diff mbox

[1/4] virtio-mmio: introduce set_host_notifier()

Message ID 000601d087d1$8d095ca0$a71c15e0$@samsung.com
State New
Headers show

Commit Message

Pavel Fedin May 6, 2015, 7:52 a.m. UTC 
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 <p.fedin@samsung.com>
---
 hw/virtio/virtio-mmio.c | 70
+++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 70 insertions(+)

 static uint64_t virtio_mmio_read(void *opaque, hwaddr offset, unsigned
size)
 {
     VirtIOMMIOProxy *proxy = (VirtIOMMIOProxy *)opaque;
@@ -342,6 +393,24 @@ 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 +468,7 @@ 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;

Comments

Eric Blake May 6, 2015, 2:52 p.m. UTC | #1 
On 05/06/2015 01:52 AM, Pavel Fedin wrote:

[meta-comment]

> set_host_notifier() is introduced into virtio-mmio now. Most of codes came
> from virtio-pci.
> 

Missing an 'In-Reply-To: <000501d087d0$39c1bd90$ad4538b0$@samsung.com>'
header, which makes your series unthreaded (every message appeared as
its own thread).  It makes review easier if everything is properly
threaded to the cover letter, so you may want to send a series to
yourself first as a test case of your setup before sending to the list.

Other submission hints at: http://wiki.qemu.org/Contribute/SubmitAPatch

>  
> +static int virtio_mmio_set_host_notifier_internal(VirtIOMMIOProxy *proxy,
> +                                                  int n, bool assign, bool
> set_handler)

Long line, you might want to wrap it to fit in 80 columns.
diff mbox

Patch

diff --git a/hw/virtio/virtio-mmio.c b/hw/virtio/virtio-mmio.c
index 10123f3..32bf240 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 +88,58 @@  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;
+}
+