On Tue, Apr 07, 2015 at 08:06:14PM +0200, Luigi Rizzo wrote: > > > On Tue, Apr 7, 2015 at 6:54 PM, Alexander Graf <ag...@suse.de> wrote: > > On 04/01/2015 10:15 AM, Jason Wang 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. > ... > > * configuration space */ > #define VIRTIO_PCI_CONFIG_SIZE(dev) VIRTIO_PCI_CONFIG_OFF > (msix_enabled(dev)) > -#define VIRTIO_PCI_QUEUE_MAX 64 > +#define VIRTIO_PCI_QUEUE_MAX 513 > > > 513 is an interesting number. Any particular reason for it? Maybe this was > mentioned before and I just missed it ;) > > > > quite large, too. I thought multiple queue pairs were useful > to split the load for multicore machines, but targeting VMs with > up to 256 cores (and presumably an equal number in the host) > seems really forward looking.
Well, that's the # of VCPUs QEMU supports ATM, no? Seems silly to have limit on vqs block us from creating such VMs. Maybe just define it as max cpus * 2 + 1. > On the other hand, the message is dated april first... > cheers > luigi
