From: Antonios Motakis <a.motakis@virtualopensystems.com>
To: Marc Zyngier <marc.zyngier@arm.com>
Cc: c.dall@virtualopensystems.com,
android-virt@lists.cs.columbia.edu, kvm@vger.kernel.org
Subject: Re: [Android-virt] [PATCH RFC v2 3/3] ARM: KVM: Add support for MMU notifiers
Date: Sat, 11 Feb 2012 16:00:56 +0100 [thread overview]
Message-ID: <4F3682A8.2060006@virtualopensystems.com> (raw)
In-Reply-To: <1328912534-28888-3-git-send-email-marc.zyngier@arm.com>
On 02/10/2012 11:22 PM, Marc Zyngier wrote:
> +ENTRY(__kvm_tlb_flush_vmid)
> + hvc #0 @ Switch to Hyp mode
> + push {r2, r3}
>
> + ldrd r2, r3, [r0, #KVM_VTTBR]
> + mcrr p15, 6, r2, r3, c2 @ Write VTTBR
> + isb
> + mcr p15, 0, r0, c8, c7, 0 @ TBLIALL
> + dsb
> + isb
> + mov r2, #0
> + mov r3, #0
> + mcrr p15, 6, r2, r3, c2 @ Back to VMID #0
> + isb
> +
> + pop {r2, r3}
> + hvc #0 @ Back to SVC
> + mov pc, lr
> +ENDPROC(__kvm_tlb_flush_vmid)
With the last VMID implementation, you could get the equivalent effect
of a per-VMID flush, by just getting a new VMID for the current VM. So
you could do a (kvm->arch.vmid = 0) to force a new VMID when the guest
reruns, and save the overhead of that flush (you will do a complete
flush every 255 times instead of a small one every single time).
Best regards,
Antonios
next prev parent reply other threads:[~2012-02-11 15:01 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-10 22:22 [PATCH RFC v2 1/3] KVM: Guard mmu_notifier specific code with CONFIG_MMU_NOTIFIER Marc Zyngier
2012-02-10 22:22 ` [PATCH RFC v2 2/3] ARM: KVM: mark the end of the HYP mode code with __kvm_hyp_code_end Marc Zyngier
2012-02-10 22:32 ` Christoffer Dall
2012-02-10 22:22 ` [PATCH RFC v2 3/3] ARM: KVM: Add support for MMU notifiers Marc Zyngier
2012-02-10 22:49 ` Christoffer Dall
2012-02-11 15:00 ` Antonios Motakis [this message]
2012-02-11 17:35 ` [Android-virt] " Christoffer Dall
2012-02-11 18:33 ` Antonios Motakis
2012-02-12 1:12 ` Christoffer Dall
2012-02-12 8:20 ` Alexander Graf
2012-02-13 13:13 ` Marc Zyngier
2012-02-13 14:50 ` Christoffer Dall
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