[PATCH v2 12/15] KVM: arm64: add a new vcpu device control group for SPEv1

Sudeep Holla
2019-05-23T10:35:56Z

To configure the virtual SPEv1 overflow interrupt number, we use the
vcpu kvm_device ioctl, encapsulating the KVM_ARM_VCPU_SPE_V1_IRQ
attribute within the KVM_ARM_VCPU_SPE_V1_CTRL group.

After configuring the SPEv1, call the vcpu ioctl with attribute
KVM_ARM_VCPU_SPE_V1_INIT to initialize the SPEv1.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
---
Documentation/virtual/kvm/devices/vcpu.txt | 28 ++++
arch/arm64/include/asm/kvm_host.h | 2 +-
arch/arm64/include/uapi/asm/kvm.h | 4 +
arch/arm64/kvm/Makefile | 1 +
arch/arm64/kvm/guest.c | 9 ++
arch/arm64/kvm/reset.c | 3 +
include/kvm/arm_spe.h | 35 +++++
include/uapi/linux/kvm.h | 1 +
virt/kvm/arm/arm.c | 1 +
virt/kvm/arm/spe.c | 163 +++++++++++++++++++++
10 files changed, 246 insertions(+), 1 deletion(-)
create mode 100644 virt/kvm/arm/spe.c

diff --git a/Documentation/virtual/kvm/devices/vcpu.txt b/Documentation/virtual/kvm/devices/vcpu.txt
index 2b5dab16c4f2..d1ece488aeee 100644
--- a/Documentation/virtual/kvm/devices/vcpu.txt
+++ b/Documentation/virtual/kvm/devices/vcpu.txt
@@ -60,3 +60,31 @@ time to use the number provided for a given timer, overwriting any previously
configured values on other VCPUs. Userspace should configure the interrupt
numbers on at least one VCPU after creating all VCPUs and before running any
VCPUs.
+
+3. GROUP: KVM_ARM_VCPU_SPE_V1_CTRL
+Architectures: ARM64
+
+1.1. ATTRIBUTE: KVM_ARM_VCPU_SPE_V1_IRQ
+Parameters: in kvm_device_attr.addr the address for SPE buffer overflow interrupt
+ is a pointer to an int
+Returns: -EBUSY: The SPE overflow interrupt is already set
+ -ENXIO: The overflow interrupt not set when attempting to get it
+ -ENODEV: SPEv1 not supported
+ -EINVAL: Invalid SPE overflow interrupt number supplied or
+ trying to set the IRQ number without using an in-kernel
+ irqchip.
+
+A value describing the SPEv1 (Statistical Profiling Extension v1) overflow
+interrupt number for this vcpu. This interrupt should be PPI and the interrupt
+type and number must be same for each vcpu.
+
+1.2 ATTRIBUTE: KVM_ARM_VCPU_SPE_V1_INIT
+Parameters: no additional parameter in kvm_device_attr.addr
+Returns: -ENODEV: SPEv1 not supported or GIC not initialized
+ -ENXIO: SPEv1 not properly configured or in-kernel irqchip not
+ configured as required prior to calling this attribute
+ -EBUSY: SPEv1 already initialized
+
+Request the initialization of the SPEv1. If using the SPEv1 with an in-kernel
+virtual GIC implementation, this must be done after initializing the in-kernel
+irqchip.
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 6921fdfd477b..fc4ead0774b3 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -50,7 +50,7 @@

#define KVM_MAX_VCPUS VGIC_V3_MAX_CPUS

-#define KVM_VCPU_MAX_FEATURES 7
+#define KVM_VCPU_MAX_FEATURES 8

#define KVM_REQ_SLEEP \
KVM_ARCH_REQ_FLAGS(0, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
index 7b7ac0f6cec9..4c9e168de896 100644
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/arch/arm64/include/uapi/asm/kvm.h
@@ -106,6 +106,7 @@ struct kvm_regs {
#define KVM_ARM_VCPU_SVE 4 /* enable SVE for this CPU */
#define KVM_ARM_VCPU_PTRAUTH_ADDRESS 5 /* VCPU uses address authentication */
#define KVM_ARM_VCPU_PTRAUTH_GENERIC 6 /* VCPU uses generic authentication */
+#define KVM_ARM_VCPU_SPE_V1 7 /* Support guest SPEv1 */

