From: "Radim Krčmář" <rkrcmar@redhat.com>
To: Eduardo Habkost <ehabkost@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>,
Paolo Bonzini <pbonzini@redhat.com>,
peterx@redhat.com, Andrew Jones <drjones@redhat.com>,
kvm@vger.kernel.org
Subject: Re: kvm_pv_unhalt and kernel_irqchip=off
Date: Wed, 10 Aug 2016 21:04:13 +0200 [thread overview]
Message-ID: <20160810190412.GA8001@potion> (raw)
In-Reply-To: <20160810182704.GE5627@thinpad.lan.raisama.net>
2016-08-10 15:27-0300, Eduardo Habkost:
> Hi,
>
> I got a bug report[1] that seems to be caused by kvm_pv_unhalt
> not working with kernel_irqchip=off.
>
> Is kvm_pv_unhalt supposed to work at all without kernel_irqchip?
No. Guest interface of current PV unhalt is based on APIC ID and KVM
does not ask userspace to handle the unknown mapping to VCPU.
The code in kernel just somehow managed not to BUG. :)
> Should QEMU prevent it from being enabled if kernel_irqchip=off?
Yes. We'd need a new guest or userspace interface to make it work.
KVM should not pretend that the feature works without kernel_irqchip.
> Related question: is there any kvm-unit-test test for
> kvm_pv_unhalt?
Not that I know of, thanks for the request.
> [1] https://bugzilla.redhat.com/show_bug.cgi?id=1363679
next prev parent reply other threads:[~2016-08-10 19:04 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-10 18:27 kvm_pv_unhalt and kernel_irqchip=off Eduardo Habkost
2016-08-10 19:04 ` Radim Krčmář [this message]
2016-08-10 20:58 ` Radim Krčmář
2016-08-12 18:37 ` GET_SUPPORTED_CPUID and irqchip (was Re: kvm_pv_unhalt and kernel_irqchip=off) Eduardo Habkost
2016-08-13 12:43 ` Radim Krčmář
2016-08-15 13:03 ` Eduardo Habkost
2016-08-15 13:21 ` Paolo Bonzini
2016-08-15 17:50 ` Radim Krčmář
2016-08-15 18:00 ` Eduardo Habkost
2016-08-15 18:32 ` Radim Krčmář
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