From 86ce85352f0da7e1431ad8efcb04323819a620e7 Mon Sep 17 00:00:00 2001 From: Christoffer Dall Date: Sun, 20 Jan 2013 18:28:08 -0500 Subject: [PATCH] KVM: ARM: Inject IRQs and FIQs from userspace MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit All interrupt injection is now based on the VM ioctl KVM_IRQ_LINE. This works semantically well for the GIC as we in fact raise/lower a line on a machine component (the gic). The IOCTL uses the follwing struct. struct kvm_irq_level { union { __u32 irq; /* GSI */ __s32 status; /* not used for KVM_IRQ_LEVEL */ }; __u32 level; /* 0 or 1 */ }; ARM can signal an interrupt either at the CPU level, or at the in-kernel irqchip (GIC), and for in-kernel irqchip can tell the GIC to use PPIs designated for specific cpus. The irq field is interpreted like this:  bits: | 31 ... 24 | 23 ... 16 | 15 ... 0 | field: | irq_type | vcpu_index | irq_number | The irq_type field has the following values: - irq_type[0]: out-of-kernel GIC: irq_number 0 is IRQ, irq_number 1 is FIQ - irq_type[1]: in-kernel GIC: SPI, irq_number between 32 and 1019 (incl.) (the vcpu_index field is ignored) - irq_type[2]: in-kernel GIC: PPI, irq_number between 16 and 31 (incl.) The irq_number thus corresponds to the irq ID in as in the GICv2 specs. This is documented in Documentation/kvm/api.txt. Reviewed-by: Will Deacon Reviewed-by: Marcelo Tosatti Signed-off-by: Christoffer Dall --- Documentation/virtual/kvm/api.txt | 25 ++++++++++-- arch/arm/include/asm/kvm_arm.h | 1 + arch/arm/include/uapi/asm/kvm.h | 21 ++++++++++ arch/arm/kvm/arm.c | 65 +++++++++++++++++++++++++++++++ arch/arm/kvm/trace.h | 25 ++++++++++++ include/uapi/linux/kvm.h | 1 + 6 files changed, 134 insertions(+), 4 deletions(-) diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 4237c27ea612..505049299298 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -615,15 +615,32 @@ created. 4.25 KVM_IRQ_LINE Capability: KVM_CAP_IRQCHIP -Architectures: x86, ia64 +Architectures: x86, ia64, arm Type: vm ioctl Parameters: struct kvm_irq_level Returns: 0 on success, -1 on error Sets the level of a GSI input to the interrupt controller model in the kernel. -Requires that an interrupt controller model has been previously created with -KVM_CREATE_IRQCHIP. Note that edge-triggered interrupts require the level -to be set to 1 and then back to 0. +On some architectures it is required that an interrupt controller model has +been previously created with KVM_CREATE_IRQCHIP. Note that edge-triggered +interrupts require the level to be set to 1 and then back to 0. + +ARM can signal an interrupt either at the CPU level, or at the in-kernel irqchip +(GIC), and for in-kernel irqchip can tell the GIC to use PPIs designated for +specific cpus. The irq field is interpreted like this: + +  bits: | 31 ... 24 | 23 ... 16 | 15 ... 0 | + field: | irq_type | vcpu_index | irq_id | + +The irq_type field has the following values: +- irq_type[0]: out-of-kernel GIC: irq_id 0 is IRQ, irq_id 1 is FIQ +- irq_type[1]: in-kernel GIC: SPI, irq_id between 32 and 1019 (incl.) + (the vcpu_index field is ignored) +- irq_type[2]: in-kernel GIC: PPI, irq_id between 16 and 31 (incl.) + +(The irq_id field thus corresponds nicely to the IRQ ID in the ARM GIC specs) + +In both cases, level is used to raise/lower the line. struct kvm_irq_level { union { diff --git a/arch/arm/include/asm/kvm_arm.h b/arch/arm/include/asm/kvm_arm.h index 8875b3f605a7..d64b5250ad4e 100644 --- a/arch/arm/include/asm/kvm_arm.h +++ b/arch/arm/include/asm/kvm_arm.h @@ -68,6 +68,7 @@ #define HCR_GUEST_MASK (HCR_TSC | HCR_TSW | HCR_TWI | HCR_VM | HCR_BSU_IS | \ HCR_FB | HCR_TAC | HCR_AMO | HCR_IMO | HCR_FMO | \ HCR_SWIO | HCR_TIDCP) +#define HCR_VIRT_EXCP_MASK (HCR_VA | HCR_VI | HCR_VF) /* Hyp System Control Register (HSCTLR) bits */ #define HSCTLR_TE (1 << 30) diff --git a/arch/arm/include/uapi/asm/kvm.h b/arch/arm/include/uapi/asm/kvm.h index 1083327b5fcd..53f45f146875 100644 --- a/arch/arm/include/uapi/asm/kvm.h +++ b/arch/arm/include/uapi/asm/kvm.h @@ -23,6 +23,7 @@ #include #define __KVM_HAVE_GUEST_DEBUG +#define __KVM_HAVE_IRQ_LINE #define KVM_REG_SIZE(id) \ (1U << (((id) & KVM_REG_SIZE_MASK) >> KVM_REG_SIZE_SHIFT)) @@ -103,4 +104,24 @@ struct kvm_arch_memory_slot { #define KVM_REG_ARM_CORE (0x0010 << KVM_REG_ARM_COPROC_SHIFT) #define