On Thu, 23 Apr 2015 14:21:48 +0800
Jason Wang <address@hidden> wrote:
This patch increases the maximum number of virtqueues for pci from
64
to 513. This will allow booting a virtio-net-pci device with 256
queue
^^^
pairs on recent Linux host (which supports up to 256 tuntap queue
pairs).
To keep migration compatibility, 64 was kept for legacy machine
types. This is because qemu in fact allows guest to probe the limit
of
virtqueues through trying to set queue_sel. So for legacy machine
type, we should make sure setting queue_sel to more than 63 won't
make effect.
Cc: Paolo Bonzini <address@hidden>
Cc: Richard Henderson <address@hidden>
Cc: Michael S. Tsirkin <address@hidden>
Cc: Alexander Graf <address@hidden>
Cc: address@hidden
Signed-off-by: Jason Wang <address@hidden>
---
hw/i386/pc_piix.c | 5 +++++
hw/i386/pc_q35.c | 5 +++++
hw/ppc/spapr.c | 5 +++++
hw/virtio/virtio-pci.c | 6 +++++-
4 files changed, 20 insertions(+), 1 deletion(-)
(...)
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index 7d01500..c510cb7 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -42,7 +42,11 @@
* configuration space */
#define VIRTIO_PCI_CONFIG_SIZE(dev)
VIRTIO_PCI_CONFIG_OFF(msix_enabled(dev))
-#define VIRTIO_PCI_QUEUE_MAX 64
+/* The number was chose to be greater than both the the number of
max
+ * vcpus supported by host and the number of max tuntap queues
support
+ * by host and also leave some spaces for future.
+ */
+#define VIRTIO_PCI_QUEUE_MAX 1024
^^^^
I think you need to fixup subject and patch description :)