From nobody Sun Apr 12 00:56:44 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=pass; 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; dmarc=pass(p=quarantine dis=none) header.from=redhat.com ARC-Seal: i=1; a=rsa-sha256; t=1772441252; cv=none; d=zohomail.com; s=zohoarc; b=jDcFybm8mHjzG4f0q1SR4QmlNEMaiYKBMKK38OS7LB0DJZfnD1KayvZ3eoEesqbhxDhAqVzEX8AUQ9fajZRT2mM/rYObE5i1ut6Xmr6tf9/OCa3jbaDON2vAuPFKURy5FWeJ6qCBIDYgSRIzhGLqY04flzpJW+PHoDI0ED0AHas= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1772441252; h=Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:Subject:To:To:Message-Id:Reply-To; bh=6jP0wrr/WHTKUeZphGxDZz0G8W/sby2Vn9bBFERnTZc=; b=L2qOH5ZEzxHx0oADbZCPHSKlAS1WhsO0ER0nRCg+Wj+u6+2kYM6Td5ZKZiZK10h0TW3FpUrhII6WOLvPkeT+XfQ9/eiDxGFloLg9j7AcoQ5r391Sai+HdyuOmNb7BNJxCnG+JycPjH/2n8AX0maJj3m5Y7D6OYEJG8+EGkd6Xkw= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; 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; dmarc=pass header.from= (p=quarantine dis=none) Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1772441252972178.30736501129536; Mon, 2 Mar 2026 00:47:32 -0800 (PST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1vwytv-0003aO-E5; Mon, 02 Mar 2026 03:45:15 -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 1vwyta-00026W-2H for qemu-devel@nongnu.org; Mon, 02 Mar 2026 03:44:56 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1vwytX-0001cf-KN for qemu-devel@nongnu.org; Mon, 02 Mar 2026 03:44:53 -0500 Received: from mail-wm1-f70.google.com (mail-wm1-f70.google.com [209.85.128.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-632-CYsQqbAFNCyDQyikXOehqw-1; Mon, 02 Mar 2026 03:44:49 -0500 Received: by mail-wm1-f70.google.com with SMTP id 5b1f17b1804b1-4836cf00787so48172995e9.1 for ; Mon, 02 Mar 2026 00:44:49 -0800 (PST) Received: from [192.168.10.48] ([151.95.144.138]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-483c3b44207sm285275155e9.7.2026.03.02.00.44.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 02 Mar 2026 00:44:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1772441090; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=6jP0wrr/WHTKUeZphGxDZz0G8W/sby2Vn9bBFERnTZc=; b=hU85r5Eff6zKSmxfo4u8dzrPdJNSB5WnCFyYnn3MF/lQw2GqChwh6a/bQCAHhzWp5CST+q /jPy8QAn7ro+mlKgH/itbskEracu1pKirf/2nPRMGG4WKGKVEWkx/VQyFWNHUeruCE4uqD woqqAI7r9fKiV/ekK3Kfxvn4pib0jlc= X-MC-Unique: CYsQqbAFNCyDQyikXOehqw-1 X-Mimecast-MFC-AGG-ID: CYsQqbAFNCyDQyikXOehqw_1772441088 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=google; t=1772441087; x=1773045887; darn=nongnu.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=6jP0wrr/WHTKUeZphGxDZz0G8W/sby2Vn9bBFERnTZc=; b=gfwhVrtn2Z7JBHn+CmDTl2BRHQPfY6beCl4RypusMa09+T8XHAjcp8yHFUJmxyXu0X dbJEaBg931r67HffTAw9Gi14atmoJtZrNH5m12166mo+YV6G2Nzs1mDr7KTP0JvRUbq/ SzVX4W79JtSELFO66L8+JyPaZpx+WjqctHqoQY+joWVfdCONkhtcZWn51P7xrYAlGBj6 k1zWonUGBjkvqIvQpXkrYgsA+Ars0PX3e1lhd5Zty+LsLPlB70N9KFjC6osBuF65Vg1Z GuzsglFchlgaEGl7ekC9cEusRrSWLOsoPr7vFe486/nGE8Y3o0OsRoZlZIXHYdBFjBM7 