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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 15F93C433FE for ; Wed, 10 Nov 2021 10:16:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F15F66124B for ; Wed, 10 Nov 2021 10:16:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231390AbhKJKT3 (ORCPT ); Wed, 10 Nov 2021 05:19:29 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40040 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231190AbhKJKTJ (ORCPT ); Wed, 10 Nov 2021 05:19:09 -0500 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 08709C061766 for ; Wed, 10 Nov 2021 02:16:22 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-ID:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To; bh=7EdtArm/rTKJoZlT0o6kCiJxc6A7WaOmxidCofTePr0=; b=Z0neqn2VoHbQwuOMIcmqyvRC8D 2h5mxU/jQEScnJ0ItIYBJTMT6eqZD4cVBMGfd6N6VqKkt399Z2hhqJVmnNMcrccjvuB6fyf7EDVWT 87kMsZjBM+MqJW5kqJWQPNrJiIg7KX3K8u405SduO/77UfprteT39g5/OlLG6vVLP5cNb2y/X30bW +CSCf5I6KzryBhPc2FlTjmY12JCGq6Qzz8L+iTd1RI+Th0D6Her5oGs4zWr3XUFiMLja9Ap2P+fHW QKlKSTXDhq5PtBU8FDWN1Si4AGAq+sbwtZrPBF//4s5Va5l+61+co/OXYEuWbyi31YoPOq+v9YYYE 4ZiA5NKQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1mkkeH-00FFpv-NQ; Wed, 10 Nov 2021 10:16:10 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id BC9A6301BDC; Wed, 10 Nov 2021 11:16:06 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id 97A47203ED507; Wed, 10 Nov 2021 11:16:06 +0100 (CET) Message-ID: <20211110101325.722157053@infradead.org> User-Agent: quilt/0.66 Date: Wed, 10 Nov 2021 11:01:16 +0100 From: Peter Zijlstra To: x86@kernel.org Cc: linux-kernel@vger.kernel.org, peterz@infradead.org, jpoimboe@redhat.com, mark.rutland@arm.com, dvyukov@google.com, seanjc@google.com, pbonzini@redhat.com, mbenes@suse.cz Subject: [PATCH v2 14/23] x86,kvm: Remove .fixup usage References: <20211110100102.250793167@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org KVM instruction emulation has a gnarly hack where the .fixup does a return, however there's already a ret right after the 10b label, so mark that as 11 and have the exception clear %esi to remove the .fixup. Suggested-by: Paolo Bonzini Signed-off-by: Peter Zijlstra (Intel) --- arch/x86/include/asm/extable_fixup_types.h | 1 + arch/x86/kvm/emulate.c | 16 ++++------------ 2 files changed, 5 insertions(+), 12 deletions(-) --- a/arch/x86/include/asm/extable_fixup_types.h +++ b/arch/x86/include/asm/extable_fixup_types.h @@ -46,5 +46,6 @@ #define EX_TYPE_IMM_REG 17 /* reg := (long)imm */ #define EX_TYPE_EFAULT_REG (EX_TYPE_IMM_REG | EX_DATA_IMM(-EFAULT)) #define EX_TYPE_ZERO_REG (EX_TYPE_IMM_REG | EX_DATA_IMM(0)) +#define EX_TYPE_ONE_REG (EX_TYPE_IMM_REG | EX_DATA_IMM(1)) #endif --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -315,7 +315,7 @@ static int fastop(struct x86_emulate_ctx __FOP_FUNC(#name) #define __FOP_RET(name) \ - "ret \n\t" \ + "11: ret \n\t" \ ".size " name ", .-" name "\n\t" #define FOP_RET(name) \ @@ -344,7 +344,7 @@ static int fastop(struct x86_emulate_ctx __FOP_RET(#op "_" #dst) #define FOP1EEX(op, dst) \ - FOP1E(op, dst) _ASM_EXTABLE(10b, kvm_fastop_exception) + FOP1E(op, dst) _ASM_EXTABLE_TYPE_REG(10b, 11b, EX_TYPE_ZERO_REG, %esi) #define FASTOP1(op) \ FOP_START(op) \ @@ -434,10 +434,6 @@ static int fastop(struct x86_emulate_ctx #op " %al \n\t" \ __FOP_RET(#op) -asm(".pushsection .fixup, \"ax\"\n" - "kvm_fastop_exception: xor %esi, %esi; ret\n" - ".popsection"); - FOP_START(setcc) FOP_SETCC(seto) FOP_SETCC(setno) @@ -473,12 +469,8 @@ FOP_END; \ asm volatile("1:" insn "\n" \ "2:\n" \ - ".pushsection .fixup, \"ax\"\n" \ - "3: movl $1, %[_fault]\n" \ - " jmp 2b\n" \ - ".popsection\n" \ - _ASM_EXTABLE(1b, 3b) \ - : [_fault] "+qm"(_fault) inoutclob ); \ + _ASM_EXTABLE_TYPE_REG(1b, 2b, EX_TYPE_ONE_REG, %[_fault]) \ + : [_fault] "+r"(_fault) inoutclob ); \ \ _fault ? X86EMUL_UNHANDLEABLE : X86EMUL_CONTINUE; \ })