struct kvm_vcpu_init {
__u32 target;
@@ -306,6 +307,9 @@ struct kvm_vcpu_events {
#define KVM_ARM_VCPU_TIMER_CTRL 1
#define KVM_ARM_VCPU_TIMER_IRQ_VTIMER 0
#define KVM_ARM_VCPU_TIMER_IRQ_PTIMER 1
+#define KVM_ARM_VCPU_SPE_V1_CTRL 2
+#define KVM_ARM_VCPU_SPE_V1_IRQ 0
+#define KVM_ARM_VCPU_SPE_V1_INIT 1

/* KVM_IRQ_LINE irq field index values */
#define KVM_ARM_IRQ_TYPE_SHIFT 24
diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile
index 3ac1a64d2fb9..1ba6154dd8e1 100644
--- a/arch/arm64/kvm/Makefile
+++ b/arch/arm64/kvm/Makefile
@@ -35,3 +35,4 @@ kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-debug.o
kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/irqchip.o
kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/arch_timer.o
kvm-$(CONFIG_KVM_ARM_PMU) += $(KVM)/arm/pmu.o
+kvm-$(CONFIG_KVM_ARM_SPE) += $(KVM)/arm/spe.o
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index 3ae2f82fca46..02c28a7eb332 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -848,6 +848,9 @@ int kvm_arm_vcpu_arch_set_attr(struct kvm_vcpu *vcpu,
case KVM_ARM_VCPU_TIMER_CTRL:
ret = kvm_arm_timer_set_attr(vcpu, attr);
break;
+ case KVM_ARM_VCPU_SPE_V1_CTRL:
+ ret = kvm_arm_spe_v1_set_attr(vcpu, attr);
+ break;
default:
ret = -ENXIO;
break;
@@ -868,6 +871,9 @@ int kvm_arm_vcpu_arch_get_attr(struct kvm_vcpu *vcpu,
case KVM_ARM_VCPU_TIMER_CTRL:
ret = kvm_arm_timer_get_attr(vcpu, attr);
break;
+ case KVM_ARM_VCPU_SPE_V1_CTRL:
+ ret = kvm_arm_spe_v1_get_attr(vcpu, attr);
+ break;
default:
ret = -ENXIO;
break;
@@ -888,6 +894,9 @@ int kvm_arm_vcpu_arch_has_attr(struct kvm_vcpu *vcpu,
case KVM_ARM_VCPU_TIMER_CTRL:
ret = kvm_arm_timer_has_attr(vcpu, attr);
break;
+ case KVM_ARM_VCPU_SPE_V1_CTRL:
+ ret = kvm_arm_spe_v1_has_attr(vcpu, attr);
+ break;
default:
ret = -ENXIO;
break;
diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
index 1140b4485575..33ce5248613e 100644
--- a/arch/arm64/kvm/reset.c
+++ b/arch/arm64/kvm/reset.c
@@ -91,6 +91,9 @@ int kvm_arch_vm_ioctl_check_extension(struct kvm *kvm, long ext)
case KVM_CAP_ARM_INJECT_SERROR_ESR:
r = cpus_have_const_cap(ARM64_HAS_RAS_EXTN);
break;
+ case KVM_CAP_ARM_SPE_V1:
+ r = kvm_arm_support_spe_v1();
+ break;
case KVM_CAP_SET_GUEST_DEBUG:
case KVM_CAP_VCPU_ATTRIBUTES:
r = 1;
diff --git a/include/kvm/arm_spe.h b/include/kvm/arm_spe.h
index fdcb0df1e0fd..8c2e8f10a965 100644
--- a/include/kvm/arm_spe.h
+++ b/include/kvm/arm_spe.h
@@ -19,6 +19,9 @@ struct kvm_spe {
#ifdef CONFIG_KVM_ARM_SPE

