* [Qemu-devel] [PATCH 0/3] Introduce virtqueue_get_avail_bytes()
@ 2012-07-06 10:37 Amit Shah
2012-07-06 10:37 ` [Qemu-devel] [PATCH 1/3] virtio: use unsigned int for counting bytes in vq Amit Shah
` (4 more replies)
0 siblings, 5 replies; 6+ messages in thread
From: Amit Shah @ 2012-07-06 10:37 UTC (permalink / raw)
To: qemu list; +Cc: Amit Shah, Anthony Liguori
The current virtqueue_avail_bytes() is a weird API: it's oddly-named:
doesn't tell us what the API is going to do, and also suits just one
use-case (that in virtio-net.c).
Introduce virtqueue_get_avail_bytes(), which returns the number of
bytes in the vq available for input as well as output.
virtqueue_avail_bytes() is made a wrapper around this new function for
now. It should be deprecated soon, though.
Doing this will also help with the virtio-rng patch where a
VirtQueueElement is popped only to find out what its size is. With
this series applied, the popping (and the subsequent save/load of
state for migration) isn't necessary.
The virtio-serial-bus code becomes better too, that's patch 3 here.
Please apply,
Amit Shah (3):
virtio: use unsigned int for counting bytes in vq
virtio: Introduce virtqueue_get_avail_bytes()
virtio-serial-bus: let chardev know the exact number of bytes
requested
hw/virtio-serial-bus.c | 11 +++--------
hw/virtio.c | 30 ++++++++++++++++++++++--------
hw/virtio.h | 5 ++++-
3 files changed, 29 insertions(+), 17 deletions(-)
--
1.7.7.6
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Qemu-devel] [PATCH 1/3] virtio: use unsigned int for counting bytes in vq
2012-07-06 10:37 [Qemu-devel] [PATCH 0/3] Introduce virtqueue_get_avail_bytes() Amit Shah
@ 2012-07-06 10:37 ` Amit Shah
2012-07-06 10:37 ` [Qemu-devel] [PATCH 2/3] virtio: Introduce virtqueue_get_avail_bytes() Amit Shah
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Amit Shah @ 2012-07-06 10:37 UTC (permalink / raw)
To: qemu list; +Cc: Amit Shah, Anthony Liguori
The virtqueue_avail_bytes() function counts bytes in an int. Use an
unsigned int instead.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
---
hw/virtio.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/hw/virtio.c b/hw/virtio.c
index 168abe4..b21dcac 100644
--- a/hw/virtio.c
+++ b/hw/virtio.c
@@ -338,7 +338,7 @@ static unsigned virtqueue_next_desc(target_phys_addr_t desc_pa,
int virtqueue_avail_bytes(VirtQueue *vq, int in_bytes, int out_bytes)
{
unsigned int idx;
- int total_bufs, in_total, out_total;
+ unsigned int total_bufs, in_total, out_total;
idx = vq->last_avail_idx;
--
1.7.7.6
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [Qemu-devel] [PATCH 2/3] virtio: Introduce virtqueue_get_avail_bytes()
2012-07-06 10:37 [Qemu-devel] [PATCH 0/3] Introduce virtqueue_get_avail_bytes() Amit Shah
2012-07-06 10:37 ` [Qemu-devel] [PATCH 1/3] virtio: use unsigned int for counting bytes in vq Amit Shah
@ 2012-07-06 10:37 ` Amit Shah
2012-07-06 10:37 ` [Qemu-devel] [PATCH 3/3] virtio-serial-bus: let chardev know the exact number of bytes requested Amit Shah
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Amit Shah @ 2012-07-06 10:37 UTC (permalink / raw)
To: qemu list; +Cc: Amit Shah, Anthony Liguori
The current virtqueue_avail_bytes() is oddly named, and checks if a
particular number of bytes are available in a vq. A better API is to
fetch the number of bytes available in the vq, and let the caller do
what's interesting with the numbers.
