[PATCH v4 07/14] KVM: ARM: Inject IRQs and FIQs from userspace
From: Will Deacon <hidden>
Date: 2012-11-19 14:55:46
Also in:
kvm
On Sat, Nov 10, 2012 at 03:42:59PM +0000, Christoffer Dall wrote:
From: Christoffer Dall <redacted>
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: Marcelo Tosatti <redacted>
Signed-off-by: Christoffer Dall <redacted>[...]
quoted hunk ↗ jump to hunk
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index 5ac3132..15e2ab1 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c@@ -24,6 +24,7 @@ #include <linux/fs.h> #include <linux/mman.h> #include <linux/sched.h> +#include <linux/kvm.h> #include <trace/events/kvm.h> #define CREATE_TRACE_POINTS@@ -272,6 +273,7 @@ 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)@@ -312,6 +314,74 @@ 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 || + irq_type == KVM_ARM_IRQ_TYPE_PPI) { + if (vcpu_idx >= nrcpus) + return -EINVAL; + + vcpu = kvm_get_vcpu(kvm, vcpu_idx); + if (!vcpu) + return -EINVAL; + } + + switch (irq_type) { + case KVM_ARM_IRQ_TYPE_CPU: + if (irq_num > KVM_ARM_IRQ_CPU_FIQ) + return -EINVAL; + + return vcpu_interrupt_line(vcpu, irq_num, level); + } + + return -EINVAL; +}
Holy cyclomatic complexity Batman! Any way this can be cleaned up? Will