This adds a new ioctl, KVM_SET_IRQ_ARCHITECTURE, which is intended to
be called by userspace to specify that it wishes the kernel to emulate
a specific interrupt controller architecture. This doesn't imply the
creation of any specific device, but does indicate that when vcpus are
created, space for per-vcpu interrupt controller state should be
allocated. Having this ioctl enables userspace to defer creation of
the actual interrupt controller device(s) until after the vcpus are
created.
The KVM_SET_IRQ_ARCHITECTURE ioctl takes a single 32-bit unsigned int
as its parameter. Values for this parameter will be defined in
subsequent patches. The value of 0 means no in-kernel interrupt
controller emulation.
In order to ensure that this ioctl will fail once any vcpu has been
created, we use an arch.vcpus_created field to indicate that vcpu
creation has commenced. We don't use the online_vcpus field because
that is only incremented after vcpu creation; if we used that there
would be a window during the first KVM_CREATE_VCPU ioctl where the
first vcpu had been created but the interrupt architecture could still
be changed.
Signed-off-by: Paul Mackerras <pau...@samba.org>
---
So, should this all be done in generic code?
Documentation/virtual/kvm/api.txt | 22 ++++++++++++
arch/powerpc/include/asm/kvm_host.h | 2 ++
arch/powerpc/kvm/powerpc.c | 66 +++++++++++++++++++++++++++++++++--
include/uapi/linux/kvm.h | 3 ++
4 files changed, 90 insertions(+), 3 deletions(-)
diff --git a/Documentation/virtual/kvm/api.txt
b/Documentation/virtual/kvm/api.txt
index cce500a..d550313 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -2126,6 +2126,28 @@ header; first `n_valid' valid entries with contents from
the data
written, then `n_invalid' invalid entries, invalidating any previously
valid entries found.
+4.79 KVM_SET_IRQ_ARCHITECTURE
+
+Capability: KVM_CAP_IRQ_ARCH
+Architecture: powerpc
+Type: vm ioctl
+Parameters: Pointer to u32 (in)
+Returns: 0 on success, -1 on error
+
+This is called before any vcpus are created, if in-kernel interrupt
+controller emulation is desired, to specify what overall interrupt
+controller architecture should be emulated. Having this called before
+any vcpus are created allows per-vcpu interrupt controller state to be
+allocated at vcpu creation time, and allows the creation of the actual
+interrupt controller device to be deferred until after the vcpus are
+created.
+
+The parameter is a 32-bit unsigned integer specifying the
+architecture, or the value 0 to specify that no emulation should be
+done. If the requested architecture is not supported by the kernel,
+this ioctl returns an EINVAL error. Otherwise, if this ioctl is
+called after any vcpus have been created, it returns an EBUSY error.
+
5. The kvm_run structure
------------------------
diff --git a/arch/powerpc/include/asm/kvm_host.h
b/arch/powerpc/include/asm/kvm_host.h
index 8a72d59..e21ea1f 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -227,6 +227,8 @@ struct kvm_arch_memory_slot {
};
struct kvm_arch {
+ unsigned int irq_arch;
+ int vcpus_created;
unsigned int lpid;
#ifdef CONFIG_KVM_BOOK3S_64_HV
unsigned long hpt_virt;
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 934413c..b681746 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -441,10 +441,21 @@ struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm,
unsigned int id)
{
struct kvm_vcpu *vcpu;
vcpu = kvmppc_core_vcpu_create(kvm, id);
- if (!IS_ERR(vcpu)) {
- vcpu->arch.wqp = &vcpu->wq;
- kvmppc_create_vcpu_debugfs(vcpu, id);
+ if (IS_ERR(vcpu))
+ goto out;
+
+ /* Create per-vcpu irq controller state if needed */
+ mutex_lock(&kvm->lock);
+ kvm->arch.vcpus_created = 1;
+ switch (kvm->arch.irq_arch) {
+ default:
+ break;
}
+ mutex_unlock(&kvm->lock);
+
+ vcpu->arch.wqp = &vcpu->wq;
+ kvmppc_create_vcpu_debugfs(vcpu, id);
+ out:
return vcpu;
}
@@ -459,6 +470,12 @@ void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu)
hrtimer_cancel(&vcpu->arch.dec_timer);
tasklet_kill(&vcpu->arch.tasklet);
+ /* Destroy per-vcpu irq controller state */
+ switch (vcpu->kvm->arch.irq_arch) {
+ default:
+ break;
+ }
+
kvmppc_remove_vcpu_debugfs(vcpu);
kvmppc_core_vcpu_free(vcpu);
}
@@ -996,6 +1013,49 @@ long kvm_arch_vm_ioctl(struct file *filp,
break;
}
#endif /* CONFIG_PPC_BOOK3S_64 */
+
+ case KVM_IRQ_LINE: {
+ struct kvm *kvm = filp->private_data;
+ struct kvm_irq_level args;
+
+ r = -EFAULT;
+ if (copy_from_user(&args, argp, sizeof(args)))
+ break;
+ switch (kvm->arch.irq_arch) {
+ default:
+ r = -EINVAL;
+ }
+ break;
+ }
+
+ case KVM_SET_IRQ_ARCHITECTURE: {
+ struct kvm *kvm = filp->private_data;
+ u32 arch_id;
+
+ r = -EFAULT;
+ if (get_user(arch_id, (u32 __user *)argp))
+ break;
+ r = 0;
+ switch (arch_id) {
+ case 0: /* no emulation */
+ break;
+ default:
+ r = -EINVAL;
+ break;
+ }
+ if (r)
+ break;
+
+ /* mutex ensures we don't race with vcpu creation */
+ mutex_lock(&kvm->lock);
+ if (!kvm->arch.vcpus_created)
+ kvm->arch.irq_arch = arch_id;
+ else
+ r = -EBUSY;
+ mutex_unlock(&kvm->lock);
+ break;
+ }
+
default:
r = -ENOTTY;
}
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 9a2db57..2c0ea1c 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -662,6 +662,7 @@ struct kvm_ppc_smmu_info {
#define KVM_CAP_PPC_HTAB_FD 84
#define KVM_CAP_S390_CSS_SUPPORT 85
#define KVM_CAP_PPC_EPR 86
+#define KVM_CAP_IRQ_ARCH 87
#ifdef KVM_CAP_IRQ_ROUTING
@@ -889,6 +890,8 @@ struct kvm_s390_ucas_mapping {
#define KVM_ALLOCATE_RMA _IOR(KVMIO, 0xa9, struct kvm_allocate_rma)
/* Available with KVM_CAP_PPC_HTAB_FD */
#define KVM_PPC_GET_HTAB_FD _IOW(KVMIO, 0xaa, struct kvm_get_htab_fd)
+/* Available with KVM_CAP_IRQ_ARCH */
+#define KVM_SET_IRQ_ARCHITECTURE _IOW(KVMIO, 0xab, __u32)
/*
* ioctls for vcpu fds
--
1.7.10.4
--
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