From patchwork Sat Apr 30 14:50:52 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Takuya Yoshikawa X-Patchwork-Id: 743692 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter2.kernel.org (8.14.4/8.14.3) with ESMTP id p3UEp2XE029619 for ; Sat, 30 Apr 2011 14:51:02 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753363Ab1D3Ou7 (ORCPT ); Sat, 30 Apr 2011 10:50:59 -0400 Received: from mail-pw0-f46.google.com ([209.85.160.46]:33943 "EHLO mail-pw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753121Ab1D3Ou6 (ORCPT ); Sat, 30 Apr 2011 10:50:58 -0400 Received: by pwi15 with SMTP id 15so2150807pwi.19 for ; Sat, 30 Apr 2011 07:50:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:date:from:to:cc:subject:message-id:x-mailer :mime-version:content-type:content-transfer-encoding; bh=0yIa9W77Dx07ZFGUndTySlO8n5iPIPTOixxfZkkR6N8=; b=EDY+l17d8YDw3p7m48nILwwK2B2ceAS3wZNNGrI4NYkUgPeGBngBlkFuTrFs6OB6Qo Ir3WJBal7vfHuyWHWQtZPLHx7nWuwCqQklteqnM2Nx986jKXa64idZFmeqwhtTpy0t+5 kiNL54jRhZYgCMklGRp0sjyAUOqBk90lFjxGo= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:x-mailer:mime-version :content-type:content-transfer-encoding; b=sDZH0hJ28su10qNZlW9WcMPEQMz6Vd8rs8tO4dlBRIfhhljiUN8f9HJNUq+hvII09n uiXeDXxVfgL0yzptr22YFovVdeA9TEFwVgaeg50EJn20OdNhUhekPtaWEoGeUG6nG6Y8 88jWcI/k6Ozfv9gNnmvbF+l4Utm33/aiy0z8E= Received: by 10.68.0.69 with SMTP id 5mr6489050pbc.241.1304175058093; Sat, 30 Apr 2011 07:50:58 -0700 (PDT) Received: from amd (s198099.dynamic.ppp.asahi-net.or.jp [220.157.198.99]) by mx.google.com with ESMTPS id o20sm2609324pbt.50.2011.04.30.07.50.54 (version=SSLv3 cipher=OTHER); Sat, 30 Apr 2011 07:50:55 -0700 (PDT) Date: Sat, 30 Apr 2011 23:50:52 +0900 From: Takuya Yoshikawa To: avi@redhat.com, mtosatti@redhat.com Cc: kvm@vger.kernel.org, yoshikawa.takuya@oss.ntt.co.jp Subject: [PATCH] KVM: MMU: Use ptep_user for cmpxchg_gpte() Message-Id: <20110430235052.b8289513.takuya.yoshikawa@gmail.com> X-Mailer: Sylpheed 3.1.0beta2 (GTK+ 2.22.0; x86_64-pc-linux-gnu) Mime-Version: 1.0 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter2.kernel.org [140.211.167.43]); Sat, 30 Apr 2011 14:51:02 +0000 (UTC) From: Takuya Yoshikawa The address of the gpte was already calculated and stored in ptep_user before entering cmpxchg_gpte(). This patch makes cmpxchg_gpte() to use that to make it clear that we are using the same address during walk_addr_generic(). Signed-off-by: Takuya Yoshikawa --- Note: I tested this but could not see cmpxchg_gpte() being called. Is there any good test case? arch/x86/kvm/paging_tmpl.h | 32 +++++++++++--------------------- 1 files changed, 11 insertions(+), 21 deletions(-) diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index 52450a6..73cdf98 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -79,20 +79,16 @@ static gfn_t gpte_to_gfn_lvl(pt_element_t gpte, int lvl) } static int FNAME(cmpxchg_gpte)(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, - gfn_t table_gfn, unsigned index, - pt_element_t orig_pte, pt_element_t new_pte) + pt_element_t __user *ptep_user, unsigned index, + pt_element_t orig_pte, pt_element_t new_pte) { + int npages; pt_element_t ret; pt_element_t *table; struct page *page; - gpa_t gpa; - gpa = mmu->translate_gpa(vcpu, table_gfn << PAGE_SHIFT, - PFERR_USER_MASK|PFERR_WRITE_MASK); - if (gpa == UNMAPPED_GVA) - return -EFAULT; - - page = gfn_to_page(vcpu->kvm, gpa_to_gfn(gpa)); + npages = get_user_pages_fast((unsigned long)ptep_user, 1, 1, &page); + BUG_ON(npages != 1); table = kmap_atomic(page, KM_USER0); ret = CMPXCHG(&table[index], orig_pte, new_pte); @@ -234,12 +230,9 @@ walk: int ret; trace_kvm_mmu_set_accessed_bit(table_gfn, index, sizeof(pte)); - ret = FNAME(cmpxchg_gpte)(vcpu, mmu, table_gfn, - index, pte, pte|PT_ACCESSED_MASK); - if (ret < 0) { - present = false; - break; - } else if (ret) + ret = FNAME(cmpxchg_gpte)(vcpu, mmu, ptep_user, index, + pte, pte|PT_ACCESSED_MASK); + if (ret) goto walk; mark_page_dirty(vcpu->kvm, table_gfn); @@ -293,12 +286,9 @@ walk: int ret; trace_kvm_mmu_set_dirty_bit(table_gfn, index, sizeof(pte)); - ret = FNAME(cmpxchg_gpte)(vcpu, mmu, table_gfn, index, pte, - pte|PT_DIRTY_MASK); - if (ret < 0) { - present = false; - goto error; - } else if (ret) + ret = FNAME(cmpxchg_gpte)(vcpu, mmu, ptep_user, index, + pte, pte|PT_DIRTY_MASK); + if (ret) goto walk; mark_page_dirty(vcpu->kvm, table_gfn);