From: Marc Zyngier <marc.zyngier@arm.com>
To: Peter Maydell <peter.maydell@linaro.org>
Cc: Christoffer Dall <c.dall@virtualopensystems.com>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"avi@redhat.com" <avi@redhat.com>,
"android-virt@lists.cs.columbia.edu"
<android-virt@lists.cs.columbia.edu>,
"tech@virtualopensystems.com" <tech@virtualopensystems.com>
Subject: Re: [Android-virt] [PATCH v5 00/13] KVM/ARM Implementation
Date: Wed, 01 Feb 2012 13:40:33 +0000 [thread overview]
Message-ID: <4F2940D1.4040505@arm.com> (raw)
In-Reply-To: <CAFEAcA97AOHsDOKsa12_wjDi46MjmfH1qzcFJFcLYLNEAhS+gw@mail.gmail.com>
On 01/02/12 12:20, Peter Maydell wrote:
> On 1 February 2012 12:11, Marc Zyngier <marc.zyngier@arm.com> wrote:
>> The obvious fix would be to test for the virt extensions in ID_PFR1
>> before enabling KVM, and mask out the virt extensions from the same
>> register in the guest by trapping CP15-c0. But c0 is used by cache
>> maintenance operations, and trapping would lead to unacceptable
>> performance degradation.
>
> You can just set HCR.TID3 to get hyp traps on only the feature
> ID registers, right? (traps access to only ID_PFR0, ID_PFR1, ID_DFR0,
> ID_AFR0, ID_MMFR0, ID_MMFR1, ID_MMFR2, ID_MMFR3, ID_ISAR0, ID_ISAR1,
> ID_ISAR2, ID_ISAR3, ID_ISAR4, ID_ISAR5, MVFR0, and MVFR1, none
> of which should be on performance-critical paths I hope.)
Good catch. It looks much better, except that ID_MMFR3 is used in
cpu_v7_set_pte_ext(), which is called each time you map a page. Ouch.
I'm not even sure we can the cache ID_MMFR3 in the kernel (multi-cluster
systems may have different features).
M.
--
Jazz is not dead. It just smells funny...
next prev parent reply other threads:[~2012-02-01 13:40 UTC|newest]
Thread overview: 105+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-11 10:24 [PATCH v5 00/13] KVM/ARM Implementation Christoffer Dall
2011-12-11 10:24 ` [PATCH v5 01/13] ARM: KVM: Initial skeleton to compile KVM support Christoffer Dall
2011-12-11 10:24 ` [PATCH v5 02/13] ARM: KVM: Hypervisor identity mapping Christoffer Dall
2011-12-11 10:24 ` [PATCH v5 03/13] ARM: KVM: Add hypervisor inititalization Christoffer Dall
2011-12-11 10:24 ` [PATCH v5 04/13] ARM: KVM: Memory virtualization setup Christoffer Dall
2011-12-12 14:40 ` Avi Kivity
2011-12-12 15:09 ` [Android-virt] " Christoffer Dall
2011-12-12 15:15 ` Avi Kivity
2011-12-12 15:25 ` Peter Maydell
2011-12-12 15:49 ` Avi Kivity
2011-12-12 17:40 ` Christoffer Dall
2011-12-13 17:10 ` Antonios Motakis
2011-12-13 17:13 ` Christoffer Dall
2011-12-11 10:24 ` [PATCH v5 05/13] ARM: KVM: Inject IRQs and FIQs from userspace Christoffer Dall
2011-12-11 15:18 ` Jan Kiszka
2011-12-11 16:03 ` Peter Maydell
2011-12-11 19:30 ` Christoffer Dall
2011-12-11 19:48 ` Peter Maydell
2011-12-11 20:07 ` [Android-virt] " Christoffer Dall
2011-12-11 20:25 ` Peter Maydell
2011-12-11 21:36 ` Christoffer Dall
2011-12-11 22:12 ` Peter Maydell
2011-12-11 22:35 ` Peter Maydell
2011-12-11 22:53 ` Christoffer Dall
2011-12-11 23:01 ` Jan Kiszka
2011-12-12 16:31 ` Peter Maydell
2011-12-12 17:40 ` Avi Kivity
2011-12-29 1:29 ` Christoffer Dall
2012-02-09 1:15 ` Peter Maydell
2011-12-12 11:06 ` Marc Zyngier
2011-12-12 12:54 ` Christoffer Dall
2011-12-12 6:35 ` Alexander Graf
2011-12-11 19:16 ` Christoffer Dall
