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Date: Mon, 14 Jul 2014 19:29:23 +0200 From: Sander Eikelenboom <linux@...elenboom.it> To: Konrad Rzeszutek Wilk <konrad.wilk@...cle.com> CC: konrad@...nel.org, xen-devel@...ts.xenproject.org, <boris.ostrovsky@...cle.com>, <david.vrabel@...rix.com>, <linux-kernel@...r.kernel.org> Subject: Re: [Xen-devel] [PATCH v4] PCI back fixes for 3.17. Monday, July 14, 2014, 7:22:25 PM, you wrote: > On Mon, Jul 14, 2014 at 06:37:55PM +0200, Sander Eikelenboom wrote: >> >> Friday, July 11, 2014, 10:08:47 PM, you wrote: >> >> > Please see this set of patches which are fixes to Xen pciback >> > for 3.17. They are also located at: >> >> > git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen.git devel/pciback-3.17.v4 >> >> > These patches do not include the PCI bus reset/slot code as we are still >> > discussing that. >> >> > Konrad Rzeszutek Wilk (5): >> > xen-pciback: Document the various parameters and attributes in SysFS >> > xen/pciback: Don't deadlock when unbinding. >> > xen/pciback: Include the domain id if removing the device whilst still in use >> > xen/pciback: Print out the domain owning the device. >> > xen/pciback: Remove tons of dereferences >> >> > Documentation/ABI/testing/sysfs-driver-pciback | 25 +++++++++++++++ >> > drivers/xen/xen-pciback/passthrough.c | 9 ++++- >> > drivers/xen/xen-pciback/pci_stub.c | 41 +++++++++++++------------ >> > drivers/xen/xen-pciback/pciback.h | 7 ++-- >> > drivers/xen/xen-pciback/vpci.c | 9 ++++- >> > drivers/xen/xen-pciback/xenbus.c | 4 +- >> > 6 files changed, 67 insertions(+), 28 deletions(-) >> >> Hi Konrad / David, >> >> Thanks for the fixes in this series, i just tested this series and noticed (as >> somewhat expected :-) ) it's still lacking a fix for the bug that pciback >> doesn't properly free / disown a device from a HVM guest. >> >> This only happens when using "xl pci-detach domain BDF" >> AND >> when the guest has more than one pci device attached and you remove only ONE of >> them. >> >> The pci-detach doesn't show an error, the device is removed from the guest, but >> it seems it is not internally freed in pciback. >> >> Below is the sequence and outcome (with some added printk's) for two situations: >> A) Guest has only one pci-device passed through which is then removed, as you can see >> it's freed in pciback as well. >> >> B) Guest has two pci-devices passed through from which one is then removed. >> After that the second is removed as well. >> >> >From what i recall Konrad thought it could be due to the guest being a HVM and thus the signaling is different from a >> PV-Guest (no pci-front confirming the removal via xenbus). But since it does get freed when it is the last device attached to the guest >> i don't know if that's completely true. >> It's now semi-fixed when doing the 'xl pci-assignable-remove', that seems to force unregistring the device owner, however something still doesn't seem >> right see the second "xl pci-detach" removing the last device from (A), it takes about a minute instead of not more than a second. >> >> Also note that when on calling "xl pci-assignable-remove" for the last (or only) passed through device for a guest, you don't get the warning messages about >> the device being 'in-use' >> >> Completely below an diff of the added printk's. >> >> -- >> >> Sander >> >> >> Ad A) >> >> root@...0:~# xl pci-list router >> Vdev Device >> 05.0 0000:02:00.0 >> 06.0 0000:00:1b.0 >> >> root@...0:~# xl pci-assignable-list >> >> root@...0:~# xl pci-detach router 00:1b.0 >> >> dmesg shows: >> [ 434.839156] pciback 0000:00:1b.0: restoring config space at offset 0x10 (was 0x4, writing 0xf7d30004) >> [ 434.841745] pciback 0000:00:1b.0: restoring config space at offset 0xc (was 0x0, writing 0x10) >> [ 434.844205] pciback 0000:00:1b.0: restoring config space at offset 0x4 (was 0x100000, writing 0x100006) >> >> xl dmesg shows: >> (XEN) [2014-07-14 16:02:27] memory_map:remove: dom1 gfn=f3070 