3eHg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1772441087; x=1773045887; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=6jP0wrr/WHTKUeZphGxDZz0G8W/sby2Vn9bBFERnTZc=; b=axM4XvjIqZctQlhJzkmXvR1mNEVMlx3MslUpYNLfRL3MXNDvSiuKqcbUMA9YqYhX0f dYeWtspoE5H3jRtyJ0uyuF3i0uOFMObF0Yf/2CFxBS2P7W/wwH/VIeRPGsm3lfJskdua mqWh6gan/cT9hKDiWQKGvJfloDL6Q6FWVCJUA0WsoXcGNV3KGUAYdac/utyRS+hNzVYa 7pC/D4GlMe90fZ5og+MGkMZFXuSlDUgaaG27aRvp14YAuc7Xd40BPehVHIuuNQDofROM dCa9ICcxiIrCsBr85gA9YPN+pHKdNqnBvOIgvdy5XmNDH+8sfmBK1Gpt7n1RJ9kcVmyH ASmg== X-Gm-Message-State: AOJu0YwvdrY03dK2V+g/yV7nFL0xFvdKiMGDlzoG6vLWAbjfhR0Ivlsb BwRdlbbJW00z9bTI8qBr9WCgOt8EPQHTrFwcB9MIC1SFT0cMSJYVAsmVkotMZmIMWPsp45+/RRA tJ2gIEEkh5bOEweqtXoQvhSMyAFRuD6/ZAEC3203QZmfiApLF59vzRno7K8/8TcOe9aT8rhYe2d bn4zZxJGAlQQTZ6C0VFojhU3ACtqIMEZ3irU//kF1A X-Gm-Gg: ATEYQzyhBQr1qJFsnRZUL2eLr3cRoSSPjCnv7YlqWmhx01KUNAZlW4lAcEG7CmKpXXQ PiDti5aC+BwQ+2GcVIw08kUl0dEKM9D4vK83Sd3IXq+34DllmBet87SH0Iwnn0h1ua5fPlagZVZ XqvAIVCoxsZfesEBJGKP9vPyXRLL63531uFAfUUUY5acg1Ks9mhybFceTV7t1/VOukwXO+2+4Zh k6Ip7ar2nOdrXF+F+9htsp7yobxyYPuW5ytqmrpFt4nVso1F7T1rzkEUXzrBwMWQxWBv4GPaeyQ 2ZoPbWIemroUynrHntVkPxiqhM71bVWTEsrQhqyC9K/KnqPGth6PcJH3Bb27kvZsHn5XbLzj2r0 fz3nPMiFNHtTqzc7B7ZT95m4O5ceWU6NFFM20mEpfJGvBffeGWcRwa9BXNhFJwuToQmcQ+6ynka TdGCTM5SBTN/m8MdbSCWeM1GStQIk= X-Received: by 2002:a05:600c:608a:b0:47e:e2b8:66e6 with SMTP id 5b1f17b1804b1-483c9934dd3mr205544795e9.14.1772441087216; Mon, 02 Mar 2026 00:44:47 -0800 (PST) X-Received: by 2002:a05:600c:608a:b0:47e:e2b8:66e6 with SMTP id 5b1f17b1804b1-483c9934dd3mr205544395e9.14.1772441086704; Mon, 02 Mar 2026 00:44:46 -0800 (PST) From: Paolo Bonzini To: qemu-devel@nongnu.org Cc: Mohamed Mediouni Subject: [PULL 025/102] target/i386: emulate: propagate memory errors on most reads/writes Date: Mon, 2 Mar 2026 09:42:20 +0100 Message-ID: <20260302084338.473368-26-pbonzini@redhat.com> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260302084338.473368-1-pbonzini@redhat.com> References: <20260302084338.473368-1-pbonzini@redhat.com> 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=170.10.133.124; envelope-from=pbonzini@redhat.com; helo=us-smtp-delivery-124.mimecast.com 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, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=-1, RCVD_IN_MSPIKE_WL=-0.01, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.012, RCVD_IN_VALIDITY_RPBL_BLOCKED=1.188, SPF_HELO_PASS=-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-ZohoMail-DKIM: pass (identity @redhat.com) X-ZM-MESSAGEID: 1772441254138158500 Content-Type: text/plain; charset="utf-8" From: Mohamed Mediouni Use that to not bump RIP for those cases. Warn on read/write from/to unmapped MMIO, but not consider that as an excep= tion. For reads, return 0xFF(s) as the register value in that case. Leaves a coverage gap for read_val_ext(), to be handled in a later commit. Signed-off-by: Mohamed Mediouni Link: https://lore.kernel.org/r/20260223233950.96076-25-mohamed@unpredictab= le.fr Signed-off-by: Paolo Bonzini --- target/i386/emulate/x86_emu.c | 119 +++++++++++++++++++++++++--------- 1 file changed, 88 insertions(+), 31 deletions(-) diff --git a/target/i386/emulate/x86_emu.c b/target/i386/emulate/x86_emu.c index 3aedd638a10..ec6bc798a42 100644 --- a/target/i386/emulate/x86_emu.c +++ b/target/i386/emulate/x86_emu.c @@ -36,11 +36,14 @@ ///////////////////////////////////////////////////////////////////////// =20 #include "qemu/osdep.h" +#include "qemu/error-report.h" #include "panic.h" #include "x86_decode.h" #include "x86.h" #include "x86_emu.h" #include "x86_flags.h" +#include "x86_mmu.h" + =20 #define EXEC_2OP_FLAGS_CMD(env, decode, cmd, FLAGS_FUNC, save_res) \ { \ @@ -175,43 +178,56 @@ void write_val_ext(CPUX86State *env, struct x86_decod= e_op *decode, target_ulong =20 uint8_t *read_mmio(CPUX86State *env, target_ulong ptr, int bytes) { - x86_read_mem(env_cpu(env), env->emu_mmio_buf, ptr, bytes); + MMUTranslateResult res =3D x86_read_mem(env_cpu(env), env->emu_mmio_bu= f, ptr, bytes); + if (res) { + if (res =3D=3D MMU_TRANSLATE_GPA_UNMAPPED) { + memset(env->emu_mmio_buf, 0xFF, bytes); + return env->emu_mmio_buf; + } + return NULL; + } return env->emu_mmio_buf; } =20 =20 -static target_ulong read_val_from_mem(CPUX86State *env, target_long ptr, i= nt size) +static bool read_val_from_mem(CPUX86State *env, target_long ptr, int size,= target_ulong* val) { - target_ulong val; uint8_t *mmio_ptr; =20 mmio_ptr =3D read_mmio(env, ptr, size); + if (mmio_ptr =3D=3D NULL) { + return 1; + } switch (size) { case 1: - val =3D *(uint8_t *)mmio_ptr; + *val =3D *(uint8_t *)mmio_ptr; break; case 2: - val =3D *(uint16_t *)mmio_ptr; + *val =3D *(uint16_t *)mmio_ptr; break; case 4: - val =3D *(uint32_t *)mmio_ptr; + *val =3D *(uint32_t *)mmio_ptr; break; case 8: - val =3D *(uint64_t *)mmio_ptr; + *val =3D *(uint64_t *)mmio_ptr; break; default: VM_PANIC("bad size\n"); break; } - return val; + return 0; } =20 target_ulong read_val_ext(CPUX86State *env, struct x86_decode_op *decode, = int size) { + target_ulong val; if (decode->type =3D=3D X86_VAR_REG) { return read_val_from_reg(decode->regptr, size); } else { - return read_val_from_mem(env, decode->addr, size); + if (read_val_from_mem(env, decode->addr, size, &val)) { + error_report("target/i386/emulate: read_val_ext: reading from = unmapped address."); + } + return val; } } =20 @@ -465,15 +481,17 @@ static inline int get_ZF(CPUX86State *env) { return env->cc_dst ? 0 : CC_Z; } =20 -static inline void string_rep(CPUX86State *env, struct x86_decode *decode, - void (*func)(CPUX86State *env, +static inline bool string_rep(CPUX86State *env, struct x86_decode *decode, + bool (*func)(CPUX86State *env, struct x86_decode *ins), int re= p) { target_ulong rcx =3D read_reg(env, R_ECX, decode->addressing_size); =20 while (rcx !=3D 0) { bool is_cmps_or_scas =3D decode->cmd =3D=3D X86_DECODE_CMD_CMPS ||= decode->cmd =3D=3D X86_DECODE_CMD_SCAS; - func(env, decode); + if (func(env, decode)) { + return 1; + } rcx--; write_reg(env, R_ECX, rcx, decode->addressing_size); if ((PREFIX_REP =3D=3D rep) && !get_ZF(env) && is_cmps_or_scas) { @@ -483,33 +501,44 @@ static inline void string_rep(CPUX86State *env, struc= t x86_decode *decode, break; } } + return 0; } =20 -static void exec_ins_single(CPUX86State *env, struct x86_decode *decode) +static bool exec_ins_single(CPUX86State *env, struct x86_decode *decode) { + MMUTranslateResult res; + target_ulong addr =3D linear_addr_size(env_cpu(env), RDI(env), decode->addressing_size, R_ES); =20 emul_ops->handle_io(env_cpu(env), DX(env), env->emu_mmio_buf, 0, decode->operand_size, 1); - x86_write_mem(env_cpu(env), env->emu_mmio_buf, addr, + res =3D x86_write_mem(env_cpu(env), env->emu_mmio_buf, addr, decode->operand_size); + if (res) { + return 1; + } =20 string_increment_reg(env, R_EDI, decode); + return 0; } =20 static void exec_ins(CPUX86State *env, struct x86_decode *decode) { + bool res; if (decode->rep) { - string_rep(env, decode, exec_ins_single, 0); + res =3D string_rep(env, decode, exec_ins_single, 0); } else { - exec_ins_single(env, decode); + res =3D exec_ins_single(env, decode); } =20 + if (res) { + return; + } env->eip +=3D decode->len; } =20 -static void exec_outs_single(CPUX86State *env, struct x86_decode *decode) +static bool exec_outs_single(CPUX86State *env, struct x86_decode *decode) { target_ulong addr =3D decode_linear_addr(env, decode, RSI(env), R_DS); =20 @@ -519,48 +548,64 @@ static void exec_outs_single(CPUX86State *env, struct= x86_decode *decode) decode->operand_size, 1); =20 string_increment_reg(env, R_ESI, decode); + return 0; } =20 static void exec_outs(CPUX86State *env, struct x86_decode *decode) { + bool res; if (decode->rep) { - string_rep(env, decode, exec_outs_single, 0); + res =3D string_rep(env, decode, exec_outs_single, 0); } else { - exec_outs_single(env, decode); + res =3D exec_outs_single(env, decode); } =20 + if (res) { + return; + } env->eip +=3D decode->len; } =20 -static void exec_movs_single(CPUX86State *env, struct x86_decode *decode) +static bool exec_movs_single(CPUX86State *env, struct x86_decode *decode) { target_ulong src_addr; target_ulong dst_addr; target_ulong val; + MMUTranslateResult res; =20 src_addr =3D decode_linear_addr(env, decode, RSI(env), R_DS); dst_addr =3D linear_addr_size(env_cpu(env), RDI(env), decode->addressing_size, R_ES); =20 - val =3D read_val_from_mem(env, src_addr, decode->operand_size); - x86_write_mem(env_cpu(env), &val, dst_addr, decode->operand_size); + if (read_val_from_mem(env, src_addr, decode->operand_size, &val)) { + return 1; + } + res =3D x86_write_mem(env_cpu(env), &val, dst_addr, decode->operand_si= ze); + if (res) { + return 1; + } =20 string_increment_reg(env, R_ESI, decode); string_increment_reg(env, R_EDI, decode); + return 0; } =20 static void exec_movs(CPUX86State *env, struct x86_decode *decode) { + bool res; if (decode->rep) { - string_rep(env, decode, exec_movs_single, 0); + res =3D string_rep(env, decode, exec_movs_single, 0); } else { - exec_movs_single(env, decode); + res =3D