2011-12-12 13:28 ` Avi Kivity
2011-12-12 14:38 ` [Android-virt] " Christoffer Dall
2011-12-12 14:50 ` Avi Kivity
2011-12-12 15:11 ` Christoffer Dall
2011-12-12 15:16 ` Avi Kivity
2011-12-11 10:24 ` [PATCH v5 06/13] ARM: KVM: World-switch implementation Christoffer Dall
2011-12-11 10:25 ` [PATCH v5 07/13] ARM: KVM: Emulation framework and CP15 emulation Christoffer Dall
2011-12-12 13:44 ` Avi Kivity
2011-12-12 16:17 ` Christoffer Dall
2011-12-11 10:25 ` [PATCH v5 08/13] ARM: KVM: Handle guest faults in KVM Christoffer Dall
2011-12-12 15:05 ` Avi Kivity
2011-12-12 19:53 ` Christoffer Dall
2011-12-13 9:45 ` Avi Kivity
2011-12-13 13:10 ` [Android-virt] " Christoffer Dall
2011-12-13 13:17 ` Marc Zyngier
2011-12-13 13:23 ` Avi Kivity
2011-12-13 13:44 ` Christoffer Dall
2011-12-13 14:27 ` Avi Kivity
2011-12-11 10:25 ` [PATCH v5 09/13] ARM: KVM: Handle I/O aborts Christoffer Dall
2011-12-12 13:54 ` Avi Kivity
2011-12-12 14:56 ` [Android-virt] " Christoffer Dall
2011-12-11 10:25 ` [PATCH v5 10/13] ARM: KVM: Guest wait-for-interrupts (WFI) support Christoffer Dall
2011-12-12 14:12 ` Avi Kivity
2011-12-12 16:20 ` Christoffer Dall
2011-12-12 17:44 ` Avi Kivity
2011-12-12 19:21 ` [Android-virt] " Christoffer Dall
2011-12-13 9:41 ` Avi Kivity
2011-12-11 10:25 ` [PATCH v5 11/13] ARM: KVM: Support SMP hosts Christoffer Dall
2011-12-12 14:30 ` Avi Kivity
2011-12-12 17:37 ` Christoffer Dall
2011-12-12 17:56 ` Avi Kivity
2011-12-12 19:38 ` [Android-virt] " Christoffer Dall
[not found] ` <CAEDV+gJ=zeDpfp0kS2uBvmgRMyCpsV1LitjKR66R4W9Y3VGgWw@mail.gmail.com>
[not found] ` <4EE71CF1.5080705@redhat.com>
2011-12-13 13:36 ` Christoffer Dall
2011-12-13 14:17 ` Avi Kivity
2011-12-13 14:36 ` Christoffer Dall
2011-12-13 14:17 ` Marc Zyngier
2011-12-19 6:15 ` Antonios Motakis
2011-12-19 14:57 ` [Android-virt] " Christoffer Dall
2011-12-19 15:19 ` Marc Zyngier
2011-12-19 15:30 ` Antonios Motakis
2011-12-19 15:37 ` Marc Zyngier
2011-12-19 15:40 ` Christoffer Dall
2011-12-19 15:42 ` Antonios Motakis
2011-12-19 15:45 ` Marc Zyngier
[not found] ` <CAEDV+gL929Hpa=PncVWeHRNAa5fBuorNNYFC=iix=PO+5aO2cg@mail.gmail.com>
2011-12-19 17:19 ` Peter Maydell
2011-12-19 17:24 ` Christoffer Dall
2011-12-19 17:36 ` Peter Maydell
2011-12-19 17:40 ` Christoffer Dall
2011-12-11 10:25 ` [PATCH v5 12/13] ARM: KVM: Fix guest view of MPIDR Christoffer Dall
2011-12-12 14:32 ` Avi Kivity
2011-12-12 17:39 ` Christoffer Dall
2011-12-12 17:44 ` Marc Zyngier
2011-12-12 19:43 ` Christoffer Dall
2011-12-13 9:46 ` Avi Kivity
2011-12-13 13:38 ` Christoffer Dall
2011-12-11 10:25 ` [PATCH v5 13/13] ARM: KVM: Support SMP guests Christoffer Dall
2011-12-11 11:32 ` [PATCH v5 00/13] KVM/ARM Implementation Peter Maydell
2011-12-11 19:23 ` Christoffer Dall
2011-12-11 19:27 ` Peter Maydell
2012-01-11 16:48 ` Peter Maydell
2012-01-12 3:29 ` Christoffer Dall
2012-01-12 8:19 ` Peter Maydell
2012-01-12 16:15 ` [Android-virt] " Christoffer Dall
2012-01-20 2:59 ` Christoffer Dall
2012-01-30 22:46 ` Peter Maydell
2012-01-30 23:02 ` Alexander Graf
2012-01-31 14:39 ` Antonios Motakis
2012-02-01 12:11 ` Marc Zyngier
2012-02-01 12:20 ` Peter Maydell
2012-02-01 13:40 ` Marc Zyngier [this message]
2012-02-01 13:57 ` Peter Maydell
2012-02-01 13:59 ` Christoffer Dall
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