mfn=f7d30 nr=4 >> (XEN) [2014-07-14 16:02:27] io.c:322: d1: unbind: m_gsi=22 g_gsi=40 dev=00:00.6 intx=0 >> (XEN) [2014-07-14 16:02:27] io.c:390: d1 unmap: m_irq=22 dev=00:00.6 intx=0 >> (XEN) [2014-07-14 16:02:27] [VT-D]iommu.c:1579: d1:PCIe: unmap 0000:00:1b.0 >> (XEN) [2014-07-14 16:02:27] [VT-D]iommu.c:1440: d0:PCIe: map 0000:00:1b.0 >> >> root@...0:~# xl pci-assignable-list >> 0000:00:1b.0 >> >> root@...0:~# xl pci-assignable-remove 00:1b.0 >> dmesg shows: >> [ 609.246406] xen_pciback: ****** removing device 0000:00:1b.0 while still in-use by domain 1! ****** >> [ 609.248985] xen_pciback: ****** driver domain may still access this device's i/o resources! >> [ 609.251344] xen_pciback: ****** shutdown driver domain before binding device >> [ 609.253291] xen_pciback: ****** to other drivers or domains >> [ 609.355083] xen: xen_unregister_device_domain_owner >> [ 609.356448] xen: xen_unregister_device_domain_owner >> [ 609.357789] xen: xen_unregister_device_domain_owner: ENODEV >> [ 609.463125] pciback 0000:00:1b.0: restoring config space at offset 0x10 (was 0x4, writing 0xf7d30004) >> [ 609.465692] pciback 0000:00:1b.0: restoring config space at offset 0xc (was 0x0, writing 0x10) >> [ 609.468137] pciback 0000:00:1b.0: restoring config space at offset 0x4 (was 0x100000, writing 0x100006) >> >> root@...0:~# xl pci-list router >> Vdev Device >> 05.0 0000:02:00.0 >> >> root@...0:~# xl pci-detach router 02:00.0 >> dmesg shows: >> [ 930.571300] pciback 0000:02:00.0: restoring config space at offset 0x3c (was 0x100, writing 0x104) >> [ 930.574140] pciback 0000:02:00.0: restoring config space at offset 0x10 (was 0x4, writing 0xf7c00004) >> [ 930.576859] pciback 0000:02:00.0: restoring config space at offset 0x4 (was 0x100000, writing 0x100006) >> [ 930.614554] xen-pciback pci-1-0: xen_pcibk_xenbus_remove freeing pdev @ 0xffff880058fcb480 >> [ 930.615606] xen-pciback pci-1-0: xen_pcibk_disconnect pdev @ 0xffff880058fcb480 >> [ 930.719110] xen: xen_unregister_device_domain_owner >> >> xl dmesg shows: >> (XEN) [2014-07-14 16:10:43] [VT-D]iommu.c:1579: d1:PCIe: unmap 0000:02:00.0 >> (XEN) [2014-07-14 16:10:43] [VT-D]iommu.c:1440: d0:PCIe: map 0000:02:00.0 >> (XEN) [2014-07-14 16:11:46] memory_map:remove: dom1 gfn=f3074 mfn=f7c00 nr=2 >> (XEN) [2014-07-14 16:11:46] io.c:322: d1: unbind: m_gsi=18 g_gsi=36 dev=00:00.5 intx=0 >> (XEN) [2014-07-14 16:11:46] io.c:390: d1 unmap: m_irq=18 dev=00:00.5 intx=0 >> >> root@...0:~# xl pci-assignable-list >> 0000:02:00.0 >> >> root@...0:~# xl pci-assignable-remove 02:00.0 >> dmesg shows: >> [ 1468.561071] xen: xen_unregister_device_domain_owner >> [ 1468.562431] xen: xen_unregister_device_domain_owner: ENODEV >> [ 1468.667271] pciback 0000:02:00.0: restoring config space at offset 0x3c (was 0x100, writing 0x104) >> [ 1468.670119] pciback 0000:02:00.0: restoring config space at offset 0x10 (was 0x4, writing 0xf7c00004) >> [ 1468.672857] pciback 0000:02:00.0: restoring config space at offset 0x4 (was 0x100000, writing 0x100006) >> >> > At this point if you do: > #xl pci-assignable-list > I presume you don't see anything (nods) >> Ad B) >> >> root@...0:~# xl pci-list router >> Vdev Device >> 05.0 0000:00:1b.0 >> >> root@...0:~# xl pci-assignable-list >> 0000:02:00.0 >> >> root@...0:~# 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@...0:~# xl pci-list router >> root@...0:~# xl pci-assignable-list >> 0000:00:1b.0 >> 0000:02:00.0 >> >> root@...0:~# 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@...0:~# xl pci-list router >> root@...0:~# xl pci-assignable-list >> 0000:02:00.0 >> >> > And if you do: > # xl pci-detach router 02:00.0 > Do you see it being cleared from pciback? And what do you > see in /sys/bus/pci/drivers/pciback ? Hmm good point .. i also had the plan to look into xenstore what was in there .. but forgot .. will post both right away :-) > Thanks! -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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