#define kvm_arm_spe_v1_ready(v) ((v)->arch.spe.ready)
+#define kvm_arm_spe_irq_initialized(v) \
+ ((v)->arch.spe.irq >= VGIC_NR_SGIS && \
+ (v)->arch.spe.irq <= VGIC_MAX_PRIVATE)

static inline bool kvm_arm_support_spe_v1(void)
{
@@ -27,10 +30,42 @@ static inline bool kvm_arm_support_spe_v1(void)
return !!cpuid_feature_extract_unsigned_field(dfr0,
ID_AA64DFR0_PMSVER_SHIFT);
}
+
+int kvm_arm_spe_v1_set_attr(struct kvm_vcpu *vcpu,
+ struct kvm_device_attr *attr);
+int kvm_arm_spe_v1_get_attr(struct kvm_vcpu *vcpu,
+ struct kvm_device_attr *attr);
+int kvm_arm_spe_v1_has_attr(struct kvm_vcpu *vcpu,
+ struct kvm_device_attr *attr);
+int kvm_arm_spe_v1_enable(struct kvm_vcpu *vcpu);
#else

#define kvm_arm_spe_v1_ready(v) (false)
#define kvm_arm_support_spe_v1() (false)
+#define kvm_arm_spe_irq_initialized(v) (false)
+
+static inline int kvm_arm_spe_v1_set_attr(struct kvm_vcpu *vcpu,
+ struct kvm_device_attr *attr)
+{
+ return -ENXIO;
+}
+
+static inline int kvm_arm_spe_v1_get_attr(struct kvm_vcpu *vcpu,
+ struct kvm_device_attr *attr)
+{
+ return -ENXIO;
+}
+
+static inline int kvm_arm_spe_v1_has_attr(struct kvm_vcpu *vcpu,
+ struct kvm_device_attr *attr)
+{
+ return -ENXIO;
+}
+
+static inline int kvm_arm_spe_v1_enable(struct kvm_vcpu *vcpu)
+{
+ return 0;
+}
#endif /* CONFIG_KVM_ARM_SPE */

#endif /* __ASM_ARM_KVM_SPE_H */
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 2fe12b40d503..698bcc2f96e3 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -993,6 +993,7 @@ struct kvm_ppc_resize_hpt {
#define KVM_CAP_ARM_SVE 170
#define KVM_CAP_ARM_PTRAUTH_ADDRESS 171
#define KVM_CAP_ARM_PTRAUTH_GENERIC 172
+#define KVM_CAP_ARM_SPE_V1 173

#ifdef KVM_CAP_IRQ_ROUTING

diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
index 90cedebaeb94..c5b711ef1cf8 100644
--- a/virt/kvm/arm/arm.c
+++ b/virt/kvm/arm/arm.c
@@ -34,6 +34,7 @@
#include <trace/events/kvm.h>
#include <kvm/arm_pmu.h>
#include <kvm/arm_psci.h>
+#include <kvm/arm_spe.h>

