From patchwork Mon Jan 8 08:27:26 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhao Liu X-Patchwork-Id: 13513117 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.9]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A1EF6BE5B for ; Mon, 8 Jan 2024 08:15:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="W/uNkvxS" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1704701728; x=1736237728; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=3zgY2YTpEdwKz5M6nhH81emF+Pu/aNmqeKvqFmSQRK8=; b=W/uNkvxSPqJtOufGcylalkz1aQTl1C+iUErsLgQ5rcS1aOZYJy9giFfW yMU1zPX0/0S99Dh5cm3fLDWCrjGXLor+iW5oeArcy7ya96Jkv7oNVoBEQ iAlpNshBNFDCuo3rvVfg1grkSIqBfeRotI9wDDjeucvmhjn9Ku3jmEUC5 TsAE7FsnWPW661HVbfQoTlzjqEhwcVQOVKo3YIaLCnGKrymoBDbWeD0PN x1wMmcf45Pmm7ljRB9psfd7D46V4t+s/+qh7sKibFXy+bETDpwxUxGELG sVejAIP65PIZT5JdeicO6lxHAS202CY706eXejk5GGKpCPmfkGcDH2Sp+ Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10946"; a="16420075" X-IronPort-AV: E=Sophos;i="6.04,340,1695711600"; d="scan'208";a="16420075" Received: from fmviesa002.fm.intel.com ([10.60.135.142]) by orvoesa101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Jan 2024 00:15:28 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.04,340,1695711600"; d="scan'208";a="15850439" Received: from liuzhao-optiplex-7080.sh.intel.com ([10.239.160.36]) by fmviesa002.fm.intel.com with ESMTP; 08 Jan 2024 00:15:24 -0800 From: Zhao Liu To: Eduardo Habkost , Marcel Apfelbaum , "Michael S . Tsirkin" , Richard Henderson , Paolo Bonzini , Marcelo Tosatti Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org, Zhenyu Wang , Zhuocheng Ding , Zhao Liu , Babu Moger , Yongwei Ma Subject: [PATCH v7 15/16] i386: Use offsets get NumSharingCache for CPUID[0x8000001D].EAX[bits 25:14] Date: Mon, 8 Jan 2024 16:27:26 +0800 Message-Id: <20240108082727.420817-16-zhao1.liu@linux.intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240108082727.420817-1-zhao1.liu@linux.intel.com> References: <20240108082727.420817-1-zhao1.liu@linux.intel.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Zhao Liu The commit 8f4202fb1080 ("i386: Populate AMD Processor Cache Information for cpuid 0x8000001D") adds the cache topology for AMD CPU by encoding the number of sharing threads directly. From AMD's APM, NumSharingCache (CPUID[0x8000001D].EAX[bits 25:14]) means [1]: The number of logical processors sharing this cache is the value of this field incremented by 1. To determine which logical processors are sharing a cache, determine a Share Id for each processor as follows: ShareId = LocalApicId >> log2(NumSharingCache+1) Logical processors with the same ShareId then share a cache. If NumSharingCache+1 is not a power of two, round it up to the next power of two. From the description above, the calculation of this field should be same as CPUID[4].EAX[bits 25:14] for Intel CPUs. So also use the offsets of APIC ID to calculate this field. [1]: APM, vol.3, appendix.E.4.15 Function 8000_001Dh--Cache Topology Information Signed-off-by: Zhao Liu Reviewed-by: Babu Moger Tested-by: Babu Moger Tested-by: Yongwei Ma Acked-by: Michael S. Tsirkin --- Changes since v3: * Rewrite the subject. (Babu) * Delete the original "comment/help" expression, as this behavior is confirmed for AMD CPUs. (Babu) * Rename "num_apic_ids" (v3) to "num_sharing_cache" to match spec definition. (Babu) Changes since v1: * Rename "l3_threads" to "num_apic_ids" in encode_cache_cpuid8000001d(). (Yanan) * Add the description of the original commit and add Cc. --- target/i386/cpu.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index b23e8190dc68..8a4d72f6f760 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -483,7 +483,7 @@ static void encode_cache_cpuid8000001d(CPUCacheInfo *cache, uint32_t *eax, uint32_t *ebx, uint32_t *ecx, uint32_t *edx) { - uint32_t l3_threads; + uint32_t num_sharing_cache; assert(cache->size == cache->line_size * cache->associativity * cache->partitions * cache->sets); @@ -492,13 +492,11 @@ static void encode_cache_cpuid8000001d(CPUCacheInfo *cache, /* L3 is shared among multiple cores */ if (cache->level == 3) { - l3_threads = topo_info->modules_per_die * - topo_info->cores_per_module * - topo_info->threads_per_core; - *eax |= (l3_threads - 1) << 14; + num_sharing_cache = 1 << apicid_die_offset(topo_info); } else { - *eax |= ((topo_info->threads_per_core - 1) << 14); + num_sharing_cache = 1 << apicid_core_offset(topo_info); } + *eax |= (num_sharing_cache - 1) << 14; assert(cache->line_size > 0); assert(cache->partitions > 0);