[PATCH v2 12/18] KVM: arm64: add a new vcpu device control group for SPEv1

From: Andrew Murray
Date: Fri Dec 20 2019 - 09:31:30 EST

From: Sudeep Holla <sudeep.holla@xxxxxxx>

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@xxxxxxx>
Signed-off-by: Andrew Murray <andrew.murray@xxxxxxx>
---
Documentation/virt/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 | 6 +
arch/arm64/kvm/reset.c | 3 +
include/kvm/arm_spe.h | 45 +++++++
include/uapi/linux/kvm.h | 1 +
virt/kvm/arm/arm.c | 1 +
virt/kvm/arm/spe.c | 163 ++++++++++++++++++++++++
10 files changed, 253 insertions(+), 1 deletion(-)
create mode 100644 virt/kvm/arm/spe.c

diff --git a/Documentation/virt/kvm/devices/vcpu.txt b/Documentation/virt/kvm/devices/vcpu.txt
index 6f3bd64a05b0..cefad056d677 100644
--- a/Documentation/virt/kvm/devices/vcpu.txt
+++ b/Documentation/virt/kvm/devices/vcpu.txt
@@ -74,3 +74,31 @@ Specifies the base address of the stolen time structure for this VCPU. The
base address must be 64 byte aligned and exist within a valid guest memory
region. See Documentation/virt/kvm/arm/pvtime.txt for more information
including the layout of the stolen time structure.
+
+4. GROUP: KVM_ARM_VCPU_SPE_V1_CTRL
+Architectures: ARM64
+
+4.1. 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.
+
+4.2 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 333c6491bec7..d00f450dc4cd 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -39,7 +39,7 @@

#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 820e5751ada7..905a73f30079 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;
@@ -326,6 +327,9 @@ struct kvm_vcpu_events {
#define KVM_ARM_VCPU_TIMER_IRQ_PTIMER 1
#define KVM_ARM_VCPU_PVTIME_CTRL 2
#define KVM_ARM_VCPU_PVTIME_IPA 0
+#define KVM_ARM_VCPU_SPE_V1_CTRL 3
+#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_VCPU2_SHIFT 28
diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile
index 5ffbdc39e780..526f3bf09321 100644
--- a/arch/arm64/kvm/Makefile
+++ b/arch/arm64/kvm/Makefile
@@ -37,3 +37,4 @@ 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 2fff06114a8f..50fea538b8bd 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -874,6 +874,8 @@ int kvm_arm_vcpu_arch_set_attr(struct kvm_vcpu *vcpu,
break;
case KVM_ARM_VCPU_PVTIME_CTRL:
ret = kvm_arm_pvtime_set_attr(vcpu, attr);
+ case KVM_ARM_VCPU_SPE_V1_CTRL:
+ ret = kvm_arm_spe_v1_set_attr(vcpu, attr);
break;
default:
ret = -ENXIO;
@@ -897,6 +899,8 @@ int kvm_arm_vcpu_arch_get_attr(struct kvm_vcpu *vcpu,
break;
case KVM_ARM_VCPU_PVTIME_CTRL:
ret = kvm_arm_pvtime_get_attr(vcpu, attr);
+ case KVM_ARM_VCPU_SPE_V1_CTRL:
+ ret = kvm_arm_spe_v1_get_attr(vcpu, attr);
break;
default:
ret = -ENXIO;
@@ -920,6 +924,8 @@ int kvm_arm_vcpu_arch_has_attr(struct kvm_vcpu *vcpu,
break;
case KVM_ARM_VCPU_PVTIME_CTRL:
ret = kvm_arm_pvtime_has_attr(vcpu, attr);
+ case KVM_ARM_VCPU_SPE_V1_CTRL:
+ ret = kvm_arm_spe_v1_has_attr(vcpu, attr);
break;
default:
ret = -ENXIO;
diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
index f4a8ae918827..cf17aff1489d 100644
--- a/arch/arm64/kvm/reset.c
+++ b/arch/arm64/kvm/reset.c
@@ -80,6 +80,9 @@ 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 30c40b1bc385..d1f3c564dfd0 100644
--- a/include/kvm/arm_spe.h
+++ b/include/kvm/arm_spe.h
@@ -8,6 +8,7 @@

#include <uapi/linux/kvm.h>
#include <linux/kvm_host.h>
+#include <linux/cpufeature.h>

struct kvm_spe {
int irq_num;
@@ -18,8 +19,52 @@ 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_num >= VGIC_NR_SGIS && \
+ (v)->arch.spe.irq_num <= VGIC_MAX_PRIVATE)
+
+static inline bool kvm_arm_support_spe_v1(void)
+{
+ u64 dfr0 = read_sanitised_ftr_reg(SYS_ID_AA64DFR0_EL1);
+
+ 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 f0a16b4adbbd..1a362c230e4a 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1009,6 +1009,7 @@ struct kvm_ppc_resize_hpt {
#define KVM_CAP_PPC_GUEST_DEBUG_SSTEP 176
#define KVM_CAP_ARM_NISV_TO_USER 177
#define KVM_CAP_ARM_INJECT_EXT_DABT 178
+#define KVM_CAP_ARM_SPE_V1 179

#ifdef KVM_CAP_IRQ_ROUTING

diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
index 12e0280291ce..340d2388ee2c 100644
--- a/virt/kvm/arm/arm.c
+++ b/virt/kvm/arm/arm.c
@@ -22,6 +22,7 @@
#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..83ac2cce2cc3
--- /dev/null
+++ b/virt/kvm/arm/spe.c
@@ -0,0 +1,163 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 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_num;
+
+ 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_num,
+ &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_num != 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_num = 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_num;
+ 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;
+}
--
2.21.0