From patchwork Mon Dec 18 09:45:13 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Liran Alon X-Patchwork-Id: 10118633 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id AD155603FA for ; Mon, 18 Dec 2017 09:46:06 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A013228D28 for ; Mon, 18 Dec 2017 09:46:06 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 94EBE28DEB; Mon, 18 Dec 2017 09:46:06 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, RCVD_IN_DNSWL_HI, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0DEA028DC5 for ; Mon, 18 Dec 2017 09:46:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758504AbdLRJqE (ORCPT ); Mon, 18 Dec 2017 04:46:04 -0500 Received: from aserp2120.oracle.com ([141.146.126.78]:47802 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758288AbdLRJqC (ORCPT ); Mon, 18 Dec 2017 04:46:02 -0500 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.21/8.16.0.21) with SMTP id vBI9gJT6087969; Mon, 18 Dec 2017 09:45:58 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : in-reply-to : references; s=corp-2017-10-26; bh=SnPmQgiQ/2nmhh8GGtdwXUUUsV0NGlWQbgXz9x6VuvA=; b=kSBoigM+p8dfhjTsoQFHk/8RQOWLoJibG6SL8yQwbdqI1M6T84irhi/FGVHPg6xGjLKQ 8MC9CNxgR/FIHDiBo5atdNZnB5X24/2TEZV5prNXHcXxpTjGhnFYWyZLwvpvOZuubCEL fjdvt+eH/+uKmVBiGJmbptNAcjA+7hSeYv/7sRgZ8lzzlv982Li7pj1T+OIWzDKPc45n G0RhBoBHnznDK7hqy3H9EJAHXGGdRpXD82vTPte/fjLfXD2xUXr7solX8AkdJcCIYtxQ 7LMWpQDir9NEHknhdsctpjsmOJ5Vx6n69Dkv/MsjmBhl2Exk375rQAzKiih9eelzh3hV GA== Received: from userv0021.oracle.com (userv0021.oracle.com [156.151.31.71]) by aserp2120.oracle.com with ESMTP id 2exaxt05xu-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 18 Dec 2017 09:45:58 +0000 Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by userv0021.oracle.com (8.14.4/8.14.4) with ESMTP id vBI9jv1P024848 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 18 Dec 2017 09:45:57 GMT Received: from abhmp0005.oracle.com (abhmp0005.oracle.com [141.146.116.11]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id vBI9jvKI021059; Mon, 18 Dec 2017 09:45:57 GMT Received: from liran-pc.ravello.local (/213.57.127.2) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Mon, 18 Dec 2017 01:45:56 -0800 From: Liran Alon To: pbonzini@redhat.com, rkrcmar@redhat.com, kvm@vger.kernel.org Cc: idan.brown@oracle.com, Liran Alon , Krish Sadhukhan , Konrad Rzeszutek Wilk Subject: [PATCH 4/7] KVM: x86: Emulate only IN/OUT instructions when accessing VMware backdoor Date: Mon, 18 Dec 2017 11:45:13 +0200 Message-Id: <1513590316-4702-5-git-send-email-liran.alon@oracle.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1513590316-4702-1-git-send-email-liran.alon@oracle.com> References: <1513590316-4702-1-git-send-email-liran.alon@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8748 signatures=668649 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=985 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1711220000 definitions=main-1712180128 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Access to VMware backdoor ports is done by one of the IN/OUT/INS/OUTS instructions. These ports must be allowed access even if TSS I/O permission bitmap don't allow it. To handle this, VMX/SVM will be changed in future commits to intercept #GP which was raised by such access and handle it by calling x86 emulator to emulate instruction. If it was one of these instructions, the x86 emulator already handles it correctly (Since commit "KVM: x86: Always allow access to VMware backdoor I/O ports") by not checking these ports against TSS I/O permission bitmap. One may wonder why checking for specific instructions is necessary as we can just forward all #GPs to the x86 emulator. However, it turns out that the x86 emulator is incomplete and therefore certain instructions that can cause #GP cannot be emulated. Such an example is "INT x" (opcode 0xcd) which reach emulate_int() which can only emulate instruction if vCPU is in real-mode. Signed-off-by: Liran Alon Reviewed-by: Nikita Leshenko Reviewed-by: Konrad Rzeszutek Wilk Signed-off-by: Krish Sadhukhan Signed-off-by: Konrad Rzeszutek Wilk --- arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kvm/x86.c | 28 ++++++++++++++++++++++++++++ 2 files changed, 29 insertions(+) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 2b7ea1ac4f86..eff7ecadbc44 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1169,6 +1169,7 @@ enum emulation_result { #define EMULTYPE_RETRY (1 << 3) #define EMULTYPE_NO_REEXECUTE (1 << 4) #define EMULTYPE_NO_UD_ON_FAIL (1 << 5) +#define EMULTYPE_VMWARE (1 << 6) int x86_emulate_instruction(struct kvm_vcpu *vcpu, unsigned long cr2, int emulation_type, void *insn, int insn_len); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 8fd2d3e1bcd4..c52a71c1be0d 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5684,6 +5684,30 @@ static bool kvm_vcpu_check_breakpoint(struct kvm_vcpu *vcpu, int *r) return false; } +static bool is_vmware_backdoor_opcode(struct x86_emulate_ctxt *ctxt) +{ + if (ctxt->opcode_len != 1) + return false; + + switch (ctxt->b) { + case 0xe4: /* IN */ + case 0xe5: + case 0xec: + case 0xed: + case 0xe6: /* OUT */ + case 0xe7: + case 0xee: + case 0xef: + case 0x6c: /* INS */ + case 0x6d: + case 0x6e: /* OUTS */ + case 0x6f: + return true; + } + + return false; +} + int x86_emulate_instruction(struct kvm_vcpu *vcpu, unsigned long cr2, int emulation_type, @@ -5739,6 +5763,10 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, } } + if ((emulation_type & EMULTYPE_VMWARE) && + !is_vmware_backdoor_opcode(ctxt)) + return EMULATE_FAIL; + if (emulation_type & EMULTYPE_SKIP) { kvm_rip_write(vcpu, ctxt->_eip); if (ctxt->eflags & X86_EFLAGS_RF)