Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757259AbaGNUSb (ORCPT ); Mon, 14 Jul 2014 16:18:31 -0400 Received: from aserp1040.oracle.com ([141.146.126.69]:33616 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754870AbaGNUSa (ORCPT ); Mon, 14 Jul 2014 16:18:30 -0400 Date: Mon, 14 Jul 2014 16:18:17 -0400 From: Konrad Rzeszutek Wilk To: Sander Eikelenboom Cc: konrad@kernel.org, xen-devel@lists.xenproject.org, boris.ostrovsky@oracle.com, david.vrabel@citrix.com, linux-kernel@vger.kernel.org Subject: Re: [Xen-devel] [PATCH v4] PCI back fixes for 3.17. Message-ID: <20140714201817.GD23791@laptop.dumpdata.com> References: <20140714172225.GA10497@laptop.dumpdata.com> <652296445.20140714192923@eikelenboom.it> <20140714173753.GB12920@laptop.dumpdata.com> <9210423415.20140714194304@eikelenboom.it> <20140714174525.GD12920@laptop.dumpdata.com> <1332864311.20140714202433@eikelenboom.it> <20140714184547.GA18896@laptop.dumpdata.com> <1499016487.20140714210129@eikelenboom.it> <20140714195405.GA20567@laptop.dumpdata.com> <6110472183.20140714221618@eikelenboom.it> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6110472183.20140714221618@eikelenboom.it> User-Agent: Mutt/1.5.23 (2014-03-12) X-Source-IP: ucsinet22.oracle.com [156.151.31.94] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 14, 2014 at 10:16:18PM +0200, Sander Eikelenboom wrote: > > Monday, July 14, 2014, 9:54:05 PM, you wrote: > > > On Mon, Jul 14, 2014 at 09:01:29PM +0200, Sander Eikelenboom wrote: > >> > >> Monday, July 14, 2014, 8:45:47 PM, you wrote: > >> > >> > On Mon, Jul 14, 2014 at 08:24:33PM +0200, Sander Eikelenboom wrote: > >> >> > >> >> Monday, July 14, 2014, 7:45:25 PM, you wrote: > >> >> > >> >> > On Mon, Jul 14, 2014 at 07:43:04PM +0200, Sander Eikelenboom wrote: > >> >> >> > >> >> >> Monday, July 14, 2014, 7:37:53 PM, you wrote: > >> >> >> > >> >> >> >> >> Ad B) > >> >> >> >> >> > >> >> >> >> >> root@dom0:~# xl pci-list router > >> >> >> >> >> Vdev Device > >> >> >> >> >> 05.0 0000:00:1b.0 > >> >> >> >> >> > >> >> >> >> >> root@dom0:~# xl pci-assignable-list > >> >> >> >> >> 0000:02:00.0 > >> >> >> >> >> > >> >> >> >> >> root@dom0:~# xl pci-detach router 00:1b.0 > >> >> >> >> >> dmesg shows: > >> >> >> >> >> [ 199.742668] pciback 0000:00:1b.0: restoring config space at offset 0x10 (was 0x4, writing 0xf7d30004) > >> >> >> >> >> [ 199.743527] pciback 0000:00:1b.0: restoring config space at offset 0xc (was 0x0, writing 0x10) > >> >> >> >> >> [ 199.744321] pciback 0000:00:1b.0: restoring config space at offset 0x4 (was 0x100000, writing 0x100006) > >> >> >> >> >> [ 199.757184] xen-pciback pci-1-0: xen_pcibk_xenbus_remove freeing pdev @ 0xffff8800589fce40 > >> >> >> >> >> [ 199.758139] xen-pciback pci-1-0: xen_pcibk_disconnect pdev @ 0xffff8800589fce40 > >> >> >> >> >> [ 199.862595] xen: xen_unregister_device_domain_owner > >> >> >> >> >> > >> >> >> >> >> xl dmesg shows: > >> >> >> >> >> (XEN) [2014-07-14 16:28:29] memory_map:remove: dom1 gfn=f3070 mfn=f7d30 nr=4 > >> >> >> >> >> (XEN) [2014-07-14 16:28:29] io.c:322: d1: unbind: m_gsi=22 g_gsi=36 dev=00:00.5 intx=0 > >> >> >> >> >> (XEN) [2014-07-14 16:28:29] io.c:390: d1 unmap: m_irq=22 dev=00:00.5 intx=0 > >> >> >> >> >> (XEN) [2014-07-14 16:28:29] [VT-D]iommu.c:1579: d1:PCIe: unmap 0000:00:1b.0 > >> >> >> >> >> (XEN) [2014-07-14 16:28:29] [VT-D]iommu.c:1440: d0:PCIe: map 0000:00:1b.0 > >> >> >> >> >> > >> >> >> >> >> root@dom0:~# xl pci-list router > >> >> >> >> >> root@dom0:~# xl pci-assignable-list > >> >> >> >> >> 0000:00:1b.0 > >> >> >> >> >> 0000:02:00.0 > >> >> >> >> >> > >> >> >> >> >> root@dom0:~# xl