Re: virtio_net sometimes didn't work

["Michael S. Tsirkin" <mst@redhat.com>]

On Wed, Feb 16, 2011 at 09:53:25AM +0800, lidong chen wrote:
> because of some other work, i could not focus on this problem last month.
> 
> now i find the wrong vaule of isr cause this problem.
> in function vp_interrupt, the isr is 0, and the virtio_balloon pci
> device have 100000 times initerrupts. then IRQ #11 disabled.
> 
> static irqreturn_t vp_interrupt(int irq, void *opaque)
> {
> 	struct virtio_pci_device *vp_dev = opaque;
> 	struct virtio_pci_vq_info *info;
> 	irqreturn_t ret = IRQ_NONE;
> 	unsigned long flags;
> 	u8 isr;
> 
> 	/* reading the ISR has the effect of also clearing it so it's very
> 	 * important to save off the value. */
> 	isr = ioread8(vp_dev->ioaddr + VIRTIO_PCI_ISR);
> 
> 	/* It's definitely not us if the ISR was not high */
> 	if (!isr)
> 		return IRQ_NONE;   //return from here
> 

This implies that io addr values got swapped between the
devices. Try lspci -vv in guest and info pci in qemu and compare
the io address values.

> 
> 
> 2010/12/9 Michael S. Tsirkin <mst@redhat.com>:
> > On Fri, Nov 26, 2010 at 10:38:33AM +0800, lidong chen wrote:
> >> Does this message appear on boot, or after some stress?
> >> on boot, and only appear when boot from network.
> >>
> >> Which qemu-kvm version?
> >> [root@kvm-4slot ~]# /usr/libexec/qemu-kvm --version
> >> QEMU PC emulator version 0.12.1 (qemu-kvm-0.12.1.2), Copyright (c)
> >> 2003-2008 Fabrice Bellard
> >
> > what happens with the latest qemu?
> >
> >> Does cherry-picking 3fff0179e33cd7d0a688dab65700c46ad089e934 help?
> >> the virtio_pci have already used this patch, still have this problem.
> >>
> >> What does info irqs show in qemu?
> >> how to collect this information?
> >>
> >> but I found if modify the slot number of balloon device from 0x03 to
> >> 0x09, the problem solved.
> >>
> >>     <memballoon model='virtio'>
> >>       <alias name='balloon0'/>
> >>       <address type='pci' domain='0x0000' bus='0x00' slot='0x09'
> >> function='0x0'/>
> >>     </memballoon>
> >
> > Interesting. Is it possible that even after baloon is moved,
> > there's still the message in guest, only this time
> > things keep going afterwards?
> >
> >> and i found someone else also meet this problem.
> >> https://bugs.launchpad.net/ubuntu/+source/linux/+bug/584675
> >>
> >>
> >>
> >> 2010/11/25 Michael S. Tsirkin <mst@redhat.com>:
> >> > On Thu, Nov 25, 2010 at 10:21:24PM +0800, lidong chen wrote:
> >> >> [version]
> >> >> the host os version is 2.6.32
> >> >
> >> > Which qemu-kvm version?
> >> >
> >> >> the guest os version is 2.6.16
> >> >>
> >> >> [dmesg]
> >> >> ACPI: (supports S3 S4 S5)
> >> >> Freeing unused kernel memory: 200k freed
> >> >> input: ImExPS/2 Generic Explorer Mouse as /class/input/input2
> >> >> ACPI: PCI Interrupt Link [LNKC] enabled at IRQ 11
> >> >> ACPI: PCI Interrupt 0000:00:03.0[A] -> Link [LNKC] -> GSI 11 (level,
> >> >> high) -> IRQ 11
> >> >> io address 0001c040ACPI: PCI Interrupt Link [LNKD] enabled at IRQ 10
> >> >> ACPI: PCI Interrupt 0000:00:04.0[A] -> Link [LNKD] -> GSI 10 (level,
> >> >> high) -> IRQ 10
> >> >> io address 0001c060ACPI: PCI Interrupt Link [LNKA] enabled at IRQ 10
> >> >> ACPI: PCI Interrupt 0000:00:05.0[A] -> Link [LNKA] -> GSI 10 (level,
> >> >> high) -> IRQ 10
> >> >> io address 0001c080ACPI: PCI Interrupt Link [LNKB] enabled at IRQ 11
> >> >> ACPI: PCI Interrupt 0000:00:06.0[A] -> Link [LNKB] -> GSI 11 (level,
> >> >> high) -> IRQ 11
> >> >> io address 0001c0a0<6>ACPI: PCI Interrupt 0000:00:07.0[A] -> Link
> >> >> [LNKC] -> GSI 11 (level, high) -> IRQ 11
> >> >> io address 0001c0c0<6>ACPI: PCI Interrupt 0000:00:08.0[A] -> Link
> >> >> [LNKD] -> GSI 10 (level, high) -> IRQ 10
> >> >> io address 0001c0e0
> >> >> irq 11: nobody cared (try booting with the "irqpoll" option)
> >> >>  [<c01457b0>] __report_bad_irq+0x2b/0x69
> >> >>  [<c0145979>] note_interrupt+0x18b/0x1b2
> >> >>  [<c01452a9>] handle_IRQ_event+0x26/0x51
> >> >>  [<c014537f>] __do_IRQ+0xab/0xdc
> >> >>  [<c0106445>] do_IRQ+0x46/0x53
> >> >>  [<c0104e8a>] common_interrupt+0x1a/0x20
> >> >>  [<c01276f2>] __do_softirq+0x4f/0xc2
> >> >>  [<c0127793>] do_softirq+0x2e/0x32
> >> >>  [<c0104f3c>] apic_timer_interrupt+0x1c/0x30
> >> >>  [<c0102d55>] default_idle+0x2e/0x5c
> >> >>  [<c0102e14>] cpu_idle+0x91/0xad
> >> >>  [<c03946e5>] start_kernel+0x34c/0x353
> >> >> handlers:
> >> >> [<f88252ee>] (vp_interrupt+0x0/0x3e [virtio_pci])
> >> >> Disabling IRQ #11
> >> >
> >> > Does this message appear on boot, or after some stress?
> >> > Does cherry-picking 3fff0179e33cd7d0a688dab65700c46ad089e934 help?
> >> > Happens with a newer kernel as guest?
> >> > What does info irqs show in qemu?
> >> >
> >> >
> >> > --
> >> > MST
> >> > --
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> >> >
> >