From patchwork Sat Sep 14 11:01:27 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chuang Xu X-Patchwork-Id: 13804363 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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 05B8BC02190 for ; Sat, 14 Sep 2024 11:03:01 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1spQXg-0003K0-J2; Sat, 14 Sep 2024 07:02:16 -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 1spQXf-0003Ib-1s for qemu-devel@nongnu.org; Sat, 14 Sep 2024 07:02:15 -0400 Received: from mail-pg1-x52a.google.com ([2607:f8b0:4864:20::52a]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1spQXY-0001R1-Kt for qemu-devel@nongnu.org; Sat, 14 Sep 2024 07:02:14 -0400 Received: by mail-pg1-x52a.google.com with SMTP id 41be03b00d2f7-7d50e865b7aso2686160a12.0 for ; Sat, 14 Sep 2024 04:02:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance.com; s=google; t=1726311722; x=1726916522; darn=nongnu.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=GR/HGyAr9qr2GTW6o3wD5zxUc45IeTLnMegr1ek0CeM=; b=P3YSUlFYP8r3/D6n6+ujaxXxMmch+gerIflGaoGfUeNms+EML7fNP0SbDV61qCZEMj X+sduAtKWl/mmgTpto1l5Hs3GPR6oPa9nDpJx/lx51+BmI6lC7MPgFx8aRmqfi7vlFSq 3JzOB5HfqcGEhrlpVPBNHz8rsTEKT9ifoP1KZFHYWV1xsj7o2+VIzPMSOJ+pXdsCV134 s8cu5l7CyQKsKmqFC4KSnPtixJxUqr3jOkrup9ldH9Uv5fheYyrtM+R+c7tDMoROFJCm 2+hTPS5T8x5IYyppoLcgTh4QVTaD0xj7W17JItEyRj2ItybYjJpY4XS8fUM9JitQNAfY pCFQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1726311722; x=1726916522; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=GR/HGyAr9qr2GTW6o3wD5zxUc45IeTLnMegr1ek0CeM=; b=TqXRdJYK4RkHIvN585IGDsgKp59JxklLQvoMwo3nXwQoc/ax3MpZ9ULsxvUMRzPTa8 1PfOk0673uieE/EcozUhSpoVxesq3Qs6AbLfVMOg6iJZX7Fq19oTdBBQQB967G/gheEG s8nulM7sIh6PAa6E+7TJQhopAg7QfjDCYWt6l9EEpQl+lBHlfMhygbKzwKHtUL57hX16 2dXc22uMVg03Ypk6l7Zs4v6S6YvSlwGRXiWKgSDAcABf9GkCq+3+0p7pp1/sWKl1hC6R XDnDvbraG/6l60hyM6MBOhfJhNG7nq3ms5vzfCeBcQ4crho1rrqFBt6JW43tg9T6cI4Q 5W+A== X-Gm-Message-State: AOJu0YxCnWhKfARLWM/jf9FXSfBoDirZHwBE27EEcKWZaMYksBUyym8U nMz6rGTZIKSE5uRGmYZhy17KZJCgw5qXDLC61Jzw2DFdSvHxCnaE5m/9YhSaOTbzNEH59zzcykW x X-Google-Smtp-Source: AGHT+IGXaWv8aTxBvlvPD1nSo8/S8Xi3+duKPnbA/EmQNDk4gx9bw+lPlBjyZ1KPHe//5pwopZ1W7Q== X-Received: by 2002:a05:6a20:d80d:b0:1cf:3201:c3ad with SMTP id adf61e73a8af0-1cf764aff3dmr14534980637.49.1726311721683; Sat, 14 Sep 2024 04:02:01 -0700 (PDT) Received: from MacBook-Pro-2.local.bytedance.net ([203.208.167.148]) by smtp.gmail.com with ESMTPSA id 41be03b00d2f7-7db4991cfd2sm980043a12.48.2024.09.14.04.01.57 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Sat, 14 Sep 2024 04:02:01 -0700 (PDT) From: Chuang Xu To: qemu-devel@nongnu.org Cc: pbonzini@redhat.com, imammedo@redhat.com, xieyongji@bytedance.com, chaiwen.cc@bytedance.com, zhao1.liu@intel.com, qemu-stable@nongnu.org, Chuang Xu , Guixiong Wei , Yipeng Yin Subject: [PATCH v2] i386/cpu: fixup number of addressable IDs for logical processors in the physical package Date: Sat, 14 Sep 2024 19:01:27 +0800 Message-Id: <20240914110127.67690-1-xuchuangxclwt@bytedance.com> X-Mailer: git-send-email 2.24.3 (Apple Git-128) MIME-Version: 1.0 Received-SPF: pass client-ip=2607:f8b0:4864:20::52a; envelope-from=xuchuangxclwt@bytedance.com; helo=mail-pg1-x52a.google.com X-Spam_score_int: -15 X-Spam_score: -1.6 X-Spam_bar: - X-Spam_report: (-1.6 / 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, FROM_LOCAL_NOVOWEL=0.5, HK_RANDOM_ENVFROM=0.001, HK_RANDOM_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable 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+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org When QEMU is started with: -cpu host,migratable=on,host-cache-info=on,l3-cache=off -smp 180,sockets=2,dies=1,cores=45,threads=2 Execute "cpuid -1 -l 1 -r" in guest, we'll get: eax=0x000806f8 ebx=0x465a0800 ecx=0xfffaba1f edx=0x3fa9fbff CPUID.01H.EBX[23:16] is 90, while the expected value is 128. Execute "cpuid -1 -l 4 -r" in guest, we'll get: eax=0xfc004121 ebx=0x02c0003f ecx=0x0000003f edx=0x00000000 CPUID.04H.EAX[31:26] is 63, which is as expected. As (1+CPUID.04H.EAX[31:26]) round up to the nearest power-of-2 integer, we'd beter round up CPUID.01H.EBX[23:16] to the nearest power-of-2 integer too. Otherwise we may encounter unexpected results in guest. For example, when QEMU is started with CLI above and xtopology is disabled, guest kernel 5.15.120 uses CPUID.01H.EBX[23:16]/(1+CPUID.04H.EAX[31:26]) to calculate threads-per-core in detect_ht(). Then guest will get "90/(1+63)=1" as the result, even though theads-per-core should actually be 2. So let us round up CPUID.01H.EBX[23:16] to the nearest power-of-2 integer to solve the unexpected result. Signed-off-by: Guixiong Wei Signed-off-by: Yipeng Yin Signed-off-by: Chuang Xu --- target/i386/cpu.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 4c2e6f3a71..24d60ead9e 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -261,6 +261,12 @@ static uint32_t max_thread_ids_for_cache(X86CPUTopoInfo *topo_info, return num_ids - 1; } +static uint32_t max_thread_number_in_package(X86CPUTopoInfo *topo_info) +{ + uint32_t num_threads = 1 << apicid_pkg_offset(topo_info); + return num_threads; +} + static uint32_t max_core_ids_in_package(X86CPUTopoInfo *topo_info) { uint32_t num_cores = 1 << (apicid_pkg_offset(topo_info) - @@ -6417,7 +6423,7 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count, } *edx = env->features[FEAT_1_EDX]; if (threads_per_pkg > 1) { - *ebx |= threads_per_pkg << 16; + *ebx |= max_thread_number_in_package(&topo_info) << 16; *edx |= CPUID_HT; } if (!cpu->enable_pmu) {