On Sun, Dec 10, 2023 at 12:06 PM Akihiko Odaki <akihiko.od...@daynix.com> wrote: > > Introduction > ------------ > > This series is based on the RFC series submitted by Yui Washizu[1]. > See also [2] for the context. > > This series enables SR-IOV emulation for virtio-net. It is useful > to test SR-IOV support on the guest, or to expose several vDPA devices > in a VM. vDPA devices can also provide L2 switching feature for > offloading though it is out of scope to allow the guest to configure > such a feature. > > The PF side code resides in virtio-pci. The VF side code resides in > the PCI common infrastructure, but it is restricted to work only for > virtio-net-pci because of lack of validation. > > User Interface > -------------- > > A user can configure a SR-IOV capable virtio-net device by adding > virtio-net-pci functions to a bus. Below is a command line example: > -netdev user,id=n -netdev user,id=o > -netdev user,id=p -netdev user,id=q > -device pcie-root-port,id=b > -device virtio-net-pci,bus=b,addr=0x0.0x3,netdev=q,sriov-pf=f > -device virtio-net-pci,bus=b,addr=0x0.0x2,netdev=p,sriov-pf=f > -device virtio-net-pci,bus=b,addr=0x0.0x1,netdev=o,sriov-pf=f > -device virtio-net-pci,bus=b,addr=0x0.0x0,netdev=n,id=f > > The VFs specify the paired PF with "sriov-pf" property. The PF must be > added after all VFs. It is user's responsibility to ensure that VFs have > function numbers larger than one of the PF, and the function numbers > have a consistent stride.
This seems not user friendly. Any reason we can't just allow user to specify the stride here? Btw, I vaguely remember qemu allows the params to be accepted as a list. If this is true, we can accept a list of netdev here? > > Keeping VF instances > -------------------- > > A problem with SR-IOV emulation is that it needs to hotplug the VFs as > the guest requests. Previously, this behavior was implemented by > realizing and unrealizing VFs at runtime. However, this strategy does > not work well for the proposed virtio-net emulation; in this proposal, > device options passed in the command line must be maintained as VFs > are hotplugged, but they are consumed when the machine starts and not > available after that, which makes realizing VFs at runtime impossible. Could we store the device options in the PF? Thanks > > As an strategy alternative to runtime realization/unrealization, this > series proposes to reuse the code to power down PCI Express devices. > When a PCI Express device is powered down, it will be hidden from the > guest but will be kept realized. This effectively implements the > behavior we need for the SR-IOV emulation. > > Summary > ------- > > Patch [1, 5] refactors the PCI infrastructure code. > Patch [6, 10] adds user-created SR-IOV VF infrastructure. > Patch 11 makes virtio-pci work as SR-IOV PF for user-created VFs. > Patch 12 allows user to create SR-IOV VFs with virtio-net-pci. > > [1] > https://patchew.org/QEMU/1689731808-3009-1-git-send-email-yui.wash...@gmail.com/ > [2] > https://lore.kernel.org/all/5d46f455-f530-4e5e-9ae7-13a2297d4...@daynix.com/ > > Co-developed-by: Yui Washizu <yui.wash...@gmail.com> > Signed-off-by: Akihiko Odaki <akihiko.od...@daynix.com> > --- > Changes in v2: > - Changed to keep VF instances. > - Link to v1: > https://lore.kernel.org/r/20231202-sriov-v1-0-32b3570f7...@daynix.com > > --- > Akihiko Odaki (12): > hw/pci: Initialize PCI multifunction after realization > hw/pci: Determine if rombar is explicitly enabled > hw/pci: Do not add ROM BAR for SR-IOV VF > vfio: Avoid inspecting option QDict for rombar > hw/qdev: Remove opts member > pcie_sriov: Reuse SR-IOV VF device instances > pcie_sriov: Release VFs failed to realize > pcie_sriov: Ensure PF and VF are mutually exclusive > pcie_sriov: Check PCI Express for SR-IOV PF > pcie_sriov: Allow user to create SR-IOV device > virtio-pci: Implement SR-IOV PF > virtio-net: Implement SR-IOV VF > > docs/pcie_sriov.txt | 8 +- > include/hw/pci/pci.h | 2 +- > include/hw/pci/pci_device.h | 13 +- > include/hw/pci/pcie_sriov.h | 25 ++- > include/hw/qdev-core.h | 4 - > hw/core/qdev.c | 1 - > hw/net/igb.c | 3 +- > hw/nvme/ctrl.c | 3 +- > hw/pci/pci.c | 98 +++++++----- > hw/pci/pci_host.c | 4 +- > hw/pci/pcie.c | 4 +- > hw/pci/pcie_sriov.c | 360 > +++++++++++++++++++++++++++++++++----------- > hw/vfio/pci.c | 3 +- > hw/virtio/virtio-net-pci.c | 1 + > hw/virtio/virtio-pci.c | 7 + > system/qdev-monitor.c | 12 +- > 16 files changed, 395 insertions(+), 153 deletions(-) > --- > base-commit: 4705fc0c8511d073bee4751c3c974aab2b10a970 > change-id: 20231202-sriov-9402fb262be8 > > Best regards, > -- > Akihiko Odaki <akihiko.od...@daynix.com> >
