From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="JH+vjFaL" Received: from mgamail.intel.com (mgamail.intel.com [134.134.136.126]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DF630CB; Mon, 4 Dec 2023 14:04:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1701727498; x=1733263498; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=4hdFpwxoWy6g4uIjhOcxul5k6qD6bNS8h15Ws3gqgH0=; b=JH+vjFaLVnZz/4JMSXx/2KeqCaK9k02+rEmd1956KPUzd6gkadDtxOYN Y6HuhjUvteVnpx/4TONiApvoxdODe7Tnk6e8iCS2YhFksBlPqxgJxiVbI /IsGj19BXPlQZzq6aEbiTwMo6IB6B/09oaoXqfX41npmFVKdcDt7Po5kS KXJMRjqwluY+1tP1Umf7IgkGmxjiuz7QoD/yq4RP8Sy/5Bi7t/vdX2tap /kQlwVLZ4lxBzfV6dKRrXmIyFexxj7DDZ/NtezsKy0ncKregveiHyhCw5 zq1S0igAzkbLbl7m4KPpDr4SBC/ouH4mef371QQTV7GVCWMMKClGJbvOT g==; X-IronPort-AV: E=McAfee;i="6600,9927,10914"; a="378831952" X-IronPort-AV: E=Sophos;i="6.04,250,1695711600"; d="scan'208";a="378831952" Received: from fmviesa001.fm.intel.com ([10.60.135.141]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Dec 2023 14:04:58 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.04,250,1695711600"; d="scan'208";a="17325751" Received: from gauravs1-mobl.amr.corp.intel.com (HELO [10.209.53.199]) ([10.209.53.199]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Dec 2023 14:04:57 -0800 Message-ID: <9b221937-42df-4381-b79f-05fb41155f7a@intel.com> Date: Mon, 4 Dec 2023 14:04:56 -0800 Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v15 22/23] x86/mce: Improve error log of kernel space TDX #MC due to erratum Content-Language: en-US To: "Huang, Kai" , "kvm@vger.kernel.org" , "linux-kernel@vger.kernel.org" Cc: "Williams, Dan J" , "x86@kernel.org" , "Luck, Tony" , "david@redhat.com" , "bagasdotme@gmail.com" , "ak@linux.intel.com" , "kirill.shutemov@linux.intel.com" , "mingo@redhat.com" , "seanjc@google.com" , "pbonzini@redhat.com" , "tglx@linutronix.de" , "Yamahata, Isaku" , "nik.borisov@suse.com" , "hpa@zytor.com" , "sagis@google.com" , "imammedo@redhat.com" , "peterz@infradead.org" , "bp@alien8.de" , "Brown, Len" , "sathyanarayanan.kuppuswamy@linux.intel.com" , "Huang, Ying" , "rafael@kernel.org" , "Gao, Chao" References: <9e80873fac878aa5d697cbcd4d456d01e1009d1f.1699527082.git.kai.huang@intel.com> From: Dave Hansen Autocrypt: addr=dave.hansen@intel.com; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 12/4/23 13:00, Huang, Kai wrote: >> tl;dr: I think even looking a #MC on the PAMT after the kvm module is >> removed is a fool's errand. > Sorry I wasn't clear enough. KVM actually turns off VMX when it destroys the > last VM, so the KVM module doesn't need to be removed to turn off VMX. I used > "KVM can be unloaded" as an example to explain the PAMT can be working when VMX > is off. Can't we just fix this by having KVM do an "extra" hardware_enable_all() before initializing the TDX module? It's not wrong to say that TDX is a KVM user. If KVm wants 'kvm_usage_count' to go back to 0, it can shut down the TDX module. Then there's no PAMT to worry about. The shutdown would be something like: 1. TDX module shutdown 2. Deallocate/Convert PAMT 3. vmxoff Then, no SEAMCALL failure because of vmxoff can cause a PAMT-induced #MC to be missed.