From mboxrd@z Thu Jan 1 00:00:00 1970 From: Takuya Yoshikawa Date: Thu, 21 Jun 2012 13:41:59 +0000 Subject: Re: [PATCH 3/4] KVM: MMU: Make kvm_handle_hva() handle range of addresses Message-Id: <20120621224159.48ce3575e1834d3bdb643fb9@gmail.com> List-Id: References: <20120615203007.4f61bb17.yoshikawa.takuya@oss.ntt.co.jp> <20120615203230.2c577652.yoshikawa.takuya@oss.ntt.co.jp> <4FDF1AFE.4000607@redhat.com> <20120619224648.bbb360c6eeae9887de7b1f93@gmail.com> <4FE2DA5B.4080706@redhat.com> In-Reply-To: <4FE2DA5B.4080706@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Avi Kivity Cc: Takuya Yoshikawa , mtosatti@redhat.com, agraf@suse.de, paulus@samba.org, aarcange@redhat.com, kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, linux-kernel@vger.kernel.org I should have read this before sending v2... On Thu, 21 Jun 2012 11:24:59 +0300 Avi Kivity wrote: > > 1. Separate rmap_pde from lpage_info->write_count and > > make this a simple array. (I once tried this.) > > > > This has the potential to increase cache misses, but I don't think it's > a killer. The separation can simplify other things as well. Yes, I think so too. IIRC, write_count and rmap_pde are not used together so often. > > 2. Use gfn_to_index() and loop over rmap array: ... > > /* main part */ > > for each level { > > rmapp = __gfn_to_rmap(gfn_start, level, memslot); > > for (idx = gfn_to_index(gfn_start, memslot->base_gfn, level); > > idx < gfn_to_index(gfn_end, memslot->base_gfn, level); idx++) { > > ... > > /* loop over rmap array */ > > ret |= handler(kvm, rmapp + idx, data); > > } > > } > > > > Probably want idx <= gfn_to_index(gfn_end-1, ...) otherwise we fail on > small slots. I was thinking the same thing when making v2. But I will check the boundary condition again. (mmu_notifier + memslot + lpage + rmap...) * alignment... Very confusing. Thanks, Takuya