return -EBUSY; + + switch (attr->attr) { + case KVM_ARM_VCPU_SPE_IRQ: { + int __user *uaddr = (int __user *)(long)attr->addr; + int irq; + + if (vcpu->arch.spe.irq_num) + return -EBUSY; + + if (get_user(irq, uaddr)) + return -EFAULT; + + if (!kvm_spe_irq_is_valid(vcpu->kvm, irq)) + return -EINVAL; + + kvm_debug("Set KVM_ARM_VCPU_SPE_IRQ: %d\n", irq); + vcpu->arch.spe.irq_num = irq; + return 0; + } + } + return -ENXIO; } int kvm_spe_get_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr) { + if (!kvm_vcpu_supports_spe(vcpu)) + return -ENXIO; + + switch (attr->attr) { + case KVM_ARM_VCPU_SPE_IRQ: { + int __user *uaddr = (int __user *)(long)attr->addr; + int irq; + + if (!vcpu->arch.spe.irq_num) + return -ENXIO; + + irq = vcpu->arch.spe.irq_num; + if (put_user(irq, uaddr)) + return -EFAULT; + + return 0; + } + } + return -ENXIO; } int kvm_spe_has_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr) { + if (!kvm_vcpu_supports_spe(vcpu)) + return -ENXIO; + + switch(attr->attr) { + case KVM_ARM_VCPU_SPE_IRQ: + return 0; + } + return -ENXIO; }
--
2.33.0
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