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>

1 files changed, 25 insertions, 0 deletions

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),