[PATCH v8 05/17] KVM: kvm_io_bus: add kvm_io_bus_get_dev() call
From: Christoffer Dall <hidden>
Date: 2016-07-06 21:15:18
Also in:
kvm, kvmarm
On Tue, Jul 05, 2016 at 12:22:57PM +0100, Andre Przywara wrote:
quoted hunk ↗ jump to hunk
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> --- include/linux/kvm_host.h | 2 ++ virt/kvm/kvm_main.c | 24 ++++++++++++++++++++++++ 2 files changed, 26 insertions(+)diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 0640ee9..614a981 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); #ifdef CONFIG_KVM_ASYNC_PF struct kvm_async_pf {diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index ef54b4c..bd2eb92 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; }
do you need to hold kvm->slots_lock here like the other functions touching the io_bus framework here, which have comments specifying that?
+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;
+
+out_unlock:
+ srcu_read_unlock(&kvm->srcu, srcu_idx);
+
+ return iodev;
+}
+EXPORT_SYMBOL_GPL(kvm_io_bus_get_dev);
+
static struct notifier_block kvm_cpu_notifier = {
.notifier_call = kvm_cpu_hotplug,
};
--
2.9.0You also need an ack here, but my comment-comment above notwithstanding: Acked-by: Christoffer Dall <redacted> -Christoffer