Patchwork [PATCHv2,08/12] virtio-pci: fill in notifier support

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Submitter Michael S. Tsirkin
Date Feb. 25, 2010, 6:28 p.m.
Message ID <70c29d6d75bc3ee2efc89f5c3f8be833d660a1be.1267122331.git.mst@redhat.com>
Download mbox | patch
Permalink /patch/46268/
State New
Headers show

Comments

Michael S. Tsirkin - Feb. 25, 2010, 6:28 p.m.
Support host/guest notifiers in virtio-pci.
The last one only with kvm, that's okay
because vhost relies on kvm anyway.

Note on kvm usage: kvm ioeventfd API
is implemented on non-kvm systems as well,
this is the reason we don't need if (kvm_enabled())
around it.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/virtio-pci.c |   62 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 62 insertions(+), 0 deletions(-)
Anthony Liguori - Feb. 25, 2010, 7:30 p.m.
On 02/25/2010 12:28 PM, Michael S. Tsirkin wrote:
> Support host/guest notifiers in virtio-pci.
> The last one only with kvm, that's okay
> because vhost relies on kvm anyway.
>
> Note on kvm usage: kvm ioeventfd API
> is implemented on non-kvm systems as well,
> this is the reason we don't need if (kvm_enabled())
> around it.
>
> Signed-off-by: Michael S. Tsirkin<mst@redhat.com>
> ---
>   hw/virtio-pci.c |   62 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
>   1 files changed, 62 insertions(+), 0 deletions(-)
>
> diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c
> index 006ff38..3f1214c 100644
> --- a/hw/virtio-pci.c
> +++ b/hw/virtio-pci.c
> @@ -24,6 +24,7 @@
>   #include "net.h"
>   #include "block_int.h"
>   #include "loader.h"
> +#include "kvm.h"
>
>   /* from Linux's linux/virtio_pci.h */
>
> @@ -398,6 +399,65 @@ static unsigned virtio_pci_get_features(void *opaque)
>       return proxy->host_features;
>   }
>
> +static void virtio_pci_guest_notifier_read(void *opaque)
> +{
> +    VirtQueue *vq = opaque;
> +    EventNotifier *n = virtio_queue_guest_notifier(vq);
> +    if (event_notifier_test_and_clear(n)) {
> +        virtio_irq(vq);
> +    }
> +}
> +
> +static int virtio_pci_guest_notifier(void *opaque, int n, bool assign)
> +{
> +    VirtIOPCIProxy *proxy = opaque;
> +    VirtQueue *vq = virtio_queue(proxy->vdev, n);
> +    EventNotifier *notifier = virtio_queue_guest_notifier(vq);
> +
> +    if (assign) {
> +        int r = event_notifier_init(notifier, 0);
> +	if (r<  0)
> +		return r;
> +        qemu_set_fd_handler(event_notifier_get_fd(notifier),
> +                            virtio_pci_guest_notifier_read, NULL, vq);
>    

While not super important, it would be nice to have this a bit more 
common.  IOW:

     r = read_event_notifier_init(notifier, 
virtio_pci_guest_notifier_read, vq);

and:

     r = kvm_eventfd_notifier_init(notifier, proxy->addr + 
VIRTIO_PCI_QUEUE_NOTIFY, n, assign);

Regards,

Anthony Liguori
Michael S. Tsirkin - Feb. 28, 2010, 8:02 p.m.
On Thu, Feb 25, 2010 at 01:30:40PM -0600, Anthony Liguori wrote:
> On 02/25/2010 12:28 PM, Michael S. Tsirkin wrote:
>> Support host/guest notifiers in virtio-pci.
>> The last one only with kvm, that's okay
>> because vhost relies on kvm anyway.
>>
>> Note on kvm usage: kvm ioeventfd API
>> is implemented on non-kvm systems as well,
>> this is the reason we don't need if (kvm_enabled())
>> around it.
>>
>> Signed-off-by: Michael S. Tsirkin<mst@redhat.com>
>> ---
>>   hw/virtio-pci.c |   62 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
>>   1 files changed, 62 insertions(+), 0 deletions(-)
>>
>> diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c
>> index 006ff38..3f1214c 100644
>> --- a/hw/virtio-pci.c
>> +++ b/hw/virtio-pci.c
>> @@ -24,6 +24,7 @@
>>   #include "net.h"
>>   #include "block_int.h"
>>   #include "loader.h"
>> +#include "kvm.h"
>>
>>   /* from Linux's linux/virtio_pci.h */
>>
>> @@ -398,6 +399,65 @@ static unsigned virtio_pci_get_features(void *opaque)
>>       return proxy->host_features;
>>   }
>>
>> +static void virtio_pci_guest_notifier_read(void *opaque)
>> +{
>> +    VirtQueue *vq = opaque;
>> +    EventNotifier *n = virtio_queue_guest_notifier(vq);
>> +    if (event_notifier_test_and_clear(n)) {
>> +        virtio_irq(vq);
>> +    }
>> +}
>> +
>> +static int virtio_pci_guest_notifier(void *opaque, int n, bool assign)
>> +{
>> +    VirtIOPCIProxy *proxy = opaque;
>> +    VirtQueue *vq = virtio_queue(proxy->vdev, n);
>> +    EventNotifier *notifier = virtio_queue_guest_notifier(vq);
>> +
>> +    if (assign) {
>> +        int r = event_notifier_init(notifier, 0);
>> +	if (r<  0)
>> +		return r;
>> +        qemu_set_fd_handler(event_notifier_get_fd(notifier),
>> +                            virtio_pci_guest_notifier_read, NULL, vq);
>>    
>
> While not super important, it would be nice to have this a bit more  
> common.  IOW:
>
>     r = read_event_notifier_init(notifier,  
> virtio_pci_guest_notifier_read, vq);
>
> and:
>
>     r = kvm_eventfd_notifier_init(notifier, proxy->addr +  
> VIRTIO_PCI_QUEUE_NOTIFY, n, assign);
>
> Regards,
>
> Anthony Liguori


