From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=3.0 tests=FROM_EXCESS_BASE64, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D3DF9C43387 for ; Fri, 11 Jan 2019 13:30:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B04B02133F for ; Fri, 11 Jan 2019 13:30:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732648AbfAKNaL (ORCPT ); Fri, 11 Jan 2019 08:30:11 -0500 Received: from mx1.redhat.com ([209.132.183.28]:59846 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728853AbfAKNaL (ORCPT ); Fri, 11 Jan 2019 08:30:11 -0500 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 0C98EC04F4DD; Fri, 11 Jan 2019 13:30:11 +0000 (UTC) Received: from flask (unknown [10.40.205.161]) by smtp.corp.redhat.com (Postfix) with SMTP id 287F05D75D; Fri, 11 Jan 2019 13:30:03 +0000 (UTC) Received: by flask (sSMTP sendmail emulation); Fri, 11 Jan 2019 14:30:03 +0100 Date: Fri, 11 Jan 2019 14:30:03 +0100 From: Radim =?utf-8?B?S3LEjW3DocWZ?= To: Peng Hao Cc: pbonzini@redhat.com, tglx@linutronix.de, x86@kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RESEND PATCH] kvm/x86: propagate fetch fault into guest Message-ID: <20190111133002.GA14852@flask> References: <1545652830-65253-1-git-send-email-peng.hao2@zte.com.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1545652830-65253-1-git-send-email-peng.hao2@zte.com.cn> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Fri, 11 Jan 2019 13:30:11 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2018-12-24 20:00+0800, Peng Hao: > When handling ept misconfig exit, it will call emulate instruction > with insn_len = 0. The decode instruction function may return a fetch > fault and should propagate to guest. > > The problem will result to emulation fail. > KVM internal error. Suberror: 1 > emulation failure > EAX=f81a0024 EBX=f6a07000 ECX=f6a0737c EDX=f8be0118 > ESI=f6a0737c EDI=00000021 EBP=f6929f98 ESP=f6929f98 > EIP=f8bdd141 EFL=00010086 [--S--P-] CPL=0 II=0 A20=1 SMM=0 HLT=0 > ES =007b 00000000 ffffffff 00c0f300 DPL=3 DS [-WA] > CS =0060 00000000 ffffffff 00c09b00 DPL=0 CS32 [-RA] > SS =0068 00000000 ffffffff 00c09300 DPL=0 DS [-WA] > DS =007b 00000000 ffffffff 00c0f300 DPL=3 DS [-WA] > FS =00d8 2c044000 ffffffff 00809300 DPL=0 DS16 [-WA] > GS =0033 081a44c8 01000fff 00d0f300 DPL=3 DS [-WA] > LDT=0000 00000000 ffffffff 00000000 > TR =0080 f6ea0c80 0000206b 00008b00 DPL=0 TSS32-busy > GDT= f6e99000 000000ff > IDT= fffbb000 000007ff > CR0=80050033 CR2=b757d000 CR3=35d31000 CR4=001406d0 Do you have a test case for this? > Signed-off-by: Peng Hao > --- > diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c > @@ -5114,8 +5114,11 @@ int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len) > memcpy(ctxt->fetch.data, insn, insn_len); > else { > rc = __do_insn_fetch_bytes(ctxt, 1); > - if (rc != X86EMUL_CONTINUE) > + if (rc != X86EMUL_CONTINUE) { > + if (rc == X86EMUL_PROPAGATE_FAULT) > + ctxt->have_exception = true; > return rc; (Ugh, the caller expects EMULATION_FAILED instead of rc.) > + } > } > > switch (mode) { > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > @@ -6333,8 +6333,10 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, > if (reexecute_instruction(vcpu, cr2, write_fault_to_spt, > emulation_type)) > return EMULATE_DONE; > - if (ctxt->have_exception && inject_emulated_exception(vcpu)) I don't understand what that return value check was supposed to do, but yours version seems good. I have queued it for rc3 to get some extra testing, thanks.