Xen project Mailing List

Re: [Xen-devel] MSI causing softpanics in guest

To: "Shan, Haitao" <haitao.shan@xxxxxxxxx>

From: Anish Bhatt <anish@xxxxxxxxxxxxx>

Date: Tue, 23 Sep 2008 20:07:56 -0400

Cc: "xen-devel@xxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxx>, Keir Fraser <keir.fraser@xxxxxxxxxxxxx>

Delivery-date: Tue, 23 Sep 2008 17:08:24 -0700

List-id: Xen developer discussion <xen-devel.lists.xensource.com>

No, the bug_on is not triggered in dom0. I also saw the following error message in xm dmesg, : /physdev.c:90:d0 remap pirq fa vector 49 while not unmap/ Its part of the code added for MSI, I wonder if its of any significance. -Anish Shan, Haitao wrote: > Just some thoughts on Anish's problem. It seems he reveals a bug in current > code, I think. > > Currently, evnchn_map_pirq is hooked on msi_map_vector > (pci_enable_msi->msi_capability_init->msi_map_vector). Here the pirq type is > set to IRQT_PIRQ. Then request_irq should succeed since pirq type is already > set. > > However, this path only works on the assumption that msi_map_vector and > request_irq are executed in the same domain, to be more specific, dom0. > For PV domU guest, there is no msi_map_vector in its pci_enable_msi ( PV domU > actually asks dom0 to do the msi map, instead. This is a decision made by > Keir and Yunhong long ago. I think it is base on security considerations). So > its irq type is not set correctly (What's more, it incorrectly sets the > dom0's irq type). Then request_irq can trigger this bug_on(). > > Anish, if you use the device in dom0 itself, does it also have this bug_on? > > Keir and Jan, > Do you think this explanation is reasonable for issues Anish met? > > Best Regards > Shan Haitao > > -----Original Message----- > From: Jan Beulich [mailto:jbeulich@xxxxxxxxxx] > Sent: 2008年9月23日 15:24 > To: Anish Bhatt > Cc: Keir Fraser; Shan, Haitao; xen-devel@xxxxxxxxxxxxxxxxxxx > Subject: Re: [Xen-devel] MSI causing softpanics in guest > > So the question is what irq you pass in to request_irq() and where you got > it from. Jan > > >>>> Anish Bhatt <anish@xxxxxxxxxx> 23.09.08 07:04 >>> >>>> > I put a printk before BUG_ON, Its expecting IRQT_PIRQ, but getting > IRQT_UNBOUND instead. > -Anish > > Jan Beulich wrote: > >>>>> Keir Fraser <keir.fraser@xxxxxxxxxxxxx> 20.09.08 10:15 >>> >>>>> >>>>> >>> On 3.3.0 you need to specify msi=1 on Xen's command line to enable MSI. In >>> xen-unstable, MSI support is always enabled. >>> >>> I changed a check in evtchn_get_xen_pirq() into a BUG_ON() as it looks to me >>> like it should never trigger. Jan Beulich was the original authour of that >>> function -- cc'ed in case he can indicate whether I've actually broken the >>> function. :-) >>> >>> >> No, I think that BUG_ON() you added is valid. It definitely is in the context >> of startup_pirq(). I'd be curious to know what the type of that irq really >> is, >> but that cannot be determined from the backtrace alone. Anish, could you >> perhaps add a simple printk() before the BUG_ON()? Unfortunately the >> driver in question does not appear to be part of the tree, so we can't even >> check what it does prior to calling request_irq()... >> >> -- Keir >> >> On 19/9/08 20:53, "Anish Bhatt" <anish@xxxxxxxxxxxxx> wrote: >> >> >> >>> lspci shows MSI enabled for PCI device. PCI passthrough works fine. >>> However, as soon as the MSI driver for card is insmodded, kernel panics. >>> This is on xen-unstable. Tried the same with xen-3.3.0 which is >>> supposed to have MSI passthrough, but the same guest shows MSI as disabled. >>> Any else seen this bug, or know of a workaround ? >>> >>> Trace is as follows : >>> >>> ------------[ cut here ]------------ >>> kernel BUG at >>> >>> >>> >> /usr/src/xen/xen-unstable.hg/linux-2.6.18-xen.hg/drivers/xen/core/evtchn.c:809> >> ! >> >> >>> invalid opcode: 0000 [#1] >>> SMP >>> Modules linked in: nfemsg nfdvnet ipv6 binfmt_misc dm_mod nfe usbcore >>> ext3 jbd processor fuse >>> CPU: 0 >>> EIP: 0061:[<c02487f5>] Tainted: GF VLI >>> EFLAGS: 00210097 (2.6.18.8-xen #2) >>> EIP is at evtchn_get_xen_pirq+0x35/0x40 >>> eax: ffffffff ebx: 00000002 ecx: c0372e60 edx: 00000000 >>> esi: c2103560 edi: c03d3080 ebp: 000004f9 esp: ed385dac >>> ds: 007b es: 007b ss: 0069 >>> Process modprobe (pid: 2590, ti=ed384000 task=ed7b1100 task.ti=ed384000) >>> Stack: c0248aef 00000000 00000000 00000000 00000000 00000000 00000000 >>> 00000000 >>> 00000000 00000000 00000000 00000000 00000000 00000000 00000000 >>> 00000000 >>> 00000000 00000000 00000000 00000000 00000000 00000000 00000000 >>> 00000000 >>> Call Trace: >>> [<c0248aef>] startup_pirq+0x3f/0x250 >>> [<c0150b50>] setup_irq+0x160/0x1b0 >>> [<ee0dd270>] nfe_interrupt_handler+0x0/0x30 [nfemsg] >>> [<c0150c43>] request_irq+0xa3/0xc0 >>> [<ee02c8ad>] nfemsg_module_init+0x8ad/0x133e [nfemsg] >>> [<c030531b>] cond_resched+0x2b/0x40 >>> [<c0305369>] wait_for_completion+0x19/0xf0 >>> [<c0142818>] sys_init_module+0x148/0x1b50 >>> [<c010595f>] syscall_call+0x7/0xb >>> Code: 00 00 89 d1 d3 e0 85 05 c4 2c 42 c0 74 1a 8b 14 95 c0 c0 44 c0 89 >>> d0 c1 e8 1c 83 e8 01 75 0c c1 ea 0c 81 e2 ff ff 00 00 89 d0 c3 <0f> 0b >>> 29 03 a4 f1 32 c0 eb ea 90 83 ec 08 89 74 24 04 89 c6 a1 >>> EIP: [<c02487f5>] evtchn_get_xen_pirq+0x35/0x40 SS:ESP 0069:ed385dac >>> ### card [0] start: host progs ### >>> -bash-3.2# >>> Message from syslogd@drake at Sep 19 15:36:44 ... >>> kernel: ------------[ cut here ]------------ >>> >>> Message from syslogd@drake at Sep 19 15:36:44 ... >>> kernel: kernel BUG at >>> >>> >>> >> /usr/src/xen/xen-unstable.hg/linux-2.6.18-xen.hg/drivers/xen/core/evtchn.c:809> >> ! >> >> >>> Message from syslogd@drake at Sep 19 15:36:44 ... >>> kernel: invalid opcode: 0000 [#1] >>> >>> Message from syslogd@drake at Sep 19 15:36:44 ... >>> kernel: SMP >>> >>> Message from syslogd@drake at Sep 19 15:36:44 ... >>> kernel: CPU: 0 >>> >>> Message from syslogd@drake at Sep 19 15:36:44 ... >>> kernel: EIP is at evtchn_get_xen_pirq+0x35/0x40 >>> >>> Message from syslogd@drake at Sep 19 15:36:44 ... >>> kernel: eax: ffffffff ebx: 00000002 ecx: c0372e60 edx: 00000000 >>> >>> Message from syslogd@drake at Sep 19 15:36:44 ... >>> kernel: esi: c2103560 edi: c03d3080 ebp: 000004f9 esp: ed385dac >>> >>> Message from syslogd@drake at Sep 19 15:36:44 ... >>> kernel: ds: 007b es: 007b ss: 0069 >>> >>> Message from syslogd@drake at Sep 19 15:36:44 ... >>> kernel: Process modprobe (pid: 2590, ti=ed384000 task=ed7b1100 >>> task.ti=ed384000) >>> >>> Message from syslogd@drake at Sep 19 15:36:44 ... >>> kernel: Stack: c0248aef 00000000 00000000 00000000 00000000 00000000 >>> 00000000 00000000 >>> >>> Message from syslogd@drake at Sep 19 15:36:44 ... >>> kernel: 00000000 00000000 00000000 00000000 00000000 00000000 >>> 00000000 00000000 >>> >>> Message from syslogd@drake at Sep 19 15:36:44 ... >>> kernel: 00000000 00000000 00000000 00000000 00000000 00000000 >>> 00000000 00000000 >>> >>> Message from syslogd@drake at Sep 19 15:36:44 ... >>> kernel: Call Trace: >>> >>> Message from syslogd@drake at Sep 19 15:36:44 ... >>> kernel: Code: 00 00 89 d1 d3 e0 85 05 c4 2c 42 c0 74 1a 8b 14 95 c0 c0 >>> 44 c0 89 d0 c1 e8 1c 83 e8 01 75 0c c1 ea 0c 81 e2 ff ff 00 00 89 d0 c3 >>> <0f> 0b 29 03 a4 f1 32 c0 eb ea 90 83 ec 08 89 74 24 04 89 c6 a1 >>> >>> Message from syslogd@drake at Sep 19 15:36:44 ... >>> kernel: EIP: [<c02487f5>] evtchn_get_xen_pirq+0x35/0x40 SS:ESP >>> 0069:ed385dac >>> >>> >> >> > > > -- > As long as the music's loud enough, we won't hear the world falling apart. > > > _______________________________________________ > Xen-devel mailing list > Xen-devel@xxxxxxxxxxxxxxxxxxx > http://lists.xensource.com/xen-devel > -- As long as the music's loud enough, we won't hear the world falling apart. _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-devel

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