KVM_REG_ARM_CORE_REG(name) (offsetof(struct kvm_regs, name) / 4) +/* KVM_IRQ_LINE irq field index values */ +#define KVM_ARM_IRQ_TYPE_SHIFT 24 +#define KVM_ARM_IRQ_TYPE_MASK 0xff +#define KVM_ARM_IRQ_VCPU_SHIFT 16 +#define KVM_ARM_IRQ_VCPU_MASK 0xff +#define KVM_ARM_IRQ_NUM_SHIFT 0 +#define KVM_ARM_IRQ_NUM_MASK 0xffff + +/* irq_type field */ +#define KVM_ARM_IRQ_TYPE_CPU 0 +#define KVM_ARM_IRQ_TYPE_SPI 1 +#define KVM_ARM_IRQ_TYPE_PPI 2 + +/* out-of-kernel GIC cpu interrupt injection irq_number field */ +#define KVM_ARM_IRQ_CPU_IRQ 0 +#define KVM_ARM_IRQ_CPU_FIQ 1 + +/* Highest supported SPI, from VGIC_NR_IRQS */ +#define KVM_ARM_IRQ_GIC_MAX 127 + #endif /* __ARM_KVM_H__ */ diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index d810afb6cb84..2101152c3a4b 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -24,6 +24,7 @@ #include #include #include +#include #include #define CREATE_TRACE_POINTS @@ -284,6 +285,7 @@ void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) { + vcpu->cpu = cpu; } void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) @@ -319,6 +321,69 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) return -EINVAL; } +static int vcpu_interrupt_line(struct kvm_vcpu *vcpu, int number, bool level) +{ + int bit_index; + bool set; + unsigned long *ptr; + + if (number == KVM_ARM_IRQ_CPU_IRQ) + bit_index = __ffs(HCR_VI); + else /* KVM_ARM_IRQ_CPU_FIQ */ + bit_index = __ffs(HCR_VF); + + ptr = (unsigned long *)&vcpu->arch.irq_lines; + if (level) + set = test_and_set_bit(bit_index, ptr); + else + set = test_and_clear_bit(bit_index, ptr); + + /* + * If we didn't change anything, no need to wake up or kick other CPUs + */ + if (set == level) + return 0; + + /* + * The vcpu irq_lines field was updated, wake up sleeping VCPUs and + * trigger a world-switch round on the running physical CPU to set the + * virtual IRQ/FIQ fields in the HCR appropriately. + */ + kvm_vcpu_kick(vcpu); + + return 0; +} + +int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level) +{ + u32 irq = irq_level->irq; + unsigned int irq_type, vcpu_idx, irq_num; + int nrcpus = atomic_read(&kvm->online_vcpus); + struct kvm_vcpu *vcpu = NULL; + bool level = irq_level->level; + + irq_type = (irq >> KVM_ARM_IRQ_TYPE_SHIFT) & KVM_ARM_IRQ_TYPE_MASK; + vcpu_idx = (irq >> KVM_ARM_IRQ_VCPU_SHIFT) & KVM_ARM_IRQ_VCPU_MASK; + irq_num = (irq >> KVM_ARM_IRQ_NUM_SHIFT) & KVM_ARM_IRQ_NUM_MASK; + + trace_kvm_irq_line(irq_type, vcpu_idx, irq_num, irq_level->level); + + if (irq_type != KVM_ARM_IRQ_TYPE_CPU) + return -EINVAL; + + if (vcpu_idx >= nrcpus) + return -EINVAL; + + vcpu = kvm_get_vcpu(kvm, vcpu_idx); + if (!vcpu) + return -EINVAL; + + if (irq_num > KVM_ARM_IRQ_CPU_FIQ) + return -EINVAL; + + return vcpu_interrupt_line(vcpu, irq_num, level); +} + long kvm_arch_vcpu_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) { diff --git a/arch/arm/kvm/trace.h b/arch/arm/kvm/trace.h index 862b2cc12fbe..105d1f79909a 100644 --- a/arch/arm/kvm/trace.h +++ b/arch/arm/kvm/trace.h @@ -39,6 +39,31 @@ TRACE_EVENT(kvm_exit, TP_printk("PC: 0x%08lx", __entry->vcpu_pc) ); +TRACE_EVENT(kvm_irq_line, + TP_PROTO(unsigned int type, int vcpu_idx, int irq_num, int level), + TP_ARGS(type, vcpu_idx, irq_num, level), + + TP_STRUCT__entry( + __field( unsigned int, type ) + __field( int, vcpu_idx ) + __field( int, irq_num ) + __field( int, level ) + ), + + TP_fast_assign( + __entry->type = type; + __entry->vcpu_idx = vcpu_idx; + __entry->irq_num = irq_num; + __entry->level = level; + ), + + TP_printk("Inject %s interrupt (%d), vcpu->idx: %d, num: %d, level: %d", + (__entry->type == KVM_ARM_IRQ_TYPE_CPU) ? "CPU" : + (__entry->type == KVM_ARM_IRQ_TYPE_PPI) ? "VGIC PPI" : + (__entry->type == KVM_ARM_IRQ_TYPE_SPI) ? "VGIC SPI" : "UNKNOWN", + __entry->type, __entry->vcpu_idx, __entry->irq_num, __entry->level) +); + TRACE_EVENT(kvm_unmap_hva, TP_PROTO(unsigned long hva), TP_ARGS(hva), diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 24978d525c6e..dc63665e73ad 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -115,6 +115,7 @@ struct kvm_irq_level { * ACPI gsi notion of irq. * For IA-64 (APIC model) IOAPIC0: irq 0-23; IOAPIC1: irq 24-47.. * For X86 (standard AT mode) PIC0/1: irq 0-15. IOAPIC0: 0-23.. + * For ARM: See Documentation/virtual/kvm/api.txt */ union { __u32 irq; -- 2.20.1