#define CREATE_TRACE_POINTS
#include "trace.h"
diff --git a/virt/kvm/arm/spe.c b/virt/kvm/arm/spe.c
new file mode 100644
index 000000000000..87f02ed92426
--- /dev/null
+++ b/virt/kvm/arm/spe.c
@@ -0,0 +1,163 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2018 ARM Ltd.
+ */
+
+#include <linux/cpu.h>
+#include <linux/kvm.h>
+#include <linux/kvm_host.h>
+#include <linux/uaccess.h>
+#include <asm/kvm_emulate.h>
+#include <kvm/arm_spe.h>
+#include <kvm/arm_vgic.h>
+
+int kvm_arm_spe_v1_enable(struct kvm_vcpu *vcpu)
+{
+ if (!vcpu->arch.spe.created)
+ return 0;
+
+ /*
+ * A valid interrupt configuration for the SPE is either to have a
+ * properly configured interrupt number and using an in-kernel irqchip.
+ */
+ if (irqchip_in_kernel(vcpu->kvm)) {
+ int irq = vcpu->arch.spe.irq;
+
+ if (!kvm_arm_spe_irq_initialized(vcpu))
+ return -EINVAL;
+
+ if (!irq_is_ppi(irq))
+ return -EINVAL;
+ }
+
+ vcpu->arch.spe.ready = true;
+
+ return 0;
+}
+
+static int kvm_arm_spe_v1_init(struct kvm_vcpu *vcpu)
+{
+ if (!kvm_arm_support_spe_v1())
+ return -ENODEV;
+
+ if (!test_bit(KVM_ARM_VCPU_SPE_V1, vcpu->arch.features))
+ return -ENXIO;
+
+ if (vcpu->arch.spe.created)
+ return -EBUSY;
+
+ if (irqchip_in_kernel(vcpu->kvm)) {
+ int ret;
+
+ /*
+ * If using the SPE with an in-kernel virtual GIC
+ * implementation, we require the GIC to be already
+ * initialized when initializing the SPE.
+ */
+ if (!vgic_initialized(vcpu->kvm))
+ return -ENODEV;
+
+ ret = kvm_vgic_set_owner(vcpu, vcpu->arch.spe.irq,
+ &vcpu->arch.spe);
+ if (ret)
+ return ret;
+ }
+
+ vcpu->arch.spe.created = true;
+ return 0;
+}
+
+/*
+ * For one VM the interrupt type must be same for each vcpu.
+ * As a PPI, the interrupt number is the same for all vcpus,
+ * while as an SPI it must be a separate number per vcpu.
+ */
+static bool spe_irq_is_valid(struct kvm *kvm, int irq)
+{
+ int i;
+ struct kvm_vcpu *vcpu;
+
+ kvm_for_each_vcpu(i, vcpu, kvm) {
+ if (!kvm_arm_spe_irq_initialized(vcpu))
+ continue;
+
+ if (vcpu->arch.spe.irq != irq)
+ return false;
+ }
+
+ return true;
+}
+
+int kvm_arm_spe_v1_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
+{
+ switch (attr->attr) {
+ case KVM_ARM_VCPU_SPE_V1_IRQ: {
+ int __user *uaddr = (int __user *)(long)attr->addr;
+ int irq;
+
+ if (!irqchip_in_kernel(vcpu->kvm))
+ return -EINVAL;
+
+ if (!test_bit(KVM_ARM_VCPU_SPE_V1, vcpu->arch.features))
+ return -ENODEV;
+
+ if (get_user(irq, uaddr))
+ return -EFAULT;
+
+ /* The SPE overflow interrupt can be a PPI only */
+ if (!(irq_is_ppi(irq)))
+ return -EINVAL;
+
+ if (!spe_irq_is_valid(vcpu->kvm, irq))
+ return -EINVAL;
+
+ if (kvm_arm_spe_irq_initialized(vcpu))
+ return -EBUSY;
+
+ kvm_debug("Set kvm ARM SPE irq: %d\n", irq);
+ vcpu->arch.spe.irq = irq;
+ return 0;
+ }
+ case KVM_ARM_VCPU_SPE_V1_INIT:
+ return kvm_arm_spe_v1_init(vcpu);
+ }
+
+ return -ENXIO;
+}
+
+int kvm_arm_spe_v1_get_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
+{
+ switch (attr->attr) {
+ case KVM_ARM_VCPU_SPE_V1_IRQ: {
+ int __user *uaddr = (int __user *)(long)attr->addr;
+ int irq;
+
+ if (!irqchip_in_kernel(vcpu->kvm))
+ return -EINVAL;
+
+ if (!test_bit(KVM_ARM_VCPU_SPE_V1, vcpu->arch.features))
+ return -ENODEV;
+
+ if (!kvm_arm_spe_irq_initialized(vcpu))
+ return -ENXIO;
+
+ irq = vcpu->arch.spe.irq;
+ return put_user(irq, uaddr);
+ }
+ }
+
+ return -ENXIO;
+}
+
+int kvm_arm_spe_v1_has_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
+{
+ switch (attr->attr) {
+ case KVM_ARM_VCPU_SPE_V1_IRQ:
+ case KVM_ARM_VCPU_SPE_V1_INIT:
+ if (kvm_arm_support_spe_v1() &&
+ test_bit(KVM_ARM_VCPU_SPE_V1, vcpu->arch.features))
+ return 0;
+ }
+
+ return -ENXIO;
+}