[dpdk-dev] [dpdk-stable] [PATCH v2] igb_uio: prevent reset for a list of devices

[Chas Williams]

I will confess I haven't looked into the issue too hard since I have a
workaround.  My first guess is that there is something going on with the
IOMMU and quiescing a PCI pass-through device/function from the guest
(since I don't think the IOMMU is "visible" to the guest) seems iffy.

Most devices have some sort of reset to put the device into a known state
for setup/configuration (or enable/disable for the DMA engines).  If this
is done at .dev_close(), shouldn't that be as sufficient as resetting the
function?

On Tue, Nov 7, 2017 at 1:49 PM, Ferruh Yigit <ferruh.yigit at intel.com> wrote:

> On 11/7/2017 10:12 AM, Chas Williams wrote:
> > Environment: Dell PowerEdge R730, Intel Corporation 82599ES 10-Gigabit
> SFI/SFP+
> > Network Connection shared via PCI pass-through
> > Host: Debian 8
> > Guest: Custom Debian 8 with DPDK application based on 17.11
> >
> > When we shutdown the guest, the kernel panics with:
> >
> > [  279.021818] Do you have a strange power saving mode enabled?
> > [  279.021819] Dazed and confused, but trying to continue
> > [  279.021847] {1}[Hardware Error]: Hardware error from APEI Generic
> Hardware
> > Error Source: 3
> > [  279.021849] {1}[Hardware Error]: event severity: fatal
> > [  279.021850] {1}[Hardware Error]:  Error 0, type: fatal
> > [  279.021851] {1}[Hardware Error]:   section_type: PCIe error
> > [  279.021852] {1}[Hardware Error]:   port_type: 0, PCIe end point
> > [  279.021853] {1}[Hardware Error]:   version: 1.16
> > [  279.021854] {1}[Hardware Error]:   command: 0x0507, status: 0x4010
> > [  279.021855] {1}[Hardware Error]:   device_id: 0000:03:00.0
> > [  279.021855] {1}[Hardware Error]:   slot: 0
> > [  279.021856] {1}[Hardware Error]:   secondary_bus: 0x00
> > [  279.021857] {1}[Hardware Error]:   vendor_id: 0x8086, device_id:
> 0x10fb
> > [  279.021858] {1}[Hardware Error]:   class_code: 000002
> > [  279.021859] Kernel panic - not syncing: Fatal hardware error!
> > [  279.021977] sched: Unexpected reschedule of offline CPU#1!
> > [  279.021984] ------------[ cut here ]------------
> > [  279.021992] WARNING: CPU: 43 PID: 2807 at
> > /build/linux-fHlJSJ/linux-4.12.6/arch/x86/kernel/smp.c:128
> > native_smp_send_reschedule+0x34/0x40
> > [  279.021993] Modules linked in: vfio_pci vfio_virqfd vfio_iommu_type1
> vfio
> > openvswitch nf_conntrack_ipv6 nf_nat_ipv6 nf_conntrack_ipv4
> nf_defrag_ipv4
> > nf_nat_ipv4 nf_defrag_ipv6 nf_nat nf_conntrack libcrc32c crc32c_generic
> nfsd
> > nfs_aclr
> > pcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace sunrpc
> fscache tun
> > intel_rapl sb_edac x86_pkg_temp_thermal intel_powerclamp coretemp
> kvm_intel kvm
> > irqbypass mgag200 ttm drm_kms_helper drm joydev crct10dif_pclmul
> crc32_pclmu
> > l ghash_clmulni_intel i2c_algo_bit ipmi_si ipmi_devintf iTCO_wdt
> intel_cstate
> > iTCO_vendor_support evdev intel_uncore mxm_wmi lpc_ich ipmi_msghandler
> mfd_core
> > ioatdma intel_rapl_perf dcdbas pcspkr shpchp mei_me button wmi mei
> acpi_power_m
> > eter tpm_crb autofs4 ext4 crc16 jbd2 fscrypto mbcache sr_mod cdrom sg
> > hid_generic usbhid hid sd_mod
> > [  279.022044]  crc32c_intel aesni_intel aes_x86_64 crypto_simd cryptd
> > glue_helper ahci ehci_pci libahci ehci_hcd ixgbe libata megaraid_sas
> usbcore dca
