[RFC PATCH v4 21/39] KVM: arm64: Add SPE VCPU device attribute to set the interrupt number
From: Alexandru Elisei
Date: Wed Aug 25 2021 - 12:18:15 EST
From: Sudeep Holla <sudeep.holla@xxxxxxx>
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 <sudeep.holla@xxxxxxx>
Signed-off-by: Alexandru Elisei <alexandru.elisei@xxxxxxx>
---
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