From patchwork Mon Sep 11 21:13:16 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= X-Patchwork-Id: 1832489 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=linaro.org header.i=@linaro.org header.a=rsa-sha256 header.s=google header.b=jyM7MOUx; dkim-atps=neutral Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=patchwork.ozlabs.org) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4RkzxY5xkqz1yp5 for ; Tue, 12 Sep 2023 07:14:41 +1000 (AEST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qfoDz-0003dw-Ia; Mon, 11 Sep 2023 17:13:39 -0400 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 1qfoDy-0003dl-Hi for qemu-devel@nongnu.org; Mon, 11 Sep 2023 17:13:38 -0400 Received: from mail-ed1-x531.google.com ([2a00:1450:4864:20::531]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1qfoDv-0005CP-TB for qemu-devel@nongnu.org; Mon, 11 Sep 2023 17:13:38 -0400 Received: by mail-ed1-x531.google.com with SMTP id 4fb4d7f45d1cf-52bcd4db4cbso6191495a12.1 for ; Mon, 11 Sep 2023 14:13:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1694466813; x=1695071613; 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=sHvSEfFrQcxmWmTmnxddV4RlJUGQqaNdgjpuMQl5NIM=; b=jyM7MOUx1+bPlAGDC7O4WSn/9ntVn+1t3/LqNyRZaI+iLdMEJCvwgHDwXVJkVvR8Ee n5BxQxxiO86DGnczOYFVp+gfgD1LKlQN2IFppbyreuMym6NJoH8QuoNVGojzYa9/jh5t a2PZoqbkZFttU88uJrvTxE0GRSdhJHPxzngtpDMkaGsY/zK6gz9BD3MnYGC0hXV0dQIX U8sxuJoHOWTypoS1XwUGISoExBzEyrvIY3eepAFiLHV5yQE8VslS3P4eR8oClZDfZ5FS kFu6ZP/doGXyQAk7hsVoZTocg4xZgRtd99I/zHRYHsRld1RR67ai/HsEYgg6btxKm+Y9 Vk1A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1694466813; x=1695071613; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=sHvSEfFrQcxmWmTmnxddV4RlJUGQqaNdgjpuMQl5NIM=; b=lifOjaAEAsFw3a4ibschAIIcK2j5yOF2fslo+opOliJihDxPffVl5GqWcCaWknd12d KCIbJvnUCSNDaCYEt+rprJHBx6Sbn5C5ZChZmQyGPJAOjqlSTbCawiTNqpqrxugIDMmi HaB9vPU6gw5nJYWjYXawNT3iBNkRoi9ycGSC66X2euWR1vDPHNXaQcuWFJb8Mq50ffsJ ZQCA0rOjTDSLKjAdKOPQwX9K8jxdx8WPx3pZ442eqvTfAHe8tosmi1oEjczvLcjREpjh FyoTS+Q8gTkNjKyXTEzaGLkOhmX8RCMDza9CHsiIB8eNG0XeLpuB1+E3ilu9WuRo03nw PoSQ== X-Gm-Message-State: AOJu0YyN9o0YtKYK5PiUiPmwS0QAhy5bP025DjvD3YF7ims1eL78I5Xx bxLdQ2qkmx+oaHiLTFjJB3GCHDStO2SdedDK4fc= X-Google-Smtp-Source: AGHT+IHlbEUdBzYSoedkHroPwt4AlkXyt7WAKtmPFviYLtFN5z7i4ltmDFHgoedOXFLkMQBoGsRLxA== X-Received: by 2002:a17:906:74c7:b0:9a1:e758:fc6e with SMTP id z7-20020a17090674c700b009a1e758fc6emr9487589ejl.10.1694466813214; Mon, 11 Sep 2023 14:13:33 -0700 (PDT) Received: from m1x-phil.lan (tfy62-h01-176-171-221-76.dsl.sta.abo.bbox.fr. [176.171.221.76]) by smtp.gmail.com with ESMTPSA id hb19-20020a170906b89300b009a1fd22257fsm5820515ejb.207.2023.09.11.14.13.31 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Mon, 11 Sep 2023 14:13:32 -0700 (PDT) From: =?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= To: qemu-devel@nongnu.org Cc: kvm@vger.kernel.org, Daniel Henrique Barboza , Paolo Bonzini , Stefan Hajnoczi , Michael Tokarev , Richard Henderson , Marcelo Tosatti , =?utf-8?q?Daniel_P_=2E_Berrang=C3=A9?= , =?utf-8?q?Phi?= =?utf-8?q?lippe_Mathieu-Daud=C3=A9?= , Kevin Wolf Subject: [RFC PATCH v4 2/3] target/i386: Restrict system-specific features from user emulation Date: Mon, 11 Sep 2023 23:13:16 +0200 Message-ID: <20230911211317.28773-3-philmd@linaro.