On 01/09/14 15:29, Paolo Bonzini wrote: > Il 01/09/2014 15:22, Christian Borntraeger ha scritto: >>>> If virtio-blk and virtio-serial share an IRQ, the guest operating system has to check each virtqueue for activity. Maybe there is some inefficiency doing that. >>>> AFAIK virtio-serial registers 64 virtqueues (on 31 ports + console) even if everything is unused. >>> >>> That could be the case if MSI is disabled. >> >> Do the windows virtio drivers enable MSIs, in their inf file? > > It depends on the version of the drivers, but it is a reasonable guess > at what differs between Linux and Windows. Haoyu, can you give us the > output of lspci from a Linux guest? > > Paolo Zhang Haoyu, which virtio drivers did you use? I just checked the Fedora virtio driver. The INF file does not contain the MSI enablement as described in http://msdn.microsoft.com/en-us/library/windows/hardware/ff544246%28v=vs.85%29.aspx That would explain the performance issues - given that the link information is still true. Christian -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