Hmm. Note that on qemu-kvm we also have interrupts using notifiers.
Possibly it's best to merge this, merge irqchip from qemu-kvm,
then think about the best API.

Patch

diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c
index 006ff38..3f1214c 100644
--- a/hw/virtio-pci.c
+++ b/hw/virtio-pci.c
@@ -24,6 +24,7 @@ 
 #include "net.h"
 #include "block_int.h"
 #include "loader.h"
+#include "kvm.h"
 
 /* from Linux's linux/virtio_pci.h */
 
@@ -398,6 +399,65 @@  static unsigned virtio_pci_get_features(void *opaque)
     return proxy->host_features;
 }
 
+static void virtio_pci_guest_notifier_read(void *opaque)
+{
+    VirtQueue *vq = opaque;
+    EventNotifier *n = virtio_queue_guest_notifier(vq);
+    if (event_notifier_test_and_clear(n)) {
+        virtio_irq(vq);
+    }
+}
+
+static int virtio_pci_guest_notifier(void *opaque, int n, bool assign)
+{
+    VirtIOPCIProxy *proxy = opaque;
+    VirtQueue *vq = virtio_queue(proxy->vdev, n);
+    EventNotifier *notifier = virtio_queue_guest_notifier(vq);
+
+    if (assign) {
+        int r = event_notifier_init(notifier, 0);
+	if (r < 0)
+		return r;
+        qemu_set_fd_handler(event_notifier_get_fd(notifier),
+                            virtio_pci_guest_notifier_read, NULL, vq);
+    } else {
+        qemu_set_fd_handler(event_notifier_get_fd(notifier),
+                            NULL, NULL, NULL);
+        event_notifier_cleanup(notifier);
+    }
+
+    return 0;
+}
+
+static int virtio_pci_host_notifier(void *opaque, int n, bool assign)
+{
+    VirtIOPCIProxy *proxy = opaque;
+    VirtQueue *vq = virtio_queue(proxy->vdev, n);
+    EventNotifier *notifier = virtio_queue_host_notifier(vq);
+    int r;
+    if (assign) {
+        r = event_notifier_init(notifier, 1);
+        if (r < 0) {
+            return r;
+        }
+        r = kvm_set_ioeventfd(proxy->addr + VIRTIO_PCI_QUEUE_NOTIFY,
+                              n, event_notifier_get_fd(notifier),
+                              assign);
+        if (r < 0) {
+            event_notifier_cleanup(notifier);
+        }
+    } else {
+        r = kvm_set_ioeventfd(proxy->addr + VIRTIO_PCI_QUEUE_NOTIFY,
+                              n, event_notifier_get_fd(notifier),
+                              assign);
+        if (r < 0) {
+            return r;
+        }
+        event_notifier_cleanup(notifier);
+    }
+    return r;
+}
+
 static const VirtIOBindings virtio_pci_bindings = {
     .notify = virtio_pci_notify,
     .save_config = virtio_pci_save_config,
@@ -405,6 +465,8 @@  static const VirtIOBindings virtio_pci_bindings = {
     .save_queue = virtio_pci_save_queue,
     .load_queue = virtio_pci_load_queue,
     .get_features = virtio_pci_get_features,
+    .host_notifier = virtio_pci_host_notifier,
+    .guest_notifier = virtio_pci_guest_notifier,
 };
 
 static void virtio_init_pci(VirtIOPCIProxy *proxy, VirtIODevice *vdev,