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[Qemu-devel] [PATCH v2 1/3] virtio-mmio: introduce set_host_notifier()
From: |
Pavel Fedin |
Subject: |
[Qemu-devel] [PATCH v2 1/3] virtio-mmio: introduce set_host_notifier() |
Date: |
Thu, 07 May 2015 13:48:20 +0300 |
set_host_notifier() is introduced into virtio-mmio now. Most of codes came
from virtio-pci.
Signed-off-by: Ying-Shiuan Pan <address@hidden>
Signed-off-by: Pavel Fedin <address@hidden>
---
hw/virtio/virtio-mmio.c | 72
+++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 72 insertions(+)
diff --git a/hw/virtio/virtio-mmio.c b/hw/virtio/virtio-mmio.c
index 10123f3..6b40d56 100644
--- a/hw/virtio/virtio-mmio.c
+++ b/hw/virtio/virtio-mmio.c
@@ -23,6 +23,7 @@
#include "hw/virtio/virtio.h"
#include "qemu/host-utils.h"
#include "hw/virtio/virtio-bus.h"
+#include "qemu/error-report.h"
/* #define DEBUG_VIRTIO_MMIO */
@@ -87,8 +88,59 @@ typedef struct {
uint32_t guest_page_shift;
/* virtio-bus */
VirtioBusState bus;
+ bool ioeventfd_disabled;
+ bool ioeventfd_started;
} VirtIOMMIOProxy;
+static int virtio_mmio_set_host_notifier_internal(VirtIOMMIOProxy *proxy,
+ int n, bool assign,
+ bool set_handler)
+{
+ VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
+ VirtQueue *vq = virtio_get_queue(vdev, n);
+ EventNotifier *notifier = virtio_queue_get_host_notifier(vq);
+ int r = 0;
+
+ if (assign) {
+ r = event_notifier_init(notifier, 1);
+ if (r < 0) {
+ error_report("%s: unable to init event notifier: %d",
+ __func__, r);
+ return r;
+ }
+ virtio_queue_set_host_notifier_fd_handler(vq, true, set_handler);
+ memory_region_add_eventfd(&proxy->iomem, VIRTIO_MMIO_QUEUENOTIFY,
4,
+ true, n, notifier);
+ } else {
+ memory_region_del_eventfd(&proxy->iomem, VIRTIO_MMIO_QUEUENOTIFY,
4,
+ true, n, notifier);
+ virtio_queue_set_host_notifier_fd_handler(vq, false, false);
+ event_notifier_cleanup(notifier);
+ }
+ return r;
+}
+
+static void virtio_mmio_stop_ioeventfd(VirtIOMMIOProxy *proxy)
+{
+ int r;
+ int n;
+ VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
+
+ if (!proxy->ioeventfd_started) {
+ return;
+ }
+
+ for (n = 0; n < VIRTIO_PCI_QUEUE_MAX; n++) {
+ if (!virtio_queue_get_num(vdev, n)) {
+ continue;
+ }
+
+ r = virtio_mmio_set_host_notifier_internal(proxy, n, false, false);
+ assert(r >= 0);
+ }
+ proxy->ioeventfd_started = false;
+}
+
static uint64_t virtio_mmio_read(void *opaque, hwaddr offset, unsigned
size)
{
VirtIOMMIOProxy *proxy = (VirtIOMMIOProxy *)opaque;
@@ -342,6 +394,25 @@ static void virtio_mmio_reset(DeviceState *d)
proxy->guest_page_shift = 0;
}
+static int virtio_mmio_set_host_notifier(DeviceState *opaque, int n,
+ bool assign)
+{
+ VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
+
+ /* Stop using ioeventfd for virtqueue kick if the device starts using
host
+ * notifiers. This makes it easy to avoid stepping on each others'
toes.
+ */
+ proxy->ioeventfd_disabled = assign;
+ if (assign) {
+ virtio_mmio_stop_ioeventfd(proxy);
+ }
+ /* We don't need to start here: it's not needed because backend
+ * currently only stops on status change away from ok,
+ * reset, vmstop and such. If we do add code to start here,
+ * need to check vmstate, device state etc. */
+ return virtio_mmio_set_host_notifier_internal(proxy, n, assign, false);
+}
+
/* virtio-mmio device */
/* This is called by virtio-bus just after the device is plugged. */
@@ -399,6 +470,7 @@ static void virtio_mmio_bus_class_init(ObjectClass
*klass, void *data)
k->notify = virtio_mmio_update_irq;
k->save_config = virtio_mmio_save_config;
k->load_config = virtio_mmio_load_config;
+ k->set_host_notifier = virtio_mmio_set_host_notifier;
k->get_features = virtio_mmio_get_features;
k->device_plugged = virtio_mmio_device_plugged;
k->has_variable_vring_alignment = true;
--
1.9.5.msysgit.0
Kind regards,
Pavel Fedin
Expert Engineer
Samsung Electronics Research center Russia
- [Qemu-devel] [PATCH v2 1/3] virtio-mmio: introduce set_host_notifier(),
Pavel Fedin <=