On Monday 04 May 2009 08:53:07 Nicholas A. Bellinger wrote: > On Sat, 2009-05-02 at 18:22 +0800, Sheng Yang wrote: > > On Thu, Apr 30, 2009 at 01:22:54PM -0700, Nicholas A. Bellinger wrote: > > > Greetings KVM folks, > > > > > > I wondering if any information exists for doing SR-IOV on the new VT-d > > > capable chipsets with KVM..? From what I understand the patches for > > > doing this with KVM are floating around, but I have been unable to find > > > any user-level docs for actually making it all go against a upstream > > > v2.6.30-rc3 code.. > > > > > > So far I have been doing IOV testing with Xen 3.3 and 3.4.0-pre, and I > > > am really hoping to be able to jump to KVM for single-function and and > > > then multi-function SR-IOV. I know that the VM migration stuff for IOV > > > in Xen is up and running, and I assume it is being worked in for KVM > > > instance migration as well..? This part is less important (at least > > > for me :-) than getting a stable SR-IOV setup running under the KVM > > > hypervisor.. Does anyone have any pointers for this..? > > > > > > Any comments or suggestions are appreciated! > > > > Hi Nicholas > > > > The patches are not floating around now. As you know, SR-IOV for Linux > > have been in 2.6.30, so then you can use upstream KVM and qemu-kvm(or > > recent released kvm-85) with 2.6.30-rc3 as host kernel. And some time > > ago, there are several SRIOV related patches for qemu-kvm, and now they > > all have been checked in. > > > > And for KVM, the extra document is not necessary, for you can simple > > assign a VF to guest like any other devices. And how to create VF is > > specific for each device driver. So just create a VF then assign it to > > KVM guest is fine. > > Greetings Sheng, > > So, I have been trying the latest kvm-85 release on a v2.6.30-rc3 > checkout from linux-2.6.git on a CentOS 5u3 x86_64 install on Intel > IOH-5520 based dual socket Nehalem board. I have enabled DMAR and > Interrupt Remapping my KVM host using v2.6.30-rc3 and from what I can > tell, the KVM_CAP_* defines from libkvm are enabled with building kvm-85 > after './configure --kerneldir=/usr/src/linux-2.6.git' and the PCI > passthrough code is being enabled in kvm-85/qemu/hw/device-assignment.c > AFAICT.. > > >From there, I use the freshly installed qemu-x86_64-system binary to > > start a Debian 5 x86_64 HVM (that previously had been moving network > packets under Xen for PCIe passthrough). I see the MSI-X interrupt > remapping working on the KVM host for the passed -pcidevice, and the > MMIO mappings from the qemu build that I also saw while using > Xen/qemu-dm built with PCI passthrough are there as well.. > Hi Nicholas > But while the KVM guest is booting, I see the following exception(s) > from qemu-x86_64-system for one of the VFs for a multi-function PCIe > device: > > BUG: kvm_destroy_phys_mem: invalid parameters (slot=-1) This one is mostly harmless. > > I try with one of the on-board e1000e ports (02:00.0) and I see the same > exception along with some MSI-X exceptions from qemu-x86_64-system in > KVM guest.. However, I am still able to see the e1000e and the other > vxge multi-function device with lspci, but I am unable to dhcp or ping > with the e1000e and VF from multi-function device fails to register the > MSI-X interrupt in the guest.. Did you see the interrupt in the guest and host side? I think you can try on- board e1000e for MSI-X first. And please ensure correlated driver have been loaded correctly. And what do you mean by "some MSI-X exceptions"? Better with the log. > > Soooo, I enabled the debugging code in kvm-85/qemu/hw/device-assignment.c > and see the PAGE aligned MMIO memory for the passed PCIe device is being > released during the BUG exceptions above.. Is there something else I > should be looking at..? That part of memory should be released for trap MMIO for MSI-X table. > I have pci-stub enabled, and I unbind 02:00.0 > from /sys/bus/pci/drivers/e1000e/unbind successfully (just like with Xen > and pciback), but I am unable to do the 'echo -n 02:00.0 > > > /sys/bus/pci/drivers/pci-stub/bind' (it returns write error, no such > > device, with no dmesg output) on the KVM host running v2.6.30-rc3. Is > this supposed to happen on v2.6.30-rc3 with pci-stub..? Maybe you need "echo 0000:02:00.0 > /sys/bus/pci/drivers/pci-stub/bind"? > I am also using > the the kvm-85 source dist kvm_intel.ko and kvm.ko kernel modules. Is > there something I am missing when building kvm-85 for SR-IOV passthrough..? I think the first thing is to confirm that device assignment work in your environment, using on-board card. You can also refer to http://www.linux-kvm.org/page/How_to_assign_devices_with_VT-d_in_KVM And you can post debug_device_assignment=1 log and qemu log and the tail of dmesg as well. Thanks! -- regards Yang, Sheng > > Also FYI, I am having to use pci=resource_alignment= > because the BIOS does not PAGE_SIZE align the MMIO BARs for my > multi-function devices.. > > Also, I tried with disabling the DMAR with the Intel IOMMU passthrough > from this patch: > > https://lists.linux-foundation.org/pipermail/iommu/2009-April/001339.html > > that did not make it into v2.6.30-rc3. The patch logic was enabled but > still I saw the same kvm exceptions from qemu-system-x86_64. > > Anyways, I am going to give it a shot with the Fedora 11 x86_64 Preview > and see if it works as expected with a IOH-5520 chipset with the AMI > BIOS on a Tyan S7010 with Xeon 5520s. Hopefully this is just a kvm-85 > build and/or install issue I am seeing on my CentOS 5u3 install (that has a > Xen PCIe passthrough setup on it as well) with v2.6.30-rc3. I will try on > a fresh install on a distro with the new KVM logic and see what happens. > > :-) > > Thanks for your comments! > > --nab -- 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
