From nobody Mon Feb 9 21:03:25 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass(p=quarantine dis=none) header.from=suse.com ARC-Seal: i=1; a=rsa-sha256; t=1731423634; cv=none; d=zohomail.com; s=zohoarc; b=a+QSPDfObRObKF+H1VuC0ytoP2qSuRCL5h+SMS1IxCK5xfSFWBk7z7LbcUS/DX2z2RfktWBvo7SkOCxNhhVyMJEa0mxhwFpHiTNIvh61oElzLj92R/igP+mBJyVOlvPxCO0AN1sccY2H+SVXwLZD7dtU6GrGEojoox+TJiUonCE= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1731423634; h=Content-Type:Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:Subject:To:To:Message-Id:Reply-To; bh=2e73lNpqWAQaerd/QqjxQ4QTEF6fQc4PS73hY19V+HU=; b=KCigHaOZ69Z/O160kcrHksC/boGNG8+Q3b62Jy7E9jzTGYDMqHoG/ccjZ8McWgPB3RRPPZEAnTbL90U+7+nxqr88ebmSeoI4mTINotPmW0WkyPk2ywwXTGCLvfq3Hj0pcIRTQdyaHZeSq47jgWIA4W8wM2XSM5vuqAhSCuiRYho= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass header.from= (p=quarantine dis=none) Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 173142363417932.268184760294275; Tue, 12 Nov 2024 07:00:34 -0800 (PST) Received: from list by lists.xenproject.org with outflank-mailman.834706.1250484 (Exim 4.92) (envelope-from ) id 1tAsNP-0006pb-Ql; Tue, 12 Nov 2024 15:00:19 +0000 Received: by outflank-mailman (output) from mailman id 834706.1250484; Tue, 12 Nov 2024 15:00:19 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1tAsNP-0006pU-O2; Tue, 12 Nov 2024 15:00:19 +0000 Received: by outflank-mailman (input) for mailman id 834706; Tue, 12 Nov 2024 15:00:18 +0000 Received: from se1-gles-sth1-in.inumbo.com ([159.253.27.254] helo=se1-gles-sth1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1tAsNO-0005Nh-Fm for xen-devel@lists.xenproject.org; Tue, 12 Nov 2024 15:00:18 +0000 Received: from mail-wm1-x332.google.com (mail-wm1-x332.google.com [2a00:1450:4864:20::332]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id d2bd0d6c-a106-11ef-a0c6-8be0dac302b0; Tue, 12 Nov 2024 16:00:15 +0100 (CET) Received: by mail-wm1-x332.google.com with SMTP id 5b1f17b1804b1-4315839a7c9so54933045e9.3 for ; Tue, 12 Nov 2024 07:00:15 -0800 (PST) Received: from [10.156.60.236] (ip-037-024-206-209.um08.pools.vodafone-ip.de. [37.24.206.209]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-381ed970d4fsm15943613f8f.5.2024.11.12.07.00.13 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 12 Nov 2024 07:00:14 -0800 (PST) X-Outflank-Mailman: Message body and most headers restored to incoming version X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: d2bd0d6c-a106-11ef-a0c6-8be0dac302b0 X-Custom-Connection: eyJyZW1vdGVpcCI6IjJhMDA6MTQ1MDo0ODY0OjIwOjozMzIiLCJoZWxvIjoibWFpbC13bTEteDMzMi5nb29nbGUuY29tIn0= X-Custom-Transaction: eyJpZCI6ImQyYmQwZDZjLWExMDYtMTFlZi1hMGM2LThiZTBkYWMzMDJiMCIsInRzIjoxNzMxNDIzNjE1LjExNTIzMywic2VuZGVyIjoiamJldWxpY2hAc3VzZS5jb20iLCJyZWNpcGllbnQiOiJ4ZW4tZGV2ZWxAbGlzdHMueGVucHJvamVjdC5vcmcifQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=google; t=1731423614; x=1732028414; darn=lists.xenproject.org; h=content-transfer-encoding:in-reply-to:autocrypt:content-language :references:cc:to:from:subject:user-agent:mime-version:date :message-id:from:to:cc:subject:date:message-id:reply-to; bh=2e73lNpqWAQaerd/QqjxQ4QTEF6fQc4PS73hY19V+HU=; b=O3et9FqtEJNDsiAPMa8csFZDpmlfRSWNngaH9fMs65bUTcZtAWUJPpNyKmTVnQCRrr ub78j4f4M4ddkKLJTebqQBXPwoSaL8XrAkPr7NjtBOBnZCEaScgV2lLUeKcuCfbBg+mf gxd/puXol131YaVaAigCcBpRt2CpVpjMn0PpYDqB4SCQKjX0jr5otSVUqctS7Po5d1nM xDBoDXMPQlrEei3ayvqK44hOMuRBdH0eDTqUDFoe23WcIW1cNnZ9pzppX93scid0Mmkz b4r3vEY+YD6Qzw0nNvDaTd7pKqmctaiPG4ZdpZVWRWMngs/SFSMYsqdW9d/Gu3h9iudO nVpA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1731423614; x=1732028414; h=content-transfer-encoding:in-reply-to:autocrypt:content-language :references:cc:to:from:subject:user-agent:mime-version:date :message-id:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=2e73lNpqWAQaerd/QqjxQ4QTEF6fQc4PS73hY19V+HU=; b=XmCutP59hqrUAJbYMv2PST3W5u/mpiqF8Xq9CE2g4Vy101I5lI3di5Z8EsqzMAkqQj dX8oDUr+zvABqK1oFSe7kTtJ52dJQ53P+AcmmJwslqXfsA5Z0i1BCn1bzn0g8a8G5h+Q zJnSiVSKhGRu7WYMxl0ylf2CtvsMlY4KT+gB+mSxs7I4ZsjeYKLRVW2KDRm4nYRRjA13 cimODBpAcE833qQjJg7WcPrfMwva4FdLZvCAtSlx+uNUEbX4L0qQc/gNOuSOaFUshi8e GItG0JfaNQvyya3pjyRGeJYNXFyRCYgp5pqMDByralof5/LmZJKsXOdjxSSpv3nL5wdh b8gg== X-Gm-Message-State: AOJu0Yx0/HbW/AAOHZhSP/WGUGSMlnDheojOOOrIHM9Wn8icDUks9G1t YOwZ/5rTcyCjc2RoIwL0G5m06sE+8Z3PIhZkaHnAvCXotbUCR9ssAEOVHN9HU6yUywpz5N17MSk = X-Google-Smtp-Source: AGHT+IF67DGfviVwmtxPkZ3i+sojSiv+/cZPnownk4sLN26pXgCUrSd3iPqqJI6f11YwAxrBj2WyfQ== X-Received: by 2002:a05:6000:480b:b0:37d:45f0:dd08 with SMTP id ffacd0b85a97d-381f186731amr14552355f8f.11.1731423614413; Tue, 12 Nov 2024 07:00:14 -0800 (PST) Message-ID: <39de64e1-c615-4ec3-ad05-ff99f27a8e30@suse.com> Date: Tue, 12 Nov 2024 16:00:13 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: [PATCH 2/2] x86emul: ignore VEX.W for BMI{1,2} insns in 32-bit mode From: Jan Beulich To: "xen-devel@lists.xenproject.org" Cc: Andrew Cooper , =?UTF-8?Q?Roger_Pau_Monn=C3=A9?= References: <367ba117-f376-433b-bd70-586d7519d94c@suse.com> Content-Language: en-US Autocrypt: addr=jbeulich@suse.com; keydata= xsDiBFk3nEQRBADAEaSw6zC/EJkiwGPXbWtPxl2xCdSoeepS07jW8UgcHNurfHvUzogEq5xk hu507c3BarVjyWCJOylMNR98Yd8VqD9UfmX0Hb8/BrA+Hl6/DB/eqGptrf4BSRwcZQM32aZK 7Pj2XbGWIUrZrd70x1eAP9QE3P79Y2oLrsCgbZJfEwCgvz9JjGmQqQkRiTVzlZVCJYcyGGsD /0tbFCzD2h20ahe8rC1gbb3K3qk+LpBtvjBu1RY9drYk0NymiGbJWZgab6t1jM7sk2vuf0Py O9Hf9XBmK0uE9IgMaiCpc32XV9oASz6UJebwkX+zF2jG5I1BfnO9g7KlotcA/v5ClMjgo6Gl MDY4HxoSRu3i1cqqSDtVlt+AOVBJBACrZcnHAUSuCXBPy0jOlBhxPqRWv6ND4c9PH1xjQ3NP nxJuMBS8rnNg22uyfAgmBKNLpLgAGVRMZGaGoJObGf72s6TeIqKJo/LtggAS9qAUiuKVnygo 3wjfkS9A3DRO+SpU7JqWdsveeIQyeyEJ/8PTowmSQLakF+3fote9ybzd880fSmFuIEJldWxp Y2ggPGpiZXVsaWNoQHN1c2UuY29tPsJgBBMRAgAgBQJZN5xEAhsDBgsJCAcDAgQVAggDBBYC AwECHgECF4AACgkQoDSui/t3IH4J+wCfQ5jHdEjCRHj23O/5ttg9r9OIruwAn3103WUITZee e7Sbg12UgcQ5lv7SzsFNBFk3nEQQCACCuTjCjFOUdi5Nm244F+78kLghRcin/awv+IrTcIWF hUpSs1Y91iQQ7KItirz5uwCPlwejSJDQJLIS+QtJHaXDXeV6NI0Uef1hP20+y8qydDiVkv6l