Reflect the changes in the API due to the introduction of VGIC.
Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
---
Documentation/virtual/kvm/api.txt | 26 +++++++++++++++++++-------
1 file changed, 19 insertions(+), 7 deletions(-)
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 19d8915..d730b93 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -601,7 +601,7 @@ struct kvm_fpu {
4.24 KVM_CREATE_IRQCHIP
Capability: KVM_CAP_IRQCHIP
-Architectures: x86, ia64
+Architectures: x86, ia64, ARM
Type: vm ioctl
Parameters: none
Returns: 0 on success, -1 on error
@@ -609,14 +609,14 @@ Returns: 0 on success, -1 on error
Creates an interrupt controller model in the kernel. On x86, creates a virtual
ioapic, a virtual PIC (two PICs, nested), and sets up future vcpus to have a
local APIC. IRQ routing for GSIs 0-15 is set to both PIC and IOAPIC; GSI 16-23
-only go to the IOAPIC. On ia64, a IOSAPIC is created.
-
+only go to the IOAPIC. On ia64, a IOSAPIC is created. On ARM, a GIC is
+created.
4.25 KVM_IRQ_LINE
Capability: KVM_CAP_IRQCHIP
Architectures: x86, ia64, arm
-Type: vm ioctl
+Type: vm ioctl (and vcpu_ioctl on ARM)
Parameters: struct kvm_irq_level
Returns: 0 on success, -1 on error
@@ -625,9 +625,21 @@ 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 uses two types of interrupt lines per CPU: IRQ and FIQ. The value of the
-irq field should be (vcpu_index << 1) for IRQs and ((vcpu_index << 1) | 1) for
-FIQs. Level is used to raise/lower the line.
+ARM can signal an interrupt either at the CPU level, or at the
+in-kernel irqchip (GIC), with the following convention:
+
+- CPU signaling: ARM uses two types of interrupt lines per CPU: IRQ
+ and FIQ. The value of the irq field should be (vcpu_index << 1) for
+ IRQs and ((vcpu_index << 1) | 1) for FIQs. As there's a limit of 8
+ CPUs, irq is between 0 and 15. This is a vm_ioctl.
+
+- GIC signaling: If signaling a PPI, this is a vcpu_ioctl, and irq is
+ between 16 and 31. If signaling a SPI, this is a vm_ioctl, and irq
+ is above 31. Values between 0 and 15 would designate a SGI, which
+ should never be injected from user-space, thus avoiding any conflict
+ with the CPU signaling method.
+
+In both cases, level is used to raise/lower the line.
struct kvm_irq_level {
union {
--
1.7.11.4
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