I found these patches in xen-unstable qemu.git. I've not tried to reproduce it as my machine(s) do not have an IOMMU, but the bug is pretty obvious in retrospect. 60b80e3ee319e908069d1603e5b73f815acdffac passthrough: magic ioport protocol no longer unplugs passthrough NICs f187eeb8546405d57eb421cdd329d804ee734d23 passthrough: magic protocol passthrough fix no-passthrough compile
Just a note that this affects RHEL6 guests only.
Related bugs: - bug 515238 introduced the regression - RHEL6.0 bug 632021 masked it, but it will (re)appear on 6.1
Paolo, can you provide a ptr to the xen-unstable qemu.git tree? thanks... Don
[remote "xen"] url = git://xenbits.xensource.com/qemu-xen-unstable.git fetch = +refs/heads/*:refs/remotes/xen/*
moving to 5.7 per triage assessment.
Fix built into xen-3.0.3-126.el5
Verified with xen-3.0.3-129.el5. $ cat guest.cfg ... pci = ['0000:03:10.2','0000:03:10.3'] vif = ["mac=00:16:36:55:50:21,bridge=xenbr0,script=vif-bridge,type=ioemu", "mac=00:16:36:55:50:22,bridge=xenbr0,script=vif-bridge,type=ioemu"] ... reproduced with xen-3.0.3-120.el5 + RHEL6.1 snapshot4 (kernel-2.6.32-131.0.1), (no xen_emul_unplug=* parameter in guest kernel cmdline), both the pass-through nics and xen emulated nics are unpluged. after update to xen-3.0.3-129.el5, boot up guest with same configuration, can see the pass-through nics within the guest, so the fix works.
Technical note added. If any revisions are required, please edit the "Technical Notes" field accordingly. All revisions will be proofread by the Engineering Content Services team. New Contents: When a Network Interface Card (NIC) was disconnected by the qemu-dm daemon, all associated pass-through NICs, such as various PCI devices, were disconnected as well. This bug has been fixed and now the pass-through NICs remain connected and functioning in the described scenario.
qemu-dm is not a daemon; mentioned explicitly which guests request unplug to qemu-dm.
Technical note updated. If any revisions are required, please edit the "Technical Notes" field accordingly. All revisions will be proofread by the Engineering Content Services team. Diffed Contents: @@ -1 +1 @@ -When a Network Interface Card (NIC) was disconnected by the qemu-dm daemon, all associated pass-through NICs, such as various PCI devices, were disconnected as well. This bug has been fixed and now the pass-through NICs remain connected and functioning in the described scenario.+When a Red Hat Enterprise Linux 6.1 fully-virtualized Xen guest requested unplug of emulated network cards, qemu-dm would also disconnect host network cards that were passed-through to the guest. This bug has been fixed and now the pass-through NICs remain functioning for Red Hat Enterprise Linux 6.1 guests.
Technical note updated. If any revisions are required, please edit the "Technical Notes" field accordingly. All revisions will be proofread by the Engineering Content Services team. Diffed Contents: @@ -1 +1 @@ -When a Red Hat Enterprise Linux 6.1 fully-virtualized Xen guest requested unplug of emulated network cards, qemu-dm would also disconnect host network cards that were passed-through to the guest. This bug has been fixed and now the pass-through NICs remain functioning for Red Hat Enterprise Linux 6.1 guests.+When a Red Hat Enterprise Linux 6.1 fully-virtualized Xen guest requested an unplug of emulated network cards, the qemu-dm device model would also disconnect host network cards that were passed-through to the guest. This bug has been fixed, and now the pass-through NICs (Network Interface Cards) remain functioning for Red Hat Enterprise Linux 6.1 guests.
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on therefore solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHBA-2011-1070.html