We current limit the max virtio queues to 64. This is not sufficient to support some multiqueue deivces (e.g recent Linux support up to 256 tap queues). So this series try to let virtio to support more queues.
No much works needs to be done except: - Patch 1 add a check to validate the queues supported by backend against the virtio queue limitation - Patch 2 fixes a bug in virtio_del_queue() - Patch 3 introdues a bus specific queue limitation - Patch 4 - Patch 8 let each transport to use bus specific queue limitation instead of VIRTIO_PCI_QUEUE_MAX - Patch 9 increase the maximum number of queues supported by virtio-pci from 64 to 513, and deal with the migration compatibility with the changes. - Patch 10 tries to remove the hard coded MSI-X bar size (4096) and allow up to 2048 MSI-X entries. - Patch 11 add a boolean property to let the virtio-net can calculate the MSI-X bar size based on the number of MSI-X vectors and keep migration compatibility with legacy version whose bar size is 4096. With this patch, we can support up to 256 queues. Since x86 can only allow about 240 interrupt vectors for MSI-X, current Linux driver can only have about 80 queue pairs has their private MSI-X interrupt vectors. With sharing IRQ with queue pairs (RFC posted in https://lkml.org/lkml/2014/12/25/169), Linux driver can have up to about 186 queue pairs has their private MSI-X interrupt vectors. Stress/migration test on virtio-pci, compile test/make check on other s390-softmmu. Cc: Paolo Bonzini <pbonz...@redhat.com> Cc: Richard Henderson <r...@twiddle.net> Cc: Anthony Liguori <aligu...@amazon.com> Cc: Michael S. Tsirkin <m...@redhat.com> Cc: Alexander Graf <ag...@suse.de> Cc: Keith Busch <keith.bu...@intel.com> Cc: Kevin Wolf <kw...@redhat.com> Cc: Stefan Hajnoczi <stefa...@redhat.com> Cc: Anthony Liguori <aligu...@amazon.com> Cc: Christian Borntraeger <borntrae...@de.ibm.com> Cc: Cornelia Huck <cornelia.h...@de.ibm.com> Cc: Amit Shah <amit.s...@redhat.com> Please review Thanks Changes from V1: - add a validation against the bus limitation - switch to use a bus specific queue limit instead of a global one, this will allow us to just increase the limit of one transport without disturbing others. - only increase the queue limit of virtio-pci - limit the maximum number of virtio queues to 64 for legacy machine types Jason Wang (11): virtio-net: validate backend queue numbers against bus limitation virtio-net: fix the upper bound when trying to delete queues virito: introduce bus specific queue limit virtio-ccw: introduce ccw specific queue limit virtio-serial-bus: switch to bus specific queue limit virtio-s390: switch to bus specific queue limit virtio-mmio: switch to bus specific queue limit virtio-pci: switch to use bus specific queue limit virtio-pci: increase the maximum number of virtqueues to 513 pci: remove hard-coded bar size in msix_init_exclusive_bar() virtio-pci: introduce auto_msix_bar_size property hw/block/nvme.c | 2 +- hw/char/virtio-serial-bus.c | 4 +++- hw/i386/pc_piix.c | 10 ++++++++ hw/i386/pc_q35.c | 9 ++++++++ hw/misc/ivshmem.c | 2 +- hw/net/virtio-net.c | 9 +++++++- hw/pci/msix.c | 18 ++++++--------- hw/ppc/spapr.c | 5 ++++ hw/s390x/s390-virtio-bus.c | 5 ++-- hw/s390x/s390-virtio-ccw.c | 7 ++++-- hw/s390x/virtio-ccw.c | 12 ++++++---- hw/scsi/virtio-scsi.c | 4 ++-- hw/virtio/virtio-mmio.c | 5 ++-- hw/virtio/virtio-pci.c | 28 +++++++++++++++++------ hw/virtio/virtio-pci.h | 3 +++ hw/virtio/virtio.c | 52 +++++++++++++++++++++++++++++++----------- include/hw/compat.h | 8 +++++++ include/hw/pci/msix.h | 2 +- include/hw/s390x/s390_flic.h | 2 +- include/hw/virtio/virtio-bus.h | 1 + include/hw/virtio/virtio.h | 6 ++++- 21 files changed, 143 insertions(+), 51 deletions(-) -- 1.9.1