Introduce virtqueue_get_avail_bytes(), which returns the number of bytes
for buffers marked for both, in as well as out. virtqueue_avail_bytes()
is made a wrapper over this new function.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
---
hw/virtio.c | 28 +++++++++++++++++++++-------
hw/virtio.h | 5 ++++-
2 files changed, 25 insertions(+), 8 deletions(-)
diff --git a/hw/virtio.c b/hw/virtio.c
index b21dcac..40ca6b5 100644
--- a/hw/virtio.c
+++ b/hw/virtio.c
@@ -335,7 +335,8 @@ static unsigned virtqueue_next_desc(target_phys_addr_t desc_pa,
return next;
}
-int virtqueue_avail_bytes(VirtQueue *vq, int in_bytes, int out_bytes)
+void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes,
+ unsigned int *out_bytes)
{
unsigned int idx;
unsigned int total_bufs, in_total, out_total;
@@ -380,13 +381,9 @@ int virtqueue_avail_bytes(VirtQueue *vq, int in_bytes, int out_bytes)
}
if (vring_desc_flags(desc_pa, i) & VRING_DESC_F_WRITE) {
- if (in_bytes > 0 &&
- (in_total += vring_desc_len(desc_pa, i)) >= in_bytes)
- return 1;
+ in_total += vring_desc_len(desc_pa, i);
} else {
- if (out_bytes > 0 &&
- (out_total += vring_desc_len(desc_pa, i)) >= out_bytes)
- return 1;
+ out_total += vring_desc_len(desc_pa, i);
}
} while ((i = virtqueue_next_desc(desc_pa, i, max)) != max);
@@ -395,7 +392,24 @@ int virtqueue_avail_bytes(VirtQueue *vq, int in_bytes, int out_bytes)
else
total_bufs++;
}
+ if (in_bytes) {
+ *in_bytes = in_total;
+ }
+ if (out_bytes) {
+ *out_bytes = out_total;
+ }
+}
+int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes,
+ unsigned int out_bytes)
+{
+ unsigned int in_total, out_total;
+
+ virtqueue_get_avail_bytes(vq, &in_total, &out_total);
+ if ((in_bytes && in_bytes < in_total)
+ || (out_bytes && out_bytes < out_total)) {
+ return 1;
+ }
return 0;
}
diff --git a/hw/virtio.h b/hw/virtio.h
index 85aabe5..54d5bbf 100644
--- a/hw/virtio.h
+++ b/hw/virtio.h
@@ -148,7 +148,10 @@ void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem,
void virtqueue_map_sg(struct iovec *sg, target_phys_addr_t *addr,
size_t num_sg, int is_write);
int virtqueue_pop(VirtQueue *vq, VirtQueueElement *elem);
-int virtqueue_avail_bytes(VirtQueue *vq, int in_bytes, int out_bytes);
+int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes,
+ unsigned int out_bytes);
+void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes,
+ unsigned int *out_bytes);
void virtio_notify(VirtIODevice *vdev, VirtQueue *vq);
--
1.7.7.6
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [Qemu-devel] [PATCH 3/3] virtio-serial-bus: let chardev know the exact number of bytes requested
2012-07-06 10:37 [Qemu-devel] [PATCH 0/3] Introduce virtqueue_get_avail_bytes() Amit Shah
2012-07-06 10:37 ` [Qemu-devel] [PATCH 1/3] virtio: use unsigned int for counting bytes in vq Amit Shah
2012-07-06 10:37 ` [Qemu-devel] [PATCH 2/3] virtio: Introduce virtqueue_get_avail_bytes() Amit Shah
@ 2012-07-06 10:37 ` Amit Shah
2012-07-16 12:58 ` [Qemu-devel] [PATCH 0/3] Introduce virtqueue_get_avail_bytes() Amit Shah
2012-07-26 14:27 ` Amit Shah
4 siblings, 0 replies; 6+ messages in thread
From: Amit Shah @ 2012-07-06 10:37 UTC (permalink / raw)
To: qemu list; +Cc: Amit Shah, Anthony Liguori
Using the virtqueue_avail_bytes() function had an unnecessarily
crippling effect on the number of bytes needed by the guest as reported
to the chardev layer in the can_read() callback.
Using the new virtqueue_get_avail_bytes() function will let us advertise
the exact number of bytes we can send to the guest.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
---
hw/virtio-serial-bus.c | 11 +++--------
1 files changed, 3 insertions(+), 8 deletions(-)
diff --git a/hw/virtio-serial-bus.c b/hw/virtio-serial-bus.c
index 96382a4..44d5862 100644
--- a/hw/virtio-serial-bus.c
+++ b/hw/virtio-serial-bus.c
@@ -287,6 +287,7 @@ ssize_t virtio_serial_write(VirtIOSerialPort *port, const uint8_t *buf,
size_t virtio_serial_guest_ready(VirtIOSerialPort *port)
{
VirtQueue *vq = port->ivq;
+ unsigned int bytes;
if (!virtio_queue_ready(vq) ||
!(port->vser->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK) ||
@@ -296,14 +297,8 @@ size_t virtio_serial_guest_ready(VirtIOSerialPort *port)
if (use_multiport(port->vser) && !port->guest_connected) {
return 0;
}
-
- if (virtqueue_avail_bytes(vq, 4096, 0)) {
- return 4096;
- }
- if (virtqueue_avail_bytes(vq, 1, 0)) {
- return 1;
- }
- return 0;
+ virtqueue_get_avail_bytes(vq, &bytes, NULL);
+ return bytes;
}
static void flush_queued_data_bh(void *opaque)
--
1.7.7.6
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] [PATCH 0/3] Introduce virtqueue_get_avail_bytes()
2012-07-06 10:37 [Qemu-devel] [PATCH 0/3] Introduce virtqueue_get_avail_bytes() Amit Shah
` (2 preceding siblings ...)
2012-07-06 10:37 ` [Qemu-devel] [PATCH 3/3] virtio-serial-bus: let chardev know the exact number of bytes requested Amit Shah
@ 2012-07-16 12:58 ` Amit Shah
2012-07-26 14:27 ` Amit Shah
4 siblings, 0 replies; 6+ messages in thread
From: Amit Shah @ 2012-07-16 12:58 UTC (permalink / raw)
To: qemu list; +Cc: Anthony Liguori
On (Fri) 06 Jul 2012 [16:07:06], Amit Shah wrote:
> The current virtqueue_avail_bytes() is a weird API: it's oddly-named:
> doesn't tell us what the API is going to do, and also suits just one
> use-case (that in virtio-net.c).
>
> Introduce virtqueue_get_avail_bytes(), which returns the number of
> bytes in the vq available for input as well as output.
> virtqueue_avail_bytes() is made a wrapper around this new function for
> now. It should be deprecated soon, though.
>
> Doing this will also help with the virtio-rng patch where a
> VirtQueueElement is popped only to find out what its size is. With
> this series applied, the popping (and the subsequent save/load of
> state for migration) isn't necessary.
>
> The virtio-serial-bus code becomes better too, that's patch 3 here.
Ping?
Amit
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] [PATCH 0/3] Introduce virtqueue_get_avail_bytes()
2012-07-06 10:37 [Qemu-devel] [PATCH 0/3] Introduce virtqueue_get_avail_bytes() Amit Shah
` (3 preceding siblings ...)
2012-07-16 12:58 ` [Qemu-devel] [PATCH 0/3] Introduce virtqueue_get_avail_bytes() Amit Shah
@ 2012-07-26 14:27 ` Amit Shah
4 siblings, 0 replies; 6+ messages in thread
From: Amit Shah @ 2012-07-26 14:27 UTC (permalink / raw)
To: qemu list; +Cc: Anthony Liguori
On (Fri) 06 Jul 2012 [16:07:06], Amit Shah wrote:
> The current virtqueue_avail_bytes() is a weird API: it's oddly-named:
> doesn't tell us what the API is going to do, and also suits just one
> use-case (that in virtio-net.c).
>
> Introduce virtqueue_get_avail_bytes(), which returns the number of
> bytes in the vq available for input as well as output.
> virtqueue_avail_bytes() is made a wrapper around this new function for
> now. It should be deprecated soon, though.
>
> Doing this will also help with the virtio-rng patch where a
> VirtQueueElement is popped only to find out what its size is. With
> this series applied, the popping (and the subsequent save/load of
> state for migration) isn't necessary.
>
> The virtio-serial-bus code becomes better too, that's patch 3 here.
>
> Please apply,
Ping again.
Amit
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2012-07-26 14:27 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2012-07-06 10:37 [Qemu-devel] [PATCH 0/3] Introduce virtqueue_get_avail_bytes() Amit Shah
2012-07-06 10:37 ` [Qemu-devel] [PATCH 1/3] virtio: use unsigned int for counting bytes in vq Amit Shah
2012-07-06 10:37 ` [Qemu-devel] [PATCH 2/3] virtio: Introduce virtqueue_get_avail_bytes() Amit Shah
2012-07-06 10:37 ` [Qemu-devel] [PATCH 3/3] virtio-serial-bus: let chardev know the exact number of bytes requested Amit Shah
2012-07-16 12:58 ` [Qemu-devel] [PATCH 0/3] Introduce virtqueue_get_avail_bytes() Amit Shah
2012-07-26 14:27 ` Amit Shah
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.