IreXjTb7DvksRgJNvCkWtYnlS3mYvQ9NzS9PhyALWbXnH6sIJd2O9lKS1Mrfq+y0IXCP10eS FFGg+Av3IQeFatkJAyju0PPthyTqxSI4lZYuJVPknzgaeuJv/2NccrPvmeDg6Coe7ZIeQ8Yj t0ARxu2xytAkkLCel1Lz1WLmwLstV30g80nkgZf/wr+/BXJW/oIvRlonUkxv+IbBM3dX2OV8 AmRv1ySWPTP7AAMFB/9PQK/VtlNUJvg8GXj9ootzrteGfVZVVT4XBJkfwBcpC/XcPzldjv+3 HYudvpdNK3lLujXeA5fLOH+Z/G9WBc5pFVSMocI71I8bT8lIAzreg0WvkWg5V2WZsUMlnDL9 mpwIGFhlbM3gfDMs7MPMu8YQRFVdUvtSpaAs8OFfGQ0ia3LGZcjA6Ik2+xcqscEJzNH+qh8V m5jjp28yZgaqTaRbg3M/+MTbMpicpZuqF4rnB0AQD12/3BNWDR6bmh+EkYSMcEIpQmBM51qM EKYTQGybRCjpnKHGOxG0rfFY1085mBDZCH5Kx0cl0HVJuQKC+dV2ZY5AqjcKwAxpE75MLFkr wkkEGBECAAkFAlk3nEQCGwwACgkQoDSui/t3IH7nnwCfcJWUDUFKdCsBH/E5d+0ZnMQi+G0A nAuWpQkjM1ASeQwSHEeAWPgskBQL In-Reply-To: <367ba117-f376-433b-bd70-586d7519d94c@suse.com> Content-Transfer-Encoding: quoted-printable X-ZohoMail-DKIM: pass (identity @suse.com) X-ZM-MESSAGEID: 1731423634643116600 Content-Type: text/plain; charset="utf-8" While result values and other status flags are unaffected as long as we can ignore the case of registers having their upper 32 bits non-zero outside of 64-bit mode, EFLAGS.SF may obtain a wrong value when we mistakenly re-execute the original insn with VEX.W set. Note that the memory access, if any, is correctly carried out as 32-bit regardless of VEX.W. Internal state also isn't leaked, as the field the memory value is read into (which is then wrongly accessed as a 64-bit quantity when executing the stub) is pre-initialized to zero. Fixes: 771daacd197a ("x86emul: support BMI1 insns") Signed-off-by: Jan Beulich --- a/tools/tests/x86_emulator/test_x86_emulator.c +++ b/tools/tests/x86_emulator/test_x86_emulator.c @@ -2021,6 +2021,30 @@ int main(int argc, char **argv) (EFLAGS_ALWAYS_SET | X86_EFLAGS_SF) || !check_eip(blsr) ) goto fail; + +#ifdef __x86_64__ + /* Re-test with VEX.W set while emulating 32-bit mode. */ + ctxt.lma =3D 0; + ctxt.addr_size =3D 32; + ctxt.sp_size =3D 32; + + memcpy(instr, blsr, blsr_end - blsr); + instr[2] |=3D 0x80; + regs.rip =3D (unsigned long)&instr[0]; + regs.eflags =3D EFLAGS_ALWAYS_SET | X86_EFLAGS_OF | X86_EFLAGS_ZF = | \ + X86_EFLAGS_CF; + rc =3D x86_emulate(&ctxt, &emulops); + if ( (rc !=3D X86EMUL_OKAY) || regs.ecx !=3D 0xfedcba90 || + (regs.eflags & (EFLAGS_MASK & ~(X86_EFLAGS_AF | X86_EFLAGS_PF= ))) !=3D + (EFLAGS_ALWAYS_SET | X86_EFLAGS_SF) || + (regs.rip !=3D (unsigned long)&instr[blsr_end - blsr]) ) + goto fail; + + ctxt.lma =3D 1; + ctxt.addr_size =3D 64; + ctxt.sp_size =3D 64; +#endif + printf("okay\n"); } else --- a/xen/arch/x86/x86_emulate/x86_emulate.c +++ b/xen/arch/x86/x86_emulate/x86_emulate.c @@ -6896,6 +6896,8 @@ x86_emulate( *pvex =3D vex; pvex->b =3D 1; pvex->r =3D 1; + if ( !mode_64bit() ) + pvex->w =3D 0; pvex->reg =3D 0xf; /* rAX */ buf[3] =3D b; buf[4] =3D 0x09; /* reg=3DrCX r/m=3D(%rCX) */ @@ -6930,6 +6932,8 @@ x86_emulate( *pvex =3D vex; pvex->b =3D 1; pvex->r =3D 1; + if ( !mode_64bit() ) + pvex->w =3D 0; pvex->reg =3D 0xf; /* rAX */ buf[3] =3D b; buf[4] =3D (modrm & 0x38) | 0x01; /* r/m=3D(%rCX) */