From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.13]) (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 02151344DA4 for ; Wed, 28 Jan 2026 23:17:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.13 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769642265; cv=none; b=A6sAeHj6aPf18DYklZO2xGox8wm+WCVXghUF3rUVi+iukOcgATTieXOH3F4LFn6tSfNyf8VhqlggQuyy2Geynmic6Osgm/wg4+Q3FefbdclWjVoUpDl4p/DlC5wu9CazZ1OXUEV4vrXLgv+dmIkbJe6pUdWw5qMJICkHxWTJ4EI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769642265; c=relaxed/simple; bh=tFX4i3T29aS2SR3Yr9A5LhqF7R5HWjkcRb3UIujv1eE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Qb9BaWaA1BynzZA7CEufDcG0uQOAFQoLtFjLPcXTCPCBAgHvI2FRdE708OWO/GvShINpJSKu/QprgSntzBjmLc6mOk9H6x3n1KoA37vDFUSgXinhMkioFmPq3Lx0R/wErkcGZ3V0tuVW1GwPVqCMrn82cBaYNFZIYBXe7OzB1BM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=bLCX7qTd; arc=none smtp.client-ip=192.198.163.13 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="bLCX7qTd" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1769642263; x=1801178263; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=tFX4i3T29aS2SR3Yr9A5LhqF7R5HWjkcRb3UIujv1eE=; b=bLCX7qTdECGpkCeM6Rs/tGyOc6Vj2HVxrwlzZ0GlozvoHfE5k5TucMZI qSy8pqcZUWck+wWxww5jCOWdAY3G/j7ZDKZXlBmhncuRJnPBRnGmUMPKD 3wMHInlsivS46aBE4eYSVx5Q9jdspNw8ZaVvjEsh5j0v9OWkXHphxGQ4v 2PumDd34wxKOdYTa6dMHXPSC7w5lIIk4zTl96DAjANeRExYxw2oyD4zVy rCW1FwtmD0FF6PkV+wIr08Xwid9RnmI9kZthSHSZgq3ZfDyJchI42FoDX Qs2qnbbGmLA4qpVI/InXy29/2GTMEnASONrHKerOqGv9vegymiAxeAdKs A==; X-CSE-ConnectionGUID: T0IqgxsiRXyxCNSg3f425Q== X-CSE-MsgGUID: 5nQfq6t0RDKYSJPbsJobjA== X-IronPort-AV: E=McAfee;i="6800,10657,11685"; a="73462338" X-IronPort-AV: E=Sophos;i="6.21,258,1763452800"; d="scan'208";a="73462338" Received: from fmviesa007.fm.intel.com ([10.60.135.147]) by fmvoesa107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Jan 2026 15:17:41 -0800 X-CSE-ConnectionGUID: eFMJHCByREqk9Vkmu5E7eA== X-CSE-MsgGUID: baSQ/vM4SuSE2jwU1xiMYg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,258,1763452800"; d="scan'208";a="208001782" Received: from 9cc2c43eec6b.jf.intel.com ([10.54.77.43]) by fmviesa007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Jan 2026 15:17:41 -0800 From: Zide Chen To: qemu-devel@nongnu.org, kvm@vger.kernel.org, Paolo Bonzini , Zhao Liu , Peter Xu , Fabiano Rosas Cc: Xiaoyao Li , Dongli Zhang , Dapeng Mi , Zide Chen Subject: [PATCH V2 08/11] target/i386: Clean up LBR format handling Date: Wed, 28 Jan 2026 15:09:45 -0800 Message-ID: <20260128231003.268981-9-zide.chen@intel.com> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260128231003.268981-1-zide.chen@intel.com> References: <20260128231003.268981-1-zide.chen@intel.