exec_movs_single(env, decode); } =20 + if (res) { + return; + } env->eip +=3D decode->len; } =20 -static void exec_cmps_single(CPUX86State *env, struct x86_decode *decode) +static bool exec_cmps_single(CPUX86State *env, struct x86_decode *decode) { target_ulong src_addr; target_ulong dst_addr; @@ -570,14 +615,19 @@ static void exec_cmps_single(CPUX86State *env, struct= x86_decode *decode) decode->addressing_size, R_ES); =20 decode->op[0].type =3D X86_VAR_IMMEDIATE; - decode->op[0].val =3D read_val_from_mem(env, src_addr, decode->operand= _size); + if (read_val_from_mem(env, src_addr, decode->operand_size, &decode->op= [0].val)) { + return 1; + } decode->op[1].type =3D X86_VAR_IMMEDIATE; - decode->op[1].val =3D read_val_from_mem(env, dst_addr, decode->operand= _size); + if (read_val_from_mem(env, dst_addr, decode->operand_size, &decode->op= [1].val)) { + return 1; + } =20 EXEC_2OP_FLAGS_CMD(env, decode, -, SET_FLAGS_OSZAPC_SUB, false); =20 string_increment_reg(env, R_ESI, decode); string_increment_reg(env, R_EDI, decode); + return 0; } =20 static void exec_cmps(CPUX86State *env, struct x86_decode *decode) @@ -591,17 +641,22 @@ static void exec_cmps(CPUX86State *env, struct x86_de= code *decode) } =20 =20 -static void exec_stos_single(CPUX86State *env, struct x86_decode *decode) +static bool exec_stos_single(CPUX86State *env, struct x86_decode *decode) { target_ulong addr; target_ulong val; + MMUTranslateResult res; =20 addr =3D linear_addr_size(env_cpu(env), RDI(env), decode->addressing_size, R_ES); val =3D read_reg(env, R_EAX, decode->operand_size); - x86_write_mem(env_cpu(env), &val, addr, decode->operand_size); + res =3D x86_write_mem(env_cpu(env), &val, addr, decode->operand_size); + if (res) { + return 1; + } =20 string_increment_reg(env, R_EDI, decode); + return 0; } =20 =20 @@ -616,7 +671,7 @@ static void exec_stos(CPUX86State *env, struct x86_deco= de *decode) env->eip +=3D decode->len; } =20 -static void exec_scas_single(CPUX86State *env, struct x86_decode *decode) +static bool exec_scas_single(CPUX86State *env, struct x86_decode *decode) { target_ulong addr; =20 @@ -627,6 +682,7 @@ static void exec_scas_single(CPUX86State *env, struct x= 86_decode *decode) =20 EXEC_2OP_FLAGS_CMD(env, decode, -, SET_FLAGS_OSZAPC_SUB, false); string_increment_reg(env, R_EDI, decode); + return 0; } =20 static void exec_scas(CPUX86State *env, struct x86_decode *decode) @@ -642,7 +698,7 @@ static void exec_scas(CPUX86State *env, struct x86_deco= de *decode) env->eip +=3D decode->len; } =20 -static void exec_lods_single(CPUX86State *env, struct x86_decode *decode) +static bool exec_lods_single(CPUX86State *env, struct x86_decode *decode) { target_ulong addr; target_ulong val =3D 0; @@ -652,6 +708,7 @@ static void exec_lods_single(CPUX86State *env, struct x= 86_decode *decode) write_reg(env, R_EAX, val, decode->operand_size); =20 string_increment_reg(env, R_ESI, decode); + return 0; } =20 static void exec_lods(CPUX86State *env, struct x86_decode *decode) --=20 2.53.0