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authorJan Kiszka <jan.kiszka@siemens.com>2012-03-29 21:14:12 +0200
committerAvi Kivity <avi@redhat.com>2012-04-24 15:59:47 +0300
commit07975ad3b30579ca27d880491ad992326b930c63 (patch)
treefea166a02c387949a09a948a51781074bdc9ed68 /virt
parent1f15d10984c854e077da5aa1a23f901496b49773 (diff)
downloadlinux-07975ad3b30579ca27d880491ad992326b930c63.tar.gz
KVM: Introduce direct MSI message injection for in-kernel irqchips
Currently, MSI messages can only be injected to in-kernel irqchips by defining a corresponding IRQ route for each message. This is not only unhandy if the MSI messages are generated "on the fly" by user space, IRQ routes are a limited resource that user space has to manage carefully. By providing a direct injection path, we can both avoid using up limited resources and simplify the necessary steps for user land. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'virt')
-rw-r--r--virt/kvm/Kconfig3
-rw-r--r--virt/kvm/irq_comm.c14
-rw-r--r--virt/kvm/kvm_main.c14
3 files changed, 31 insertions, 0 deletions
diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig
index f63ccb0a598..28694f4a913 100644
--- a/virt/kvm/Kconfig
+++ b/virt/kvm/Kconfig
@@ -18,3 +18,6 @@ config KVM_MMIO
config KVM_ASYNC_PF
bool
+
+config HAVE_KVM_MSI
+ bool
diff --git a/virt/kvm/irq_comm.c b/virt/kvm/irq_comm.c
index 9f614b4e365..a6a0365475e 100644
--- a/virt/kvm/irq_comm.c
+++ b/virt/kvm/irq_comm.c
@@ -138,6 +138,20 @@ int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
return kvm_irq_delivery_to_apic(kvm, NULL, &irq);
}
+int kvm_send_userspace_msi(struct kvm *kvm, struct kvm_msi *msi)
+{
+ struct kvm_kernel_irq_routing_entry route;
+
+ if (!irqchip_in_kernel(kvm) || msi->flags != 0)
+ return -EINVAL;
+
+ route.msi.address_lo = msi->address_lo;
+ route.msi.address_hi = msi->address_hi;
+ route.msi.data = msi->data;
+
+ return kvm_set_msi(&route, kvm, KVM_USERSPACE_IRQ_SOURCE_ID, 1);
+}
+
/*
* Return value:
* < 0 Interrupt was ignored (masked or not delivered for other reasons)
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 9eb7936e491..1847c762d8d 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2060,6 +2060,17 @@ static long kvm_vm_ioctl(struct file *filp,
mutex_unlock(&kvm->lock);
break;
#endif
+#ifdef CONFIG_HAVE_KVM_MSI
+ case KVM_SIGNAL_MSI: {
+ struct kvm_msi msi;
+
+ r = -EFAULT;
+ if (copy_from_user(&msi, argp, sizeof msi))
+ goto out;
+ r = kvm_send_userspace_msi(kvm, &msi);
+ break;
+ }
+#endif
default:
r = kvm_arch_vm_ioctl(filp, ioctl, arg);
if (r == -ENOTTY)
@@ -2188,6 +2199,9 @@ static long kvm_dev_ioctl_check_extension_generic(long arg)
case KVM_CAP_SET_BOOT_CPU_ID:
#endif
case KVM_CAP_INTERNAL_ERROR_DATA:
+#ifdef CONFIG_HAVE_KVM_MSI
+ case KVM_CAP_SIGNAL_MSI:
+#endif
return 1;
#ifdef CONFIG_HAVE_KVM_IRQCHIP
case KVM_CAP_IRQ_ROUTING: