From nobody Tue Feb 10 11:15:32 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1770066535798531.1822166517138; Mon, 2 Feb 2026 13:08:55 -0800 (PST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1vn14F-0005Ys-8A; Mon, 02 Feb 2026 16:02:43 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1vn13x-0003EU-Mq; Mon, 02 Feb 2026 16:02:27 -0500 Received: from isrv.corpit.ru ([212.248.84.144]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1vn13v-0004bC-8h; Mon, 02 Feb 2026 16:02:25 -0500 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id 9A6A61851B3; Mon, 02 Feb 2026 23:57:54 +0300 (MSK) Received: from think4mjt.tls.msk.ru (mjtthink.wg.tls.msk.ru [192.168.177.146]) by tsrv.corpit.ru (Postfix) with ESMTP id 6422635B32A; Mon, 02 Feb 2026 23:58:36 +0300 (MSK) From: Michael Tokarev To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Paolo Bonzini , Richard Henderson , Michael Tokarev Subject: [Stable-10.1.4 39/74] target/i386/tcg: allow VEX in 16-bit protected mode Date: Mon, 2 Feb 2026 23:57:50 +0300 Message-ID: <20260202205833.941615-39-mjt@tls.msk.ru> X-Mailer: git-send-email 2.47.3 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=212.248.84.144; envelope-from=mjt@tls.msk.ru; helo=isrv.corpit.ru X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: qemu development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZM-MESSAGEID: 1770066537201158500 Content-Type: text/plain; charset="utf-8" From: Paolo Bonzini VEX is only forbidden in real and vm86 mode; 16-bit protected mode supports it for some unfathomable reason. Cc: qemu-stable@nongnu.org Reviewed-by: Richard Henderson Signed-off-by: Paolo Bonzini (cherry picked from commit ed88bdcfbdcf9d411607cd690f93f915feff6a5b) Signed-off-by: Michael Tokarev diff --git a/target/i386/tcg/decode-new.c.inc b/target/i386/tcg/decode-new.= c.inc index 31aad730fc..24dcf222f3 100644 --- a/target/i386/tcg/decode-new.c.inc +++ b/target/i386/tcg/decode-new.c.inc @@ -2613,20 +2613,16 @@ static void disas_insn(DisasContext *s, CPUState *c= pu) case 0xc5: /* 2-byte VEX */ case 0xc4: /* 3-byte VEX */ /* - * VEX prefixes cannot be used except in 32-bit mode. - * Otherwise the instruction is LES or LDS. + * Bits 6-7 of the first byte must be set except in 64-bit mode. + * Otherwise the instruction is LES or LDS. Not allowed in real m= ode. */ - if (CODE32(s) && !VM86(s)) { + if (PE(s) && !VM86(s)) { static const int pp_prefix[4] =3D { 0, PREFIX_DATA, PREFIX_REPZ, PREFIX_REPNZ }; int vex3, vex2 =3D x86_ldub_code(env, s); =20 if (!CODE64(s) && (vex2 & 0xc0) !=3D 0xc0) { - /* - * 4.1.4.6: In 32-bit mode, bits [7:6] must be 11b, - * otherwise the instruction is LES or LDS. - */ s->pc--; /* rewind the advance_pc() x86_ldub_code() did */ break; } --=20 2.47.3