On Wed, 28 Oct 2020 at 01:26, Alexandru Elisei <alexandru.elisei@xxxxxxx> wrote:
>
> From: Sudeep Holla <sudeep.holla@xxxxxxx>
>
> To configure the virtual SPE buffer management interrupt number, we use a
> VCPU kvm_device ioctl, encapsulating the KVM_ARM_VCPU_SPE_IRQ attribute
> within the KVM_ARM_VCPU_SPE_CTRL group.
>
> After configuring the SPE, userspace is required to call the VCPU ioctl
> with the attribute KVM_ARM_VCPU_SPE_INIT to initialize SPE on the VCPU.
>
> [Alexandru E: Fixed compilation errors, don't allow userspace to set the
> VCPU feature, removed unused functions, fixed mismatched
> descriptions, comments and error codes, reworked logic, rebased on
> top of v5.10-rc1]
>
> Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx>
> Signed-off-by: Alexandru Elisei <alexandru.elisei@xxxxxxx>
> ---
> Documentation/virt/kvm/devices/vcpu.rst | 40 ++++++++
> arch/arm64/include/uapi/asm/kvm.h | 3 +
> arch/arm64/kvm/Makefile | 1 +
> arch/arm64/kvm/guest.c | 9 ++
> arch/arm64/kvm/reset.c | 23 +++++
> arch/arm64/kvm/spe.c | 129 ++++++++++++++++++++++++
> include/kvm/arm_spe.h | 27 +++++
> include/uapi/linux/kvm.h | 1 +
> 8 files changed, 233 insertions(+)
> create mode 100644 arch/arm64/kvm/spe.c
>
> diff --git a/Documentation/virt/kvm/devices/vcpu.rst b/Documentation/virt/kvm/devices/vcpu.rst
> index 2acec3b9ef65..6135b9827fbe 100644
> --- a/Documentation/virt/kvm/devices/vcpu.rst
> +++ b/Documentation/virt/kvm/devices/vcpu.rst
> @@ -161,3 +161,43 @@ 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.rst for more information
> including the layout of the stolen time structure.
> +
> +4. GROUP: KVM_ARM_VCPU_SPE_CTRL
> +===============================
> +
> +:Architectures: ARM64
> +
> +4.1 ATTRIBUTE: KVM_ARM_VCPU_SPE_IRQ
> +-----------------------------------
> +
> +:Parameters: in kvm_device_attr.addr the address for the SPE buffer management
> + interrupt is a pointer to an int
> +
> +Returns:
> +
> + ======= ========================================================
> + -EBUSY The SPE buffer management interrupt is already set
> + -EINVAL Invalid SPE overflow interrupt number
> + -EFAULT Could not read the buffer management interrupt number
> + -ENXIO SPE not supported or not properly configured
> + ======= ========================================================
> +
> +A value describing the SPE (Statistical Profiling Extension) overflow interrupt
> +number for this vcpu. This interrupt should be a PPI and the interrupt type and
> +number must be same for each vcpu.
> +
> +4.2 ATTRIBUTE: KVM_ARM_VCPU_SPE_INIT
> +------------------------------------
> +
> +:Parameters: no additional parameter in kvm_device_attr.addr
> +
> +Returns:
> +
> + ======= ======================================================
> + -EBUSY SPE already initialized
> + -ENODEV GIC not initialized
> + -ENXIO SPE not supported or not properly configured
> + ======= ======================================================
> +
> +Request the initialization of the SPE. Must be done after initializing the
> +in-kernel irqchip and after setting the interrupt number for the VCPU.
> diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
> index 489e12304dbb..ca57dfb7abf0 100644
> --- a/arch/arm64/include/uapi/asm/kvm.h
> +++ b/arch/arm64/include/uapi/asm/kvm.h
> @@ -360,6 +360,9 @@ 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_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/Makefile b/arch/arm64/kvm/Makefile
> index 1504c81fbf5d..f6e76f64ffbe 100644
> --- a/arch/arm64/kvm/Makefile
> +++ b/arch/arm64/kvm/Makefile
> @@ -25,3 +25,4 @@ kvm-y := $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o $(KVM)/eventfd.o \
> vgic/vgic-its.o vgic/vgic-debug.o
>
> kvm-$(CONFIG_KVM_ARM_PMU) += pmu-emul.o
> +kvm-$(CONFIG_KVM_ARM_SPE) += spe.o
> diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
> index dfb5218137ca..2ba790eeb782 100644
> --- a/arch/arm64/kvm/guest.c
> +++ b/arch/arm64/kvm/guest.c
> @@ -926,6 +926,9 @@ int kvm_arm_vcpu_arch_set_attr(struct kvm_vcpu *vcpu,
> case KVM_ARM_VCPU_PVTIME_CTRL:
> ret = kvm_arm_pvtime_set_attr(vcpu, attr);
> break;
> + case KVM_ARM_VCPU_SPE_CTRL:
> + ret = kvm_arm_spe_set_attr(vcpu, attr);
> + break;
> default:
> ret = -ENXIO;
> break;
> @@ -949,6 +952,9 @@ int kvm_arm_vcpu_arch_get_attr(struct kvm_vcpu *vcpu,
> case KVM_ARM_VCPU_PVTIME_CTRL:
> ret = kvm_arm_pvtime_get_attr(vcpu, attr);
> break;
> + case KVM_ARM_VCPU_SPE_CTRL:
> + ret = kvm_arm_spe_get_attr(vcpu, attr);
> + break;
> default:
> ret = -ENXIO;
> break;
> @@ -972,6 +978,9 @@ int kvm_arm_vcpu_arch_has_attr(struct kvm_vcpu *vcpu,
> case KVM_ARM_VCPU_PVTIME_CTRL:
> ret = kvm_arm_pvtime_has_attr(vcpu, attr);
> break;
> + case KVM_ARM_VCPU_SPE_CTRL:
> + ret = kvm_arm_spe_has_attr(vcpu, attr);
> + break;
> default:
> ret = -ENXIO;
> break;
> diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
> index f32490229a4c..4dc205fa4be1 100644
> --- a/arch/arm64/kvm/reset.c
> +++ b/arch/arm64/kvm/reset.c
> @@ -87,6 +87,9 @@ int kvm_arch_vm_ioctl_check_extension(struct kvm *kvm, long ext)
> case KVM_CAP_ARM_PTRAUTH_GENERIC:
> r = system_has_full_ptr_auth();
> break;
> + case KVM_CAP_ARM_SPE:
> + r = kvm_arm_supports_spe();
> + break;
> default:
> r = 0;
> }
> @@ -223,6 +226,19 @@ static int kvm_vcpu_enable_ptrauth(struct kvm_vcpu *vcpu)
> return 0;
> }
>
> +static int kvm_vcpu_enable_spe(struct kvm_vcpu *vcpu)
> +{
> + if (!kvm_arm_supports_spe())
> + return -EINVAL;
> +
> + /* SPE is disabled if the PE is in AArch32 state */
> + if (test_bit(KVM_ARM_VCPU_EL1_32BIT, vcpu->arch.features))
> + return -EINVAL;
> +
> + vcpu->arch.flags |= KVM_ARM64_GUEST_HAS_SPE;
> + return 0;
> +}
> +
> /**
> * kvm_reset_vcpu - sets core registers and sys_regs to reset value
> * @vcpu: The VCPU pointer
> @@ -274,6 +290,13 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
> }
> }
>
> + if (test_bit(KVM_ARM_VCPU_SPE, vcpu->arch.features)) {
> + if (kvm_vcpu_enable_spe(vcpu)) {
> + ret = -EINVAL;
> + goto out;
> + }
> + }
> +
> switch (vcpu->arch.target) {
> default:
> if (test_bit(KVM_ARM_VCPU_EL1_32BIT, vcpu->arch.features)) {
> diff --git a/arch/arm64/kvm/spe.c b/arch/arm64/kvm/spe.c
> new file mode 100644
> index 000000000000..f91a52cd7cd3
> --- /dev/null
> +++ b/arch/arm64/kvm/spe.c
> @@ -0,0 +1,129 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2019 ARM Ltd.
> + */
> +
> +#include <linux/kvm.h>
> +#include <linux/kvm_host.h>
> +#include <linux/uaccess.h>
> +
> +#include <kvm/arm_spe.h>
> +#include <kvm/arm_vgic.h>
> +
> +static bool kvm_arm_vcpu_supports_spe(struct kvm_vcpu *vcpu)
> +{
> + if (!vcpu_has_spe(vcpu))
> + return false;
> +
> + if (!irqchip_in_kernel(vcpu->kvm))
> + return false;
> +
nit: should we move the irqchip_in_kernel() check to the caller?
