From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcelo Tosatti Subject: Re: [PATCH 0/4] Unlocked TLB flush Date: Mon, 7 May 2012 22:25:34 -0300 Message-ID: <20120508012534.GA26243@amt.cnet> References: <1336044182-12023-1-git-send-email-avi@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: kvm@vger.kernel.org, Xiao Guangrong , takuya.yoshikawa@gmail.com To: Avi Kivity Return-path: Received: from mx1.redhat.com ([209.132.183.28]:50966 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757891Ab2EHC3u (ORCPT ); Mon, 7 May 2012 22:29:50 -0400 Content-Disposition: inline In-Reply-To: <1336044182-12023-1-git-send-email-avi@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On Thu, May 03, 2012 at 02:22:58PM +0300, Avi Kivity wrote: > This patchset implements unlocked TLB flushing for KVM. An operation that > generates stale TLB entries can mark the TLB as dirty instead of flushing > immediately, and then flush after releasing mmu_lock but before returning > to the guest or the caller. A few call sites are converted too. > > Note not all call sites are easily convertible; as an example, sync_page() > must flush before reading the guest page table. Huh? Are you referring to: * Note: * We should flush all tlbs if spte is dropped even though guest is * responsible for it. Since if we don't, * kvm_mmu_notifier_invalidate_page * and kvm_mmu_notifier_invalidate_range_start detect the mapping page * isn't * used by guest then tlbs are not flushed, so guest is allowed to * access the * freed pages. * And we increase kvm->tlbs_dirty to delay tlbs flush in this case. With an increased dirtied_count the flush can be performed by kvm_mmu_notifier_invalidate_page.