From: "H. Peter Anvin" <hpa@zytor.com>
To: Gleb Natapov <gleb@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
kvm@vger.kernel.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, avi@redhat.com, mingo@elte.hu,
tglx@linutronix.de, riel@redhat.com, cl@linux-foundation.org
Subject: Re: [PATCH v3 04/12] Add "handle page fault" PV helper.
Date: Wed, 20 Jan 2010 09:43:41 -0800 [thread overview]
Message-ID: <4B5740CD.4020005@zytor.com> (raw)
In-Reply-To: <20100120100254.GC5238@redhat.com>
On 01/20/2010 02:02 AM, Gleb Natapov wrote:
>
>> You can have the guest OS take an exception on a vector above 31 just
>> fine; you just need it to tell the hypervisor which vector it, the OS,
>> assigned for this purpose.
>>
> VMX doesn't allow to inject hardware exception with vector greater then 31.
> SDM 3B section 23.2.1.3.
>
OK, you're right. I had missed that... I presume it was done for
implementation reasons.
> I can inject the event as HW interrupt on vector greater then 32 but not
> go through APIC so EOI will not be required. This sounds non-architectural
> and I am not sure kernel has entry point code for this kind of event, it
> has one for exception and one for interrupts that goes through __do_IRQ()
> which assumes that interrupts should be ACKed.
You can also just emulate the state transition -- since you know you're
dealing with a flat protected-mode or long-mode OS (and just make that a
condition of enabling the feature) you don't have to deal with all the
strange combinations of directions that an unrestricted x86 event can
take. Since it's an exception, it is unconditional.
-hpa
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next prev parent reply other threads:[~2010-01-20 17:48 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-05 14:12 [PATCH v3 00/12] KVM: Add host swap event notifications for PV guest Gleb Natapov
2010-01-05 14:12 ` [PATCH v3 01/12] Move kvm_smp_prepare_boot_cpu() from kvmclock.c to kvm.c Gleb Natapov
2010-01-05 14:12 ` [PATCH v3 02/12] Add PV MSR to enable asynchronous page faults delivery Gleb Natapov
2010-01-05 14:12 ` [PATCH v3 03/12] Add async PF initialization to PV guest Gleb Natapov
2010-01-05 14:12 ` [PATCH v3 04/12] Add "handle page fault" PV helper Gleb Natapov
2010-01-14 17:31 ` Peter Zijlstra
2010-01-17 14:44 ` Gleb Natapov
2010-01-17 15:09 ` Peter Zijlstra
2010-01-17 15:12 ` Gleb Natapov
2010-01-18 9:53 ` Andi Kleen
2010-01-18 8:34 ` H. Peter Anvin
2010-01-18 8:50 ` Gleb Natapov
2010-01-19 1:53 ` H. Peter Anvin
2010-01-19 6:55 ` Gleb Natapov
2010-01-19 17:03 ` H. Peter Anvin
2010-01-19 17:44 ` Gleb Natapov
2010-01-19 20:10 ` H. Peter Anvin
2010-01-20 10:02 ` Gleb Natapov
2010-01-20 12:00 ` Avi Kivity
2010-01-20 17:18 ` Rik van Riel
2010-01-21 8:56 ` Avi Kivity
2010-01-20 18:45 ` H. Peter Anvin
2010-01-21 8:58 ` Avi Kivity
2010-01-20 17:43 ` H. Peter Anvin [this message]
2010-01-21 9:02 ` Avi Kivity
2010-01-21 9:04 ` Gleb Natapov
2010-01-21 9:05 ` Avi Kivity
2010-01-21 15:47 ` H. Peter Anvin
2010-01-22 7:25 ` Gleb Natapov
2010-01-05 14:12 ` [PATCH v3 05/12] Export __get_user_pages_fast Gleb Natapov
2010-01-17 15:46 ` Christoph Hellwig
2010-01-05 14:12 ` [PATCH v3 06/12] Add get_user_pages() variant that fails if major fault is required Gleb Natapov
2010-01-17 15:43 ` Christoph Hellwig
2010-01-05 14:12 ` [PATCH v3 07/12] Maintain memslot version number Gleb Natapov
2010-01-05 14:12 ` [PATCH v3 08/12] Inject asynchronous page fault into a guest if page is swapped out Gleb Natapov
2010-01-05 14:12 ` [PATCH v3 09/12] Retry fault before vmentry Gleb Natapov
2010-01-05 14:12 ` [PATCH v3 10/12] Handle async PF in non preemptable context Gleb Natapov
2010-01-05 14:12 ` [PATCH v3 11/12] Let host know whether the guest can handle async PF in non-userspace context Gleb Natapov
2010-01-05 14:12 ` [PATCH v3 12/12] Send async PF when guest is not in userspace too Gleb Natapov
2010-01-05 15:05 ` [PATCH v3 00/12] KVM: Add host swap event notifications for PV guest Jun Koi
2010-01-05 15:59 ` Rik van Riel
2010-01-05 16:04 ` Avi Kivity
2010-01-06 10:17 ` Jun Koi
2010-01-06 10:21 ` Gleb Natapov
2010-01-08 16:18 ` Marcelo Tosatti
2010-01-08 16:47 ` Gleb Natapov
2010-01-08 19:24 ` Rik van Riel
2010-01-08 19:30 ` Bryan Donlan
2010-01-08 19:55 ` Rik van Riel
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