From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.8]) (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 2A2CB1F16B; Tue, 18 Aug 2026 17:41:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.8 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787074890; cv=none; b=F6HmWAyTtLnvcnW1Zggdqz8ugzO+/qkohA6HCQVVr3CTJ9qJ3AakXXa3J22eU1r0IkxH8Ktv03CWArI43eeeaE7ZNT2RYZ1ivhJ4EOGOYsjLQE3zYIG1xcAqk6AGh8oW2NUaNq4SBiCEZP/Kle5HPYyjvaREGzGvFhZAAobSGBw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787074890; c=relaxed/simple; bh=Tg8UHYuXd31LqWrkSnt/pKJV1BiDMsc5sKEQ47+w8mQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=HImvarQb56drjVlelrjm0Xukgo0yW5EJx0+eWfcYb2sC8QXReRdkzJ2vS8nv0gDV7ApR2DZgQlpdjUFfRBSiCWkBhUBZ/2MutcPh2XIEAtmxwTY5g0E7jfdNgu5HCMYUGG07+nWoGcQMLBd+4XhX39kkIcX3BkmoUs10t2GnZUE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=pass smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=XUVNg+Yr; arc=none smtp.client-ip=192.198.163.8 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass 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="XUVNg+Yr" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1787074888; x=1818610888; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=Tg8UHYuXd31LqWrkSnt/pKJV1BiDMsc5sKEQ47+w8mQ=; b=XUVNg+YrOXXrcD/t8NMOkCIbxS0BoTVCduJtzII+vW39xx5YjWRSFRSu siXyizGNAFKam9x4AEGU0d8AOY/ecIpU30vxxqaGxms0FlPFhUEA91Z2w WbYUqOJ6H0OxyE9DaA6vQRMdqg41+tI/gbBeYf/x22RUl6cTp2GUfwkMr g3VoBlDR3z9M7vXuRCWKS2K6TvKoBKWgyUS3W1QwjpeGewN3/TXtX/Q7q jNuNsvrKDHY5qlxk/0SDxrjiofZoMSwJrSYXqGHlrqESseSMCWD+5h8u8 KpIUVixsRAF3+yt3jptraSoaSQxgjhyfzTre3AFfifKauCdUhmw/FrSsx g==; X-CSE-ConnectionGUID: InrDCGq7Q+eJI92idvW4jg== X-CSE-MsgGUID: JtpgXVAbT9ilj1+OpOJbYA== X-IronPort-AV: E=McAfee;i="6800,10657,11879"; a="105110342" X-IronPort-AV: E=Sophos;i="6.25,230,1779174000"; d="scan'208";a="105110342" Received: from fmviesa007.fm.intel.com ([10.60.135.147]) by fmvoesa102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Aug 2026 10:41:27 -0700 X-CSE-ConnectionGUID: IhCWEYcAQvWxx+TzgYeovA== X-CSE-MsgGUID: zsFWAiZJRfCVFQ7WoWPO4w== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.25,230,1779174000"; d="scan'208";a="262021727" Received: from tassilo.jf.intel.com (HELO tassilo) ([10.54.38.190]) by fmviesa007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Aug 2026 10:41:26 -0700 Date: Tue, 18 Aug 2026 10:41:25 -0700 From: Andi Kleen To: Zide Chen Cc: Sean Christopherson , Paolo Bonzini , kvm@vger.kernel.org, Jim Mattson , linux-kernel@vger.kernel.org, Mingwei Zhang , Das Sandipan , Shukla Manali , Dapeng Mi , Xudong Hao Subject: Re: [PATCH v8 7/8] KVM: x86/pmu: Emulate RDPMC on performance metrics Message-ID: References: <20260817183143.226156-1-zide.chen@intel.com> <20260817183143.226156-8-zide.chen@intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260817183143.226156-8-zide.chen@intel.com> On Mon, Aug 17, 2026 at 11:31:41AM -0700, Zide Chen wrote: > If the host has the PERF_METRICS capability but it's not present on > the guest, RDPMC interception must be enabled and KVM should inject > an #GP when the guest attempts a PERF_METRICS RDPMC. > > If the guest has PERF_METRICS but RDPMC interception is enabled for > other reasons, KVM needs to emulate RDPMC with type 0x2000. > > For simplicity, Metrics Clear Mode is not supported. But is the bit cleared in PERF_CAPABILITIES? And would the enable bit fault? It would be better to just support it, metrics clear is actually useful. -Andi