> + return true;
> +}
> +
> +static int kvm_arm_spe_init(struct kvm_vcpu *vcpu)
> +{
> + if (!kvm_arm_spe_irq_initialized(vcpu))
> + return -ENXIO;
> +
> + if (!vgic_initialized(vcpu->kvm))
> + return -ENODEV;
> +
> + if (kvm_arm_spe_vcpu_initialized(vcpu))
> + return -EBUSY;
> +
> + if (kvm_vgic_set_owner(vcpu, vcpu->arch.spe_cpu.irq_num, &vcpu->arch.spe_cpu))
> + return -ENXIO;
> +
> + vcpu->arch.spe_cpu.initialized = true;
> +
> + return 0;
> +}
> +
> +static bool kvm_arm_spe_irq_is_valid(struct kvm *kvm, int irq)
> +{
> + int i;
> + struct kvm_vcpu *vcpu;
> +
> + /* The SPE overflow interrupt can be a PPI only */
> + if (!irq_is_ppi(irq))
> + return false;
> +
> + kvm_for_each_vcpu(i, vcpu, kvm) {
> + if (!kvm_arm_spe_irq_initialized(vcpu))
> + continue;
> +
> + if (vcpu->arch.spe_cpu.irq_num != irq)
> + return false;
> + }
> +
> + return true;
> +}
> +
> +int kvm_arm_spe_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
> +{
> + switch (attr->attr) {
> + case KVM_ARM_VCPU_SPE_IRQ: {
> + int __user *uaddr = (int __user *)(long)attr->addr;
> + int irq;
> +
> + if (!kvm_arm_vcpu_supports_spe(vcpu))
> + return -ENXIO;
> +
> + if (get_user(irq, uaddr))
> + return -EFAULT;
> +
> + if (!kvm_arm_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_cpu.irq_num = irq;
> +
> + return 0;
> + }
> + case KVM_ARM_VCPU_SPE_INIT:
> + return kvm_arm_spe_init(vcpu);
> + }
> +
> + return -ENXIO;
> +}
> +
> +int kvm_arm_spe_get_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
> +{
> + switch (attr->attr) {
> + case KVM_ARM_VCPU_SPE_IRQ: {
> + int __user *uaddr = (int __user *)(long)attr->addr;
> + int irq;
> +
> + if (!kvm_arm_vcpu_supports_spe(vcpu))
> + return -ENXIO;
> +
> + if (!kvm_arm_spe_irq_initialized(vcpu))
> + return -ENXIO;
> +
> + irq = vcpu->arch.spe_cpu.irq_num;
> + if (put_user(irq, uaddr))
> + return -EFAULT;
> +
> + return 0;
> + }
> + }
> +
> + return -ENXIO;
> +}
> +
> +int kvm_arm_spe_has_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
> +{
> + switch (attr->attr) {
> + case KVM_ARM_VCPU_SPE_IRQ:
> + fallthrough;
> + case KVM_ARM_VCPU_SPE_INIT:
> + if (kvm_arm_vcpu_supports_spe(vcpu))
> + return 0;
> + }
> +
> + return -ENXIO;
> +}
> diff --git a/include/kvm/arm_spe.h b/include/kvm/arm_spe.h
> index 46ec447ed013..0275e8097529 100644
> --- a/include/kvm/arm_spe.h
> +++ b/include/kvm/arm_spe.h
> @@ -18,11 +18,38 @@ struct kvm_spe_cpu {
> bool initialized; /* Feature is initialized on VCPU */
> };
>
> +#define kvm_arm_spe_irq_initialized(v) \
> + ((v)->arch.spe_cpu.irq_num >= VGIC_NR_SGIS && \
> + (v)->arch.spe_cpu.irq_num < VGIC_MAX_PRIVATE)
> +#define kvm_arm_spe_vcpu_initialized(v) ((v)->arch.spe_cpu.initialized)
> +
> +int kvm_arm_spe_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr);
> +int kvm_arm_spe_get_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr);
> +int kvm_arm_spe_has_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr);
> +
> #else
> #define kvm_arm_supports_spe() false
>
> struct kvm_spe_cpu {
> };
>
> +#define kvm_arm_spe_irq_initialized(v) false
> +#define kvm_arm_spe_vcpu_initialized(v) false
> +
> +static inline int kvm_arm_spe_set_attr(struct kvm_vcpu *vcpu,
> + struct kvm_device_attr *attr)
> +{
> + return -ENXIO;
> +}
> +static inline int kvm_arm_spe_get_attr(struct kvm_vcpu *vcpu,
> + struct kvm_device_attr *attr)
> +{
> + return -ENXIO;
> +}
> +static inline int kvm_arm_spe_has_attr(struct kvm_vcpu *vcpu,
> + struct kvm_device_attr *attr)
> +{
> + return -ENXIO;
> +}
> #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 ca41220b40b8..96228b823711 100644
> --- a/include/uapi/linux/kvm.h
> +++ b/include/uapi/linux/kvm.h
> @@ -1053,6 +1053,7 @@ struct kvm_ppc_resize_hpt {
> #define KVM_CAP_X86_USER_SPACE_MSR 188
> #define KVM_CAP_X86_MSR_FILTER 189
> #define KVM_CAP_ENFORCE_PV_FEATURE_CPUID 190
> +#define KVM_CAP_ARM_SPE 191
>
> #ifdef KVM_CAP_IRQ_ROUTING
>
> --
> 2.29.1
>
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