> > i40e usb_common ptp pps_core scsi_mod mdio
> > [  279.022060] CPU: 43 PID: 2807 Comm: revalidator85 Not tainted
> 4.12.0-1-amd64
> > #1 Debian 4.12.6-1
> > [  279.022061] Hardware name: Dell Inc. PowerEdge R730/0WCJNT, BIOS
> 2.3.4 11/08/2016
> > [  279.022062] task: ffff91d0473f7100 task.stack: ffffafef8f4a4000
> > [  279.022066] RIP: 0010:native_smp_send_reschedule+0x34/0x40
> > [  279.022067] RSP: 0018:ffffafef8f4a7c98 EFLAGS: 00010082
> > [  279.022069] RAX: 000000000000002e RBX: ffff91d059d24080 RCX:
> 0000000000000001
> > [  279.022070] RDX: 0000000000000000 RSI: 0000000000000002 RDI:
> 0000000000000046
> > [  279.022071] RBP: ffff91d04691d100 R08: 0000000000000000 R09:
> 000000000000002e
> > [  279.022072] R10: ffffafef8f4a7c90 R11: 00000000001cbb78 R12:
> ffff91d85d21ae80
> > [  279.022073] R13: ffff91d059d24000 R14: 0000000000000002 R15:
> 0000000000000008
> > [  279.022075] FS:  00007f726affd700(0000) GS:ffff91d85d740000(0000)
> > knlGS:0000000000000000
> > [  279.022076] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > [  279.022077] CR2: 00007fd422a52c48 CR3: 000000042d90f000 CR4:
> 00000000003426e0
> > [  279.022078] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
> 0000000000000000
> > [  279.022079] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7:
> 0000000000000400
> > [  279.022080] Call Trace:
> > [  279.022086]  ? check_preempt_wakeup+0x181/0x220
> > [  279.022091]  ? check_preempt_curr+0x74/0x80
> > [  279.022094]  ? ttwu_do_wakeup+0x19/0x140
> > [  279.022098]  ? try_to_wake_up+0x1b8/0x470
> > [  279.022101]  ? wake_up_q+0x3f/0x70
> > [  279.022106]  ? futex_wake+0x15a/0x170
> > [  279.022108]  ? do_futex+0x2df/0xa90
> > [  279.022111]  ? SyS_futex+0x7a/0x170
> > [  279.022113]  ? SyS_read+0x76/0xc0
> > [  279.022118]  ? system_call_fast_compare_end+0xc/0x97
> > [  279.022119] Code: a3 05 51 fb cc 00 73 15 48 8b 05 28 74 a3 00 be fd
> 00 00 00
> > 48 8b 80 a0 00 00 00 ff e0 89 fe 48 c7 c7 88 5c de b6 e8 e2 c9 13 00
> <0f> ff c3
> > 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 8b 05 5d 00
> > [  279.022151] ---[ end trace eddc980dc8648163 ]---
> > [  279.454274] Kernel Offset: 0x35400000 from 0xffffffff81000000
> (relocation
> > range: 0xffffffff80000000-0xffffffffbfffffff)
> >
> > The test engineer says this doesn't happen if we use SRIOV (which makes
> sense
> > since the device isn't directly shared between the guest and the host).
> If I
> > remove the pci_reset_function() from igb_uio's .release, then all is
> well.
>
> This was tougher than expected, so many unexpected behavior. Why resetting
> pass-through device in guest cause a crash in the host?
>
> Finally, I will send a patch to remove the reset. Hopefully no more
> surprises
> for release.
>
> Still there will remain two improvement in igb_uio for better security,
> disabling device interrupt on exit and clear master on exit.
>
> >
> >
> > On Tue, Nov 7, 2017 at 8:02 AM, Thomas Monjalon <thomas at monjalon.net
> > <mailto:thomas at monjalon.net>> wrote:
> >
> >     07/11/2017 12:50, Chas Williams:
> >     > We still have an issue with this and PCI pass-through.  If a guest
> is
> >     > restarted while using PCI pass-through and igb_uio issues a
> >     > pci_reset_function(), this causes the host to crash.
> >
> >     Please, could you better explain the exact scenario and the cause of
> the crash?
> >     Thanks
> >
> >
>
>