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authorChristoffer Dall <cdall@cs.columbia.edu>2013-01-20 18:28:08 -0500
committerChristoffer Dall <c.dall@virtualopensystems.com>2013-01-23 13:29:12 -0500
commit86ce85352f0da7e1431ad8efcb04323819a620e7 (patch)
tree0f5a0a971b0092c9cfd74659254f76a4c7117294 /arch/arm/kvm/arm.c
parentd5d8184d35c990b1324d9b30bcd0e4e8aa08f56d (diff)
downloadvexpress-lsk-86ce85352f0da7e1431ad8efcb04323819a620e7.tar.gz
KVM: ARM: Inject IRQs and FIQs from userspace
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 <will.deacon@arm.com> Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
Diffstat (limited to 'arch/arm/kvm/arm.c')
-rw-r--r--arch/arm/kvm/arm.c65
1 files changed, 65 insertions, 0 deletions
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index d810afb6cb8..2101152c3a4 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
@@ -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)
{