From patchwork Wed Jun 22 14:29:13 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xiao Guangrong X-Patchwork-Id: 905162 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter1.kernel.org (8.14.4/8.14.4) with ESMTP id p5MERIMm025294 for ; Wed, 22 Jun 2011 14:27:18 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758082Ab1FVO1Q (ORCPT ); Wed, 22 Jun 2011 10:27:16 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:53248 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1755582Ab1FVO1P (ORCPT ); Wed, 22 Jun 2011 10:27:15 -0400 Received: from tang.cn.fujitsu.com (tang.cn.fujitsu.com [10.167.250.3]) by song.cn.fujitsu.com (Postfix) with ESMTP id 3FCB7170080; Wed, 22 Jun 2011 22:27:13 +0800 (CST) Received: from mailserver.fnst.cn.fujitsu.com (tang.cn.fujitsu.com [127.0.0.1]) by tang.cn.fujitsu.com (8.14.3/8.13.1) with ESMTP id p5MERCoH001741; Wed, 22 Jun 2011 22:27:12 +0800 Received: from localhost.localdomain ([10.167.225.99]) by mailserver.fnst.cn.fujitsu.com (Lotus Domino Release 8.5.1FP4) with ESMTP id 2011062222264924-641949 ; Wed, 22 Jun 2011 22:26:49 +0800 Message-ID: <4E01FC39.2080709@cn.fujitsu.com> Date: Wed, 22 Jun 2011 22:29:13 +0800 From: Xiao Guangrong User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.17) Gecko/20110428 Fedora/3.1.10-1.fc15 Thunderbird/3.1.10 MIME-Version: 1.0 To: Avi Kivity CC: Marcelo Tosatti , LKML , KVM Subject: [PATCH v2 03/22] KVM: x86: fix broken read emulation spans a page boundary References: <4E01FBC9.3020009@cn.fujitsu.com> In-Reply-To: <4E01FBC9.3020009@cn.fujitsu.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2011-06-22 22:26:49, Serialize by Router on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2011-06-22 22:26:49, Serialize complete at 2011-06-22 22:26:49 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 (demeter1.kernel.org [140.211.167.41]); Wed, 22 Jun 2011 14:27:18 +0000 (UTC) If the range spans a boundary, the mmio access can be broke, fix it as write emulation. And we already get the guest physical address, so use it to read guest data directly to avoid walking guest page table again Signed-off-by: Xiao Guangrong --- arch/x86/kvm/x86.c | 41 ++++++++++++++++++++++++++++++++--------- 1 files changed, 32 insertions(+), 9 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 0b803f0..eb27be4 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3944,14 +3944,13 @@ out: } EXPORT_SYMBOL_GPL(kvm_write_guest_virt_system); -static int emulator_read_emulated(struct x86_emulate_ctxt *ctxt, - unsigned long addr, - void *val, - unsigned int bytes, - struct x86_exception *exception) +static int emulator_read_emulated_onepage(unsigned long addr, + void *val, + unsigned int bytes, + struct x86_exception *exception, + struct kvm_vcpu *vcpu) { - struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt); - gpa_t gpa; + gpa_t gpa; int handled; if (vcpu->mmio_read_completed) { @@ -3971,8 +3970,7 @@ static int emulator_read_emulated(struct x86_emulate_ctxt *ctxt, if ((gpa & PAGE_MASK) == APIC_DEFAULT_PHYS_BASE) goto mmio; - if (kvm_read_guest_virt(ctxt, addr, val, bytes, exception) - == X86EMUL_CONTINUE) + if (!kvm_read_guest(vcpu->kvm, gpa, val, bytes)) return X86EMUL_CONTINUE; mmio: @@ -4001,6 +3999,31 @@ mmio: return X86EMUL_IO_NEEDED; } +static int emulator_read_emulated(struct x86_emulate_ctxt *ctxt, + unsigned long addr, + void *val, + unsigned int bytes, + struct x86_exception *exception) +{ + struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt); + + /* Crossing a page boundary? */ + if (((addr + bytes - 1) ^ addr) & PAGE_MASK) { + int rc, now; + + now = -addr & ~PAGE_MASK; + rc = emulator_read_emulated_onepage(addr, val, now, exception, + vcpu); + if (rc != X86EMUL_CONTINUE) + return rc; + addr += now; + val += now; + bytes -= now; + } + return emulator_read_emulated_onepage(addr, val, bytes, exception, + vcpu); +} + int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa, const void *val, int bytes) {