From patchwork Thu Oct 31 21:18:11 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Graf X-Patchwork-Id: 287655 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 8B0E02C038B for ; Fri, 1 Nov 2013 08:21:02 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754425Ab3JaVU6 (ORCPT ); Thu, 31 Oct 2013 17:20:58 -0400 Received: from cantor2.suse.de ([195.135.220.15]:54376 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755374Ab3JaVSo (ORCPT ); Thu, 31 Oct 2013 17:18:44 -0400 Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id D3010A611F; Thu, 31 Oct 2013 22:18:40 +0100 (CET) From: Alexander Graf To: "kvm@vger.kernel.org mailing list" Cc: kvm-ppc@vger.kernel.org, Gleb Natapov , Paolo Bonzini , Paul Mackerras Subject: [PULL 26/51] KVM: PPC: Book3S PR: Reduce number of shadow PTEs invalidated by MMU notifiers Date: Thu, 31 Oct 2013 22:18:11 +0100 Message-Id: <1383254316-11243-27-git-send-email-agraf@suse.de> X-Mailer: git-send-email 1.7.12.4 In-Reply-To: <1383254316-11243-1-git-send-email-agraf@suse.de> References: <1383254316-11243-1-git-send-email-agraf@suse.de> Sender: kvm-ppc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm-ppc@vger.kernel.org From: Paul Mackerras Currently, whenever any of the MMU notifier callbacks get called, we invalidate all the shadow PTEs. This is inefficient because it means that we typically then get a lot of DSIs and ISIs in the guest to fault the shadow PTEs back in. We do this even if the address range being notified doesn't correspond to guest memory. This commit adds code to scan the memslot array to find out what range(s) of guest physical addresses corresponds to the host virtual address range being affected. For each such range we flush only the shadow PTEs for the range, on all cpus. Signed-off-by: Paul Mackerras Signed-off-by: Alexander Graf --- arch/powerpc/kvm/book3s_pr.c | 40 ++++++++++++++++++++++++++++++++-------- 1 file changed, 32 insertions(+), 8 deletions(-) diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c index 2f84ed8..6075dbd 100644 --- a/arch/powerpc/kvm/book3s_pr.c +++ b/arch/powerpc/kvm/book3s_pr.c @@ -150,24 +150,48 @@ int kvmppc_core_check_requests(struct kvm_vcpu *vcpu) } /************* MMU Notifiers *************/ +static void do_kvm_unmap_hva(struct kvm *kvm, unsigned long start, + unsigned long end) +{ + long i; + struct kvm_vcpu *vcpu; + struct kvm_memslots *slots; + struct kvm_memory_slot *memslot; + + slots = kvm_memslots(kvm); + kvm_for_each_memslot(memslot, slots) { + unsigned long hva_start, hva_end; + gfn_t gfn, gfn_end; + + hva_start = max(start, memslot->userspace_addr); + hva_end = min(end, memslot->userspace_addr + + (memslot->npages << PAGE_SHIFT)); + if (hva_start >= hva_end) + continue; + /* + * {gfn(page) | page intersects with [hva_start, hva_end)} = + * {gfn, gfn+1, ..., gfn_end-1}. + */ + gfn = hva_to_gfn_memslot(hva_start, memslot); + gfn_end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, memslot); + kvm_for_each_vcpu(i, vcpu, kvm) + kvmppc_mmu_pte_pflush(vcpu, gfn << PAGE_SHIFT, + gfn_end << PAGE_SHIFT); + } +} int kvm_unmap_hva(struct kvm *kvm, unsigned long hva) { trace_kvm_unmap_hva(hva); - /* - * Flush all shadow tlb entries everywhere. This is slow, but - * we are 100% sure that we catch the to be unmapped page - */ - kvm_flush_remote_tlbs(kvm); + do_kvm_unmap_hva(kvm, hva, hva + PAGE_SIZE); return 0; } int kvm_unmap_hva_range(struct kvm *kvm, unsigned long start, unsigned long end) { - /* kvm_unmap_hva flushes everything anyways */ - kvm_unmap_hva(kvm, start); + do_kvm_unmap_hva(kvm, start, end); return 0; } @@ -187,7 +211,7 @@ int kvm_test_age_hva(struct kvm *kvm, unsigned long hva) void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte) { /* The page will get remapped properly on its next fault */ - kvm_unmap_hva(kvm, hva); + do_kvm_unmap_hva(kvm, hva, hva + PAGE_SIZE); } /*****************************************/