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230911211317.28773-1-philmd@linaro.org> References: <20230911211317.28773-1-philmd@linaro.org> MIME-Version: 1.0 Received-SPF: pass client-ip=2a00:1450:4864:20::531; envelope-from=philmd@linaro.org; helo=mail-ed1-x531.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, 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: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Since commits 3adce820cf ("target/i386: Remove unused KVM stubs") and ef1cf6890f ("target/i386: Allow elision of kvm_hv_vpindex_settable()"), when building on a x86 host configured as: $ ./configure --cc=clang \ --target-list=x86_64-linux-user,x86_64-softmmu \ --enable-debug we get: [71/71] Linking target qemu-x86_64 FAILED: qemu-x86_64 /usr/bin/ld: libqemu-x86_64-linux-user.fa.p/target_i386_cpu.c.o: in function `cpu_x86_cpuid': cpu.c:(.text+0x1374): undefined reference to `kvm_arch_get_supported_cpuid' /usr/bin/ld: libqemu-x86_64-linux-user.fa.p/target_i386_cpu.c.o: in function `x86_cpu_filter_features': cpu.c:(.text+0x81c2): undefined reference to `kvm_arch_get_supported_cpuid' /usr/bin/ld: cpu.c:(.text+0x81da): undefined reference to `kvm_arch_get_supported_cpuid' /usr/bin/ld: cpu.c:(.text+0x81f2): undefined reference to `kvm_arch_get_supported_cpuid' /usr/bin/ld: cpu.c:(.text+0x820a): undefined reference to `kvm_arch_get_supported_cpuid' /usr/bin/ld: libqemu-x86_64-linux-user.fa.p/target_i386_cpu.c.o:cpu.c:(.text+0x8225): more undefined references to `kvm_arch_get_supported_cpuid' follow clang: error: linker command failed with exit code 1 (use -v to see invocation) ninja: build stopped: subcommand failed. libqemu-x86_64-linux-user.fa is user emulation specific, so having system emulation code called there is dubious. '--enable-debug' disables optimizations (CFLAGS=-O0). While at this (un)optimization level GCC eliminate the following dead code (CPP output of mentioned build): static void x86_cpu_get_supported_cpuid(uint32_t func, uint32_t index, uint32_t *eax, uint32_t *ebx, uint32_t *ecx, uint32_t *edx) { if ((0)) { *eax = kvm_arch_get_supported_cpuid(kvm_state, func, index, R_EAX); *ebx = kvm_arch_get_supported_cpuid(kvm_state, func, index, R_EBX); *ecx = kvm_arch_get_supported_cpuid(kvm_state, func, index, R_ECX); *edx = kvm_arch_get_supported_cpuid(kvm_state, func, index, R_EDX); } else if (0) { *eax = 0; *ebx = 0; *ecx = 0; *edx = 0; } else { *eax = 0; *ebx = 0; *ecx = 0; *edx = 0; } } Clang does not. Instead of trying to deal with compiler specific checks around __OPTIMIZE__ (see commit 2140cfa51d "i386: Fix build by providing stub kvm_arch_get_supported_cpuid()"), simply restrict code belonging to system emulation, easing user emulation linking. Reported-by: Kevin Wolf Signed-off-by: Philippe Mathieu-Daudé --- RFC: I might have been overzealous in x86_cpu_expand_features(), please double check. --- target/i386/cpu.c | 47 +++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 45 insertions(+), 2 deletions(-) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 760428d4dc..8b57708604 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -1664,6 +1664,7 @@ static inline uint64_t x86_cpu_xsave_xss_components(X86CPU *cpu) cpu->env.features[FEAT_XSAVE_XSS_LO]; } +#ifndef CONFIG_USER_ONLY /* * Returns the set of feature flags that are