pci-assignable-remove 00:1b.0 > >> >> >> >> >> dmesg shows: > >> >> >> >> >> [ 318.827415] xen: xen_unregister_device_domain_owner > >> >> >> >> >> [ 318.828771] xen: xen_unregister_device_domain_owner: ENODEV > >> >> >> >> >> [ 318.930869] pciback 0000:00:1b.0: restoring config space at offset 0x10 (was 0x4, writing 0xf7d30004) > >> >> >> >> >> [ 318.933435] pciback 0000:00:1b.0: restoring config space at offset 0xc (was 0x0, writing 0x10) > >> >> >> >> >> [ 318.935877] pciback 0000:00:1b.0: restoring config space at offset 0x4 (was 0x100000, writing 0x100006) > >> >> >> >> >> > >> >> >> >> >> root@dom0:~# xl pci-list router > >> >> >> >> >> root@dom0:~# xl pci-assignable-list > >> >> >> >> >> 0000:02:00.0 > >> >> >> >> >> > >> >> >> >> >> > >> >> >> >> > >> >> >> >> > And if you do: > >> >> >> >> > >> >> >> >> > # xl pci-detach router 02:00.0 > >> >> >> >> > >> >> >> > >> >> >> > Err, I meant > >> >> >> > # xl pci-assignable-remove 02:00.0 > >> >> >> > >> >> >> Ah ok .. so that is: > >> >> >> remove a device from pciback that has never been assigned to any guest .. > >> >> >> > >> >> >> will also give that a go .. although that probably won't be a problem. > >> >> > >> >> > Right. So I think it all works as expected? That is if you have > >> >> > two PCI devices assigned to a guest and want to re-use them you > >> >> > have to do the 'pci-detach' twice and then follow that with > >> >> > 'pci-assignable-remove' twice as well? > >> >> > >> >> Well except that's not what i want :-) .. that's about the same as shutting down > >> >> the guest .. and indeed that works :-) > >> >> > >> >> What i want to do is to remove just *one* device and leave the other one in the guest. > >> >> > >> >> The one that i remove .. i would like to be able to remove it from being > >> >> assignable .. (rebind it in dom0) and/or assign it to another guest. > >> > >> > Aha > >> >> > >> >> And that fails because pciback still thinks the guest owns the device .. > >> >> while libxl thinks it doesn't (outcome of xl pci-assignable-list). > >> > >> > Oh > >> >> > >> >> When doing the: > >> >> > >> >> # xl pci-assignable-list > >> >> 0000:02:00.0 > >> >> # xl pci-assignable-remove 02:00.0 > >> >> dmesg shows: > >> >> [ 443.292951] xen: xen_unregister_device_domain_owner > >> >> [ 443.294308] xen: xen_unregister_device_domain_owner: ENODEV > >> >> [ 443.398827] pciback 0000:02:00.0: restoring config space at offset 0x3c (was 0x100, writing 0x104) > >> >> [ 443.400797] pciback 0000:02:00.0: restoring config space at offset 0x10 (was 0x4, writing 0xf7c00004) > >> >> [ 443.401713] pciback 0000:02:00.0: restoring config space at offset 0x4 (was 0x100000, writing 0x100006) > >> >> > >> >> which i think is what is expected .. > >> > >> > Right. > >> > >> >> > >> >> > >> >> Hmm /sys/bus/pci/drivers/pciback doesn't shed much light, because in the state > >> >> just after a xl pci-detach, the device is still registred by pciback (from dom0's > >> >> view) which is correct, what is wrong is that pciback still seems to think that > >> >> it is in turn still owned by the guest. That doesn't get reflected in the info > >> >> available in the /sys dir. > >> > >> > Oh > >> >> > >> >> Ok over to xen-store ... > >> > >> > I think I had a patch for that in libxl. It was the order of operations it was > >> > doing - it did the 'unbind' first and then it did the XenBus operations. > >> > >> >> > >> >> first a diff between the booted guest with two devices passed through and the > >> >> state after the "xl pci-detach router 00:1b.0" > >> >> > >> >> root@creanuc:~# diff -U10 