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Since the lbr-fmt property is masked with PERF_CAP_LBR_FMT in DEFINE_PROP_UINT64_CHECKMASK(), there is no need to explicitly validate user-requested lbr-fmt values. The PMU feature is only supported when running under KVM, so initialize cpu->lbr_fmt in kvm_cpu_instance_init(). Use -1 as the default lbr-fmt, rather than initializing it with ~PERF_CAP_LBR_FMT, which is misleading as it suggests a semantic relationship that does not exist. Rename requested_lbr_fmt to a more generic guest_fmt. When lbr-fmt is not specified and cpu->migratable is false, the guest lbr_fmt value is not user-requested. Signed-off-by: Zide Chen --- V2: - New patch. target/i386/cpu.c | 18 ++++++------------ target/i386/kvm/kvm-cpu.c | 2 ++ 2 files changed, 8 insertions(+), 12 deletions(-) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index f2c83b4f259c..09180c718d58 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -9788,7 +9788,7 @@ static void x86_cpu_realizefn(DeviceState *dev, Error **errp) X86CPUClass *xcc = X86_CPU_GET_CLASS(dev); CPUX86State *env = &cpu->env; Error *local_err = NULL; - unsigned requested_lbr_fmt; + unsigned guest_fmt; if (!kvm_enabled()) cpu->enable_pmu = false; @@ -9828,11 +9828,7 @@ static void x86_cpu_realizefn(DeviceState *dev, Error **errp) * Override env->features[FEAT_PERF_CAPABILITIES].LBR_FMT * with user-provided setting. */ - if (cpu->lbr_fmt != ~PERF_CAP_LBR_FMT) { - if ((cpu->lbr_fmt & PERF_CAP_LBR_FMT) != cpu->lbr_fmt) { - error_setg(errp, "invalid lbr-fmt"); - return; - } + if (cpu->lbr_fmt != -1) { env->features[FEAT_PERF_CAPABILITIES] &= ~PERF_CAP_LBR_FMT; env->features[FEAT_PERF_CAPABILITIES] |= cpu->lbr_fmt; } @@ -9841,9 +9837,8 @@ static void x86_cpu_realizefn(DeviceState *dev, Error **errp) * vPMU LBR is supported when 1) KVM is enabled 2) Option pmu=on and * 3)vPMU LBR format matches that of host setting. */ - requested_lbr_fmt = - env->features[FEAT_PERF_CAPABILITIES] & PERF_CAP_LBR_FMT; - if (requested_lbr_fmt && kvm_enabled()) { + guest_fmt = env->features[FEAT_PERF_CAPABILITIES] & PERF_CAP_LBR_FMT; + if (guest_fmt) { uint64_t host_perf_cap = x86_cpu_get_supported_feature_word(NULL, FEAT_PERF_CAPABILITIES); unsigned host_lbr_fmt = host_perf_cap & PERF_CAP_LBR_FMT; @@ -9852,10 +9847,10 @@ static void x86_cpu_realizefn(DeviceState *dev, Error **errp) error_setg(errp, "vPMU: LBR is unsupported without pmu=on"); return; } - if (requested_lbr_fmt != host_lbr_fmt) { + if (guest_fmt != host_lbr_fmt) { error_setg(errp, "vPMU: the lbr-fmt value (0x%x) does not match " "the host value (0x%x).", - requested_lbr_fmt, host_lbr_fmt); + guest_fmt, host_lbr_fmt); return; } } @@ -10279,7 +10274,6 @@ static void x86_cpu_initfn(Object *obj) object_property_add_alias(obj, "sse4_2", obj, "sse4.2"); object_property_add_alias(obj, "hv-apicv", obj, "hv-avic"); - cpu->lbr_fmt = ~PERF_CAP_LBR_FMT; object_property_add_alias(obj, "lbr_fmt", obj, "lbr-fmt"); if (xcc->model) { diff --git a/target/i386/kvm/kvm-cpu.c b/target/i386/kvm/kvm-cpu.c index 33a8c26bc27c..b4500ab69f82 100644 --- a/target/i386/kvm/kvm-cpu.c +++ b/target/i386/kvm/kvm-cpu.c @@ -231,6 +231,8 @@ static void kvm_cpu_instance_init(CPUState *cs) kvm_cpu_max_instance_init(cpu); } + cpu->lbr_fmt = -1; + kvm_cpu_xsave_init(); } -- 2.52.0