From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E8668C433E0 for ; Mon, 1 Feb 2021 05:04:18 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 3C8B864E2A for ; Mon, 1 Feb 2021 05:04:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3C8B864E2A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:53134 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1l6RNp-0002RM-Af for qemu-devel@archiver.kernel.org; Mon, 01 Feb 2021 00:04:17 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:39114) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l6RMN-0001Wj-PX for qemu-devel@nongnu.org; Mon, 01 Feb 2021 00:02:47 -0500 Received: from mga01.intel.com ([192.55.52.88]:15891) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l6RML-0003NA-S1 for qemu-devel@nongnu.org; Mon, 01 Feb 2021 00:02:47 -0500 IronPort-SDR: xJ4Sho8vQCjMpLe9+JT2O6HQNn3H0DRaG/yfZPaC5tIa3DHdKHVq3NIzdHtwGyD3miuXy1W9Jk 4Ewzw+6rGGTw== X-IronPort-AV: E=McAfee;i="6000,8403,9881"; a="199523990" X-IronPort-AV: E=Sophos;i="5.79,391,1602572400"; d="scan'208";a="199523990" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Jan 2021 21:01:22 -0800 IronPort-SDR: TrJipL50C9kzAIHzlR6VRHMU+k3JBIzUgZPSrGloCmBk8kyzDXXVon5b/t8P8fMHZjTytVEC/3 Xul0MrHzS9dA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.79,391,1602572400"; d="scan'208";a="390690218" Received: from clx-ap-likexu.sh.intel.com ([10.239.48.108]) by orsmga008.jf.intel.com with ESMTP; 31 Jan 2021 21:01:21 -0800 From: Like Xu To: Paolo Bonzini , Richard Henderson , Eduardo Habkost Subject: [PATCH v2 2/2] target/i386: add kvm_exact_match_flags to FeatureWordInfo Date: Mon, 1 Feb 2021 12:54:53 +0800 Message-Id: <20210201045453.240258-2-like.xu@linux.intel.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210201045453.240258-1-like.xu@linux.intel.com> References: <20210201045453.240258-1-like.xu@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Received-SPF: none client-ip=192.55.52.88; envelope-from=like.xu@linux.intel.com; helo=mga01.intel.com X-Spam_score_int: -68 X-Spam_score: -6.9 X-Spam_bar: ------ X-Spam_report: (-6.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_HI=-5, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_NONE=0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Eduardo has a suggestion: instead of hardcoding the PERF_CAPABILITIES rules in this loop, this could become a FeatureWordInfo field. It would be very useful for other features like intel-pt, where we need some bits to match the host too. Suggested-by: Eduardo Habkost Signed-off-by: Like Xu --- target/i386/cpu.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 80a5d3f0c2..8eaa5879ea 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -708,6 +708,8 @@ typedef struct FeatureWordInfo { uint64_t migratable_flags; /* Feature flags known to be migratable */ /* Features that shouldn't be auto-enabled by "-cpu host" */ uint64_t no_autoenable_flags; + /* Bits that must match host exactly when using KVM */ + uint64_t kvm_exact_match_flags; } FeatureWordInfo; static FeatureWordInfo feature_word_info[FEATURE_WORDS] = { @@ -1147,6 +1149,11 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS] = { .msr = { .index = MSR_IA32_PERF_CAPABILITIES, }, + /* + * KVM is not able to emulate a VCPU with LBR_FMT different + * from the host, so LBR_FMT must match the host exactly. + */ + .kvm_exact_match_flags = PERF_CAP_LBR_FMT, }, [FEAT_VMX_PROCBASED_CTLS] = { @@ -6500,16 +6507,18 @@ static void x86_cpu_filter_features(X86CPU *cpu, bool verbose) } for (w = 0; w < FEATURE_WORDS; w++) { + FeatureWordInfo *fi = &feature_word_info[w]; + uint64_t match_flags = fi->kvm_exact_match_flags; uint64_t host_feat = x86_cpu_get_supported_feature_word(w, false); uint64_t requested_features = env->features[w]; uint64_t unavailable_features = requested_features & ~host_feat; - if (kvm_enabled() && w == FEAT_PERF_CAPABILITIES && - (requested_features & PERF_CAP_LBR_FMT)) { - if ((host_feat & PERF_CAP_LBR_FMT) != - (requested_features & PERF_CAP_LBR_FMT)) { - unavailable_features |= PERF_CAP_LBR_FMT; - } + if (kvm_enabled() && match_flags) { + uint64_t mismatches = (requested_features & match_flags) && + (requested_features ^ host_feat) & match_flags; + mark_unavailable_features(cpu, w, + mismatches, "feature doesn't match host"); + unavailable_features &= ~match_flags; } mark_unavailable_features(cpu, w, unavailable_features, prefix); } -- 2.29.2