xs-before-detach-first.txt xs-after-detach-first.txt > >> >> --- xs-before-detach-first.txt 2014-07-14 19:56:23.233576000 +0200 > >> >> +++ xs-after-detach-first.txt 2014-07-14 20:00:00.053576000 +0200 > >> >> @@ -185,35 +185,29 @@ > >> >> feature-rx-flip = "0" > >> >> feature-split-event-channels = "1" > >> >> multi-queue-max-queues = "4" > >> >> hotplug-status = "connected" > >> >> pci = "" > >> >> 1 = "" > >> >> 0 = "" > >> >> frontend = "/local/domain/1/device/pci/0" > >> >> frontend-id = "1" > >> >> online = "1" > >> >> - state = "3" > >> >> + state = "7" > >> >> domain = "router" > >> >> key-0 = "0000:02:00.0" > >> >> dev-0 = "0000:02:00.0" > >> >> vdevfn-0 = "28" > >> >> opts-0 = "msitranslate=0,power_mgmt=0,permissive=0" > >> >> state-0 = "3" > >> >> - key-1 = "0000:00:1b.0" > >> >> - dev-1 = "0000:00:1b.0" > >> >> - vdevfn-1 = "30" > >> >> - opts-1 = "msitranslate=0,power_mgmt=0,permissive=0" > >> >> - state-1 = "3" > >> >> - num_devs = "2" > >> >> + num_devs = "1" > >> >> vdev-0 = "0000:00:00.00" > >> >> - vdev-1 = "0000:00:01.00" > >> >> root-0 = "0000:00" > >> >> root_num = "1" > >> >> 1 = "" > >> >> vm = "/vm/a102d97e-8388-414e-97e5-cc394656c47d" > >> >> name = "router" > >> >> cpu = "" > >> >> 0 = "" > >> >> availability = "online" > >> >> 1 = "" > >> >> availability = "online" > >> >> > >> >> It seems ok, perhaps apart from the general pci state going from 3 to 7 ? > >> >> Haven't looked up the exact states, but since only one domain is removes i would > >> >> still expect it to be 3 ? > >> > >> > 7 is Reconfiguring which is what it should move to (to update the XenBus). > >> > >> Ok, but that should than be acknowledged somewhere by someone i suppose .. and > >> not stay in that state ? > >> > >> >> > >> >> > >> >> Now a diff before and after the "xl pci-assignable-remove 00:1b.0" > >> >> diff xs-after-detach-first.txt xs-after-pci-assignable-remove-first.txt is > >> >> empty, as expected since this is a pciback only thing now involving any guest. > >> >> > >> >> > >> >> And now the last diff, between the state before and after the "xl pci-detach > >> >> 02:00.0" removing the last pci device from the guest. > >> >> > >> >> root@creanuc:~# diff -U5 xs-after-pci-assignable-remove-first.txt xs-after-pci-detach-second.txt > >> >> --- xs-after-pci-assignable-remove-first.txt 2014-07-14 20:00:45.161576000 +0200 > >> >> +++ xs-after-pci-detach-second.txt 2014-07-14 20:01:20.177576000 +0200 > >> >> @@ -184,27 +184,10 @@ > >> >> feature-rx-copy = "1" > >> >> feature-rx-flip = "0" > >> >> feature-split-event-channels = "1" > >> >> multi-queue-max-queues = "4" > >> >> hotplug-status = "connected" > >> >> - pci = "" > >> >> - 1 = "" > >> >> - 0 = "" > >> >> - frontend = "/local/domain/1/device/pci/0" > >> >> - frontend-id = "1" > >> >> - online = "1" > >> >> - state = "7" > >> >> - domain = "router" > >> >> - key-0 = "0000:02:00.0" > >> >> - dev-0 = "0000:02:00.0" > >> >> - vdevfn-0 = "28" > >> >> - opts-0 = "msitranslate=0,power_mgmt=0,permissive=0" > >> >> - state-0 = "3" > >> >> - num_devs = "1" > >> >> - vdev-0 = "0000:00:00.00" > >> >> - root-0 = "0000:00" > >> >> - root_num = "1" > >> >> 1 = "" > >> >> vm = "/vm/a102d97e-8388-414e-97e5-cc394656c47d" > >> >> name = "router" > >> >> cpu = "" > >> >> 0 = "" > >> >> @@ -249,15 +232,10 @@ > >> >> event-channel-rx = "25" > >> >> request-rx-copy = "1" > >> >> feature-rx-notify = "1" > >> >> feature-sg = "1" > >> >> feature-gso-tcpv4 = "1" > >> >> - pci = "" > >> >> - 0 = "" > >> >> - backend = "/local/domain/0/backend/pci/1/0" > >> >> - backend-id = "0" > >> >> - state = "1" > >> >> control = "" > >> >> shutdown = "" > >> >> platform-feature-multiprocessor-suspend = "1" > >> >> platform-feature-xs_reset_watches = "1" > >> >> hvmloader = "" > >> >> > >> >> That seems ok. > >> >> > >> >> So apart from that perhaps incorrect general pci state change, the info in > >> >> xenstore seems to be OK. > >> >> > >> >> So it does seem to be a lack of pciback receiving a confirm from libxl / qemu that the > >> >> device is indeed removed from the guest for the final deregistring of the > >> >> ownership. > >> >> > >> >> Because after a pci-detach the pci device is: > >> >> - removed from xen-store as attached to the guest > >> >> - the iommu has assigned/mapped it back to dom0 > >> >> - xl pci-assignable-list shows it as assignable again > >> >> > >> >> So only pciback is the only one left out of the party :-) > >> >> Couldn't it be somehow tied to the iommu events, since it should be in sync with that i suppose ? > >> > >> > >> > Let me find out what is up with this. Once the device > >> > is de-assigned from a guest (even if forcefully) it should > >> > be possible to assign it to another. > >> > >> Yes .. at least for the rebinding to dom0 case, because the > >> pci-assignable-remove seems to do it forcefully now. But i haven't tried what it > >> does when reassigning to another guest (if it forcefully swaps ownership then, > >> since the pci-assignable-remove isn't involved then). > >> > >> Will give the xen patch a try. > > > I found out what the problem is. It has been in the code for eons and > > I think we never tested for it because the older toolstack (xend) would > > do things differently. > > That .. and probably not many people testing .. > Until now i used the automatic assign and deassign on guest creation > and shutdown which doesn't exhibit this problem. > > > The issue here is: > > > 1) xl pci-detach > > > 'xl' removes the whole device from the XenStore, so from: > > domain = "USB" > > > vdevfn-0 = "28" > > opts-0 = "msitranslate=0,power_mgmt=0,permissive=0" > > state-0 = "3" > > vdev-0 = "0000:00:00.00" > > root-0 = "0000:00" > > key-0 = "0000:07:00.0" > > dev-0 = "0000:07:00.0" > > > key-1 = "0000:04:00.0" > > dev-1 = "0000:04:00.0" > > vdevfn-1 = "30" > > opts-1 = "msitranslate=0,power_mgmt=0,permissive=0" > > state-1 = "3" > > num_devs = "2" > > vdev-1 = "0000:00:01.00" > > root_num = "1" > > > it just yanks out the '*-1' values, so we have: > > > domain = "USB" > > > vdevfn-0 = "28" > > opts-0 = "msitranslate=0,power_mgmt=0,permissive=0" > > state-0 = "3" > > vdev-0 = "0000:00:00.00" > > root-0 = "0000:00" > > key-0 = "0000:07:00.0" > > dev-0 = "0000:07:00.0" > > > num_devs = "1" > > > While if the frontend was PV (so xen-pcifront) it would first but > > the state-1 to 5 (Closed) which would let the Xen pciback deallocate this. > > > Anyhow, Xen pciback should be able to deal with this, but the patch > > is going to take a bit of time to figure out. > > > Thank you for reporting it and helping me with the XenStore output to > > narrow down the culprit! > > The thing i don't understand then is: > How is it different for the last (or all ) device(s) ? > (since the last device (or removing all devices) before doing the > assignable-remove doesn't trigger the warning) > > Or does the complete removal of the pci-part of the tree in xenstore trigger something ? Yup. It removes the whole 'pci' directory in XenStore which triggers in Xen pciback the code to deal with that. > > You know if you got a patch cooked up, i'm more than happy to test ! Hehe! > > -- > Sander > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/