[RFC PATCH 1/3] KVM: ARM: Introduce KVM_INIT_IRQCHIP ioctl

[Christoffer Dall <c.dall@virtualopensystems.com>]

Used to initialize the in-kernel interrupt controller. On ARM we need to
map the virtual generic interrupt controller (vGIC) into Hyp the guest's
physicall address space so the guest can access the virtual cpu
interface. This must be done after the IRQ chips is create and after a
base address has been provided for the emulated platform (patch is
following), but before the CPU is initally run.

Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
---
 Documentation/virtual/kvm/api.txt |   16 ++++++++++++++++
 arch/arm/kvm/arm.c                |    1 +
 include/linux/kvm.h               |    3 +++
 3 files changed, 20 insertions(+)

diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 25eacc6..26e953d 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -2102,6 +2102,22 @@ This ioctl returns the guest registers that are supported for the
 KVM_GET_ONE_REG/KVM_SET_ONE_REG calls.
 
 
+4.79 KVM_INIT_IRQCHIP
+
+Capability: KVM_CAP_INIT_IRQCHIP
+Architectures: arm
+Type: vm ioctl
+Parameters: none
+Returns: 0 on success, -1 on error
+
+Initialize the in-kernel interrupt controller. On ARM we need to map the
+virtual generic interrupt controller (vGIC) into Hyp the guest's physicall
+address space so the guest can access the virtual cpu interface. This must be
+done after the IRQ chips is create and after a base address has been provided
+for the emulated platofrm (see KVM_SET_DEVICE_ADDRESS), but before the CPU is
+initally run.
+
+
 5. The kvm_run structure
 ------------------------
 
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index f8c377b..85c76e4 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -195,6 +195,7 @@ int kvm_dev_ioctl_check_extension(long ext)
 	switch (ext) {
 #ifdef CONFIG_KVM_ARM_VGIC
 	case KVM_CAP_IRQCHIP:
+	case KVM_CAP_INIT_IRQCHIP:
 		r = vgic_present;
 		break;
 #endif
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 8091b1d..90ee023 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -626,6 +626,7 @@ struct kvm_ppc_smmu_info {
 #ifdef __KVM_HAVE_READONLY_MEM
 #define KVM_CAP_READONLY_MEM 81
 #endif
+#define KVM_CAP_INIT_IRQCHIP 82
 
 #ifdef KVM_CAP_IRQ_ROUTING
 
@@ -839,6 +840,8 @@ struct kvm_s390_ucas_mapping {
 #define KVM_PPC_GET_SMMU_INFO	  _IOR(KVMIO,  0xa6, struct kvm_ppc_smmu_info)
 /* Available with KVM_CAP_PPC_ALLOC_HTAB */
 #define KVM_PPC_ALLOCATE_HTAB	  _IOWR(KVMIO, 0xa7, __u32)
+/* Available with KVM_CAP_INIT_IRQCHIP */
+#define KVM_INIT_IRQCHIP	  _IO(KVMIO,   0xa8)
 
 /*
  * ioctls for vcpu fds
-- 
1.7.9.5