Re: Qemu e1000 broken in -rc1 and -rc2 : bisected

[Chen, Tiejun]

On 2015/3/7 3:27, Ken Moffat wrote:
> On Fri, Mar 06, 2015 at 12:02:40AM +0000, Ken Moffat wrote:
> >   I have a very recent qemu i686 image, using a 3.19.0 kernel and
> > dhclient, which works fine if the host is running a 3.19.0 kernel,
> > but breaks when the host runs 4.0.0-rc1 or -rc2.
> >
> >   On those, dhclient does not get an address, so I have no network.
> > There is a message
> > e1000 0000:00:03.0 eth0: Reset adaptor
> >
> >   Before I start trying to bisect this, has anybody already seen, or
> > fixed, it ?
>   Bisected.
> b4eef9b36db461ca44832226fbca614db58c0c33 is the first bad commit
> commit b4eef9b36db461ca44832226fbca614db58c0c33
> Author: Tiejun Chen <tiejun.chen@xxxxxxxxx>
> Date:   Mon Dec 22 10:32:57 2014 +0100
>
>      kvm: x86: vmx: NULL out hwapic_isr_update() in case of
> !enable_apicv
>
>      In most cases calling hwapic_isr_update(), we always check if
>      kvm_apic_vid_enabled() == 1, but actually,
>      kvm_apic_vid_enabled()
>          -> kvm_x86_ops->vm_has_apicv()
>              -> vmx_vm_has_apicv() or '0' in svm case
>                  -> return enable_apicv && irqchip_in_kernel(kvm)
>
>      So its a little cost to recall vmx_vm_has_apicv() inside
>      hwapic_isr_update(), here just NULL out hwapic_isr_update() in
>      case of !enable_apicv inside hardware_setup() then make all
>      related stuffs follow this. Note we don't check this under that
>      condition of irqchip_in_kernel() since we should make sure
>      definitely any caller don't work  without in-kernel irqchip.
>
>      Signed-off-by: Tiejun Chen <tiejun.chen@xxxxxxxxx>
>      Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
>
>   I have reverted this from -rc2 (big offsets, 209 and 357 lines) and
> everything is working again.

Did you try Linux 4.0-rc3? That includes one relevant fix,

KVM: SVM: fix interrupt injection (apic->isr_count always 0)

Thanks
Tiejun
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