From: Segher Boessenkool <segher@kernel.crashing.org>
To: Alexander Graf <agraf@suse.de>
Cc: Linuxppc-dev <linuxppc-dev@ozlabs.org>,
Paul Mackerras <paulus@samba.org>, KVM list <kvm@vger.kernel.org>,
kvm-ppc@vger.kernel.org
Subject: Re: [PATCH 10/13] kvm/powerpc: Add support for Book3S processors in hypervisor mode
Date: Sat, 28 May 2011 01:07:04 +0000 [thread overview]
Message-ID: <10cc079a31947ec4b6d39f30f2ac50f2@kernel.crashing.org> (raw)
In-Reply-To: <6A1CA2C8-8032-4D67-9C14-4ABD81ABCDD7@suse.de>
>>> If HDEC expires when interrupts are off, the HDEC interrupt stays
>>> pending until interrupts get re-enabled. I'm not sure exactly what
>>> the conditions are that cause an HDEC interrupt to get lost, but they
>>> seem to involve at least a partition switch.
>>
>> On some CPUs, if the top bit of the decrementer is 0 again when you
>> re-enable
>> the interrupt, the interrupt is lost (so it is actually
>> level-triggered).
>> The arch books talk a bit about this AFAIR.
>
> Sure, but that shouldn't happen with HDEC during the odd 50
> instructions that it takes to enter the guest :)
It's more like 500 insns, including some ptesync, so lots of cycles too.
Can another hardware thread be running at the same time?
Segher
next prev parent reply other threads:[~2011-05-28 1:07 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20110511103443.GA2837@brick.ozlabs.ibm.com>
[not found] ` <20110511104456.GK2837@brick.ozlabs.ibm.com>
2011-05-15 21:58 ` [PATCH 10/13] kvm/powerpc: Add support for Book3S processors in hypervisor mode Alexander Graf
2011-05-16 5:58 ` [PATCH 10/13] kvm/powerpc: Add support for Book3S processors in Paul Mackerras
2011-05-17 10:17 ` [PATCH 10/13] kvm/powerpc: Add support for Book3S processors in hypervisor mode Alexander Graf
2011-05-27 10:33 ` [PATCH 10/13] kvm/powerpc: Add support for Book3S processors in Paul Mackerras
2011-05-27 10:43 ` [PATCH 10/13] kvm/powerpc: Add support for Book3S processors in hypervisor mode Alexander Graf
2011-05-27 20:59 ` Segher Boessenkool
2011-05-27 23:19 ` Alexander Graf
2011-05-28 1:07 ` Segher Boessenkool [this message]
2011-05-31 20:26 ` Jimi Xenidis
2011-05-31 22:34 ` Segher Boessenkool
2011-06-01 5:11 ` [PATCH 10/13] kvm/powerpc: Add support for Book3S processors in Paul Mackerras
[not found] ` <764651B6-6DDA-49DC-AA95-52CD86FF82D9@suse.de>
[not found] ` <20110517111536.GC7924@brick.ozlabs.ibm.com>
[not found] ` <14CFAA70-1747-4902-8CC1-4BE924CAD031@suse.de>
[not found] ` <4DD25F10.4030707@redhat.com>
[not found] ` <20110519052246.GA8165@drongo>
2011-05-19 6:01 ` [PATCH 0/13] Hypervisor-mode KVM on POWER7 Alexander Graf
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