supported and migratable by * QEMU, for a given FeatureWord. @@ -1686,6 +1687,7 @@ static uint64_t x86_cpu_get_migratable_flags(FeatureWord w) } return r; } +#endif /* !CONFIG_USER_ONLY */ void host_cpuid(uint32_t function, uint32_t count, uint32_t *eax, uint32_t *ebx, uint32_t *ecx, uint32_t *edx) @@ -5677,8 +5679,6 @@ CpuDefinitionInfoList *qmp_query_cpu_definitions(Error **errp) return cpu_list; } -#endif /* !CONFIG_USER_ONLY */ - uint64_t x86_cpu_get_supported_feature_word(FeatureWord w, bool migratable_only) { @@ -5781,6 +5781,38 @@ static void x86_cpu_get_cache_cpuid(uint32_t func, uint32_t index, } } +#else /* CONFIG_USER_ONLY */ + +uint64_t x86_cpu_get_supported_feature_word(FeatureWord w, + bool migratable_only) +{ + FeatureWordInfo *wi = &feature_word_info[w]; + + return wi->tcg_features; +} + +static void x86_cpu_get_supported_cpuid(uint32_t func, uint32_t index, + uint32_t *eax, uint32_t *ebx, + uint32_t *ecx, uint32_t *edx) +{ + *eax = 0; + *ebx = 0; + *ecx = 0; + *edx = 0; +} + +static void x86_cpu_get_cache_cpuid(uint32_t func, uint32_t index, + uint32_t *eax, uint32_t *ebx, + uint32_t *ecx, uint32_t *edx) +{ + *eax = 0; + *ebx = 0; + *ecx = 0; + *edx = 0; +} + +#endif /* !CONFIG_USER_ONLY */ + /* * Only for builtin_x86_defs models initialized with x86_register_cpudef_types. */ @@ -6163,6 +6195,7 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count, } *edx = env->features[FEAT_7_0_EDX]; /* Feature flags */ +#ifndef CONFIG_USER_ONLY /* * SGX cannot be emulated in software. If hardware does not * support enabling SGX and/or SGX flexible launch control, @@ -6181,6 +6214,7 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count, CPUID_7_0_ECX_SGX_LC))) { *ecx &= ~CPUID_7_0_ECX_SGX_LC; } +#endif } else if (count == 1) { *eax = env->features[FEAT_7_1_EAX]; *edx = env->features[FEAT_7_1_EDX]; @@ -6876,6 +6910,8 @@ static void mce_init(X86CPU *cpu) } } +#ifndef CONFIG_USER_ONLY + static void x86_cpu_adjust_level(X86CPU *cpu, uint32_t *min, uint32_t value) { if (*min < value) { @@ -6948,6 +6984,8 @@ static void x86_cpu_enable_xsave_components(X86CPU *cpu) env->features[FEAT_XSAVE_XSS_HI] = mask >> 32; } +#endif /* !CONFIG_USER_ONLY */ + /***** Steps involved on loading and filtering CPUID data * * When initializing and realizing a CPU object, the steps @@ -7040,6 +7078,7 @@ void x86_cpu_expand_features(X86CPU *cpu, Error **errp) } } +#ifndef CONFIG_USER_ONLY if (!kvm_enabled() || !cpu->expose_kvm) { env->features[FEAT_KVM] = 0; } @@ -7111,6 +7150,8 @@ void x86_cpu_expand_features(X86CPU *cpu, Error **errp) return; } +#endif /* !CONFIG_USER_ONLY */ + /* Set cpuid_*level* based on cpuid_min_*level, if not explicitly set */ if (env->cpuid_level_func7 == UINT32_MAX) { env->cpuid_level_func7 = env->cpuid_min_level_func7; @@ -7152,6 +7193,7 @@ static void x86_cpu_filter_features(X86CPU *cpu, bool verbose) mark_unavailable_features(cpu, w, unavailable_features, prefix); } +#ifndef CONFIG_USER_ONLY if ((env->features[FEAT_7_0_EBX] & CPUID_7_0_EBX_INTEL_PT) && kvm_enabled()) { KVMState *s = CPU(cpu)->kvm_state; @@ -7179,6 +7221,7 @@ static void x86_cpu_filter_features(X86CPU *cpu, bool verbose) mark_unavailable_features(cpu, FEAT_7_0_EBX, CPUID_7_0_EBX_INTEL_PT, prefix); } } +#endif } static void x86_cpu_hyperv_realize(X86CPU *cpu)