From patchwork Wed Apr 8 05:03:07 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ankur Arora X-Patchwork-Id: 11479413 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id F2375912 for ; Wed, 8 Apr 2020 05:07:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D30972083E for ; Wed, 8 Apr 2020 05:07:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="nMq6d/oD" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726523AbgDHFF3 (ORCPT ); Wed, 8 Apr 2020 01:05:29 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:38466 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726345AbgDHFF2 (ORCPT ); Wed, 8 Apr 2020 01:05:28 -0400 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 03853kcS191152; Wed, 8 Apr 2020 05:05:16 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 : mime-version : content-transfer-encoding; s=corp-2020-01-29; bh=f3lI3rU1/Ay+Euh85CO5VhgXpZoiQo2cE1fiMRnLh1w=; b=nMq6d/oDWDkNt2ukCGxAciCrkLF9QtnmmkiNw9DRJnvr/apWes/2eAGiQcGqMSCJVtmo M6AtPpl2ujYjQf5RDs/ynkxYwT9oSpQgxsfAqkfYM3b0ktBcH6b5z2SyZWM2/IcvPU0Q ocfvrZ3Cx8jlOay/V59oyr80m0cPdV01ga90ZR0ZRoz2qZCBTheZFVMeTUWz4GOlnssG SSLKEhsbansJomlmhFH0Bu4iSxQ4+844Zl0p2Ssk3gqZecDCRH8tvncx2cWmCY+MBahS 9fFyUtYO5a4JeZxrmJbEfjc0ZKNjEFNDNmbY4C7ivOd/gfozUSL3n9ED7t1mddqW8YD0 aQ== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by aserp2120.oracle.com with ESMTP id 3091m0s0sj-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 08 Apr 2020 05:05:16 +0000 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 03853LB1158807; Wed, 8 Apr 2020 05:05:15 GMT Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by userp3030.oracle.com with ESMTP id 3091m01fvx-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 08 Apr 2020 05:05:15 +0000 Received: from abhmp0012.oracle.com (abhmp0012.oracle.com [141.146.116.18]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id 03855DaW015230; Wed, 8 Apr 2020 05:05:13 GMT Received: from monad.ca.oracle.com (/10.156.75.81) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 07 Apr 2020 22:05:12 -0700 From: Ankur Arora To: linux-kernel@vger.kernel.org, x86@kernel.org Cc: peterz@infradead.org, hpa@zytor.com, jpoimboe@redhat.com, namit@vmware.com, mhiramat@kernel.org, jgross@suse.com, bp@alien8.de, vkuznets@redhat.com, pbonzini@redhat.com, boris.ostrovsky@oracle.com, mihai.carabas@oracle.com, kvm@vger.kernel.org, xen-devel@lists.xenproject.org, virtualization@lists.linux-foundation.org, Ankur Arora Subject: [RFC PATCH 10/26] x86/paravirt: Add primitives to stage pv-ops Date: Tue, 7 Apr 2020 22:03:07 -0700 Message-Id: <20200408050323.4237-11-ankur.a.arora@oracle.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200408050323.4237-1-ankur.a.arora@oracle.com> References: <20200408050323.4237-1-ankur.a.arora@oracle.com> MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9584 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 bulkscore=0 malwarescore=0 mlxlogscore=999 phishscore=0 spamscore=0 adultscore=0 suspectscore=0 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2004080037 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9584 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 mlxlogscore=999 mlxscore=0 priorityscore=1501 phishscore=0 suspectscore=0 bulkscore=0 lowpriorityscore=0 impostorscore=0 malwarescore=0 clxscore=1015 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2004080037 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Add paravirt_stage_alt() which conditionally selects between a paravirt or native pv-op and then stages it for later patching. Signed-off-by: Ankur Arora --- arch/x86/include/asm/paravirt_types.h | 6 +++ arch/x86/include/asm/text-patching.h | 3 ++ arch/x86/kernel/alternative.c | 58 +++++++++++++++++++++++++++ 3 files changed, 67 insertions(+) diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h index 3b9f6c105397..0c4ca7ad719c 100644 --- a/arch/x86/include/asm/paravirt_types.h +++ b/arch/x86/include/asm/paravirt_types.h @@ -350,6 +350,12 @@ extern struct paravirt_patch_template native_pv_ops; #define PARAVIRT_PATCH(x) \ (offsetof(struct paravirt_patch_template, x) / sizeof(void *)) +#define paravirt_stage_alt(do_stage, op, opfn) \ + (text_poke_pv_stage(PARAVIRT_PATCH(op), \ + (do_stage) ? (opfn) : (native_pv_ops.op))) + +#define paravirt_stage_zero() text_poke_pv_stage_zero() + /* * Neat trick to map patch type back to the call within the * corresponding structure. diff --git a/arch/x86/include/asm/text-patching.h b/arch/x86/include/asm/text-patching.h index e2ef241c261e..706e61e6967d 100644 --- a/arch/x86/include/asm/text-patching.h +++ b/arch/x86/include/asm/text-patching.h @@ -55,6 +55,9 @@ extern void text_poke_bp(void *addr, const void *opcode, size_t len, const void extern void text_poke_queue(void *addr, const void *opcode, size_t len, const void *emulate); extern void text_poke_finish(void); +bool text_poke_pv_stage(u8 type, void *opfn); +void text_poke_pv_stage_zero(void); + #define INT3_INSN_SIZE 1 #define INT3_INSN_OPCODE 0xCC diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index 8189ac21624c..0c335af9ee28 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -1307,3 +1307,61 @@ void __ref text_poke_bp(void *addr, const void *opcode, size_t len, const void * text_poke_loc_init(&tp, addr, opcode, len, emulate); text_poke_bp_batch(&tp, 1); } + +#ifdef CONFIG_PARAVIRT_RUNTIME +struct paravirt_stage_entry { + void *dest; /* pv_op destination */ + u8 type; /* pv_op type */ +}; + +/* + * We don't anticipate many pv-ops being written at runtime. + */ +#define PARAVIRT_STAGE_MAX 8 +struct paravirt_stage { + struct paravirt_stage_entry ops[PARAVIRT_STAGE_MAX]; + u32 count; +}; + +/* Protected by text_mutex */ +static struct paravirt_stage pv_stage; + +/** + * text_poke_pv_stage - Stage paravirt-op for poking. + * @addr: address in struct paravirt_patch_template + * @type: pv-op type + * @opfn: destination of the pv-op + * + * Return: staging status. + */ +bool text_poke_pv_stage(u8 type, void *opfn) +{ + if (system_state == SYSTEM_BOOTING) { /* Passthrough */ + PARAVIRT_PATCH_OP(pv_ops, type) = (long)opfn; + goto out; + } + + lockdep_assert_held(&text_mutex); + + if (PARAVIRT_PATCH_OP(pv_ops, type) == (long)opfn) + goto out; + + if (pv_stage.count >= PARAVIRT_STAGE_MAX) + goto out; + + pv_stage.ops[pv_stage.count].type = type; + pv_stage.ops[pv_stage.count].dest = opfn; + + pv_stage.count++; + + return true; +out: + return false; +} + +void text_poke_pv_stage_zero(void) +{ + lockdep_assert_held(&text_mutex); + pv_stage.count = 0; +} +#endif /* CONFIG_PARAVIRT_RUNTIME */