diff options
authorAndre Przywara <andre.przywara@arm.com>2016-07-15 12:43:26 +0100
committerMarc Zyngier <marc.zyngier@arm.com>2016-07-18 18:10:40 +0100
commit8a39d00670f0792c1186e442e1dd28fe0326f2ee (patch)
parentb46f01ce4dcfdce636588fe2ef5035724c77f266 (diff)
KVM: kvm_io_bus: Add kvm_io_bus_get_dev() call
The kvm_io_bus framework is a nice place of holding information about various MMIO regions for kernel emulated devices. Add a call to retrieve the kvm_io_device structure which is associated with a certain MMIO address. This avoids to duplicate kvm_io_bus' knowledge of MMIO regions without having to fake MMIO calls if a user needs the device a certain MMIO address belongs to. This will be used by the ITS emulation to get the associated ITS device when someone triggers an MSI via an ioctl from userspace. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Tested-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2 files changed, 26 insertions, 0 deletions
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 0640ee92b978..614a98137c5f 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -164,6 +164,8 @@ int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
int len, struct kvm_io_device *dev);
int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,
struct kvm_io_device *dev);
+struct kvm_io_device *kvm_io_bus_get_dev(struct kvm *kvm, enum kvm_bus bus_idx,
+ gpa_t addr);
struct kvm_async_pf {
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index ef54b4c31792..bd2eb92c5d0e 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -3496,6 +3496,30 @@ int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,
return r;
+struct kvm_io_device *kvm_io_bus_get_dev(struct kvm *kvm, enum kvm_bus bus_idx,
+ gpa_t addr)
+ struct kvm_io_bus *bus;
+ int dev_idx, srcu_idx;
+ struct kvm_io_device *iodev = NULL;
+ srcu_idx = srcu_read_lock(&kvm->srcu);
+ bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu);
+ dev_idx = kvm_io_bus_get_first_dev(bus, addr, 1);
+ if (dev_idx < 0)
+ goto out_unlock;
+ iodev = bus->range[dev_idx].dev;
+ srcu_read_unlock(&kvm->srcu, srcu_idx);
+ return iodev;
static struct notifier_block kvm_cpu_notifier = {
.notifier_call = kvm_cpu_hotplug,