From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [134.134.136.20]) (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 7C9E729A9 for ; Fri, 13 Oct 2023 15:07:18 +0000 (UTC) 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="G4vDb2Cz" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1697209638; x=1728745638; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to; bh=I9ejgnkc4T1U17W9HiaslETujXXaw9iMHZTTGR4wj6g=; b=G4vDb2CzZ71tGFB6sSYxMaJuq9K8nlOLVU8VTwpPM1suHt92xtvmmHP5 +DcD888sV5t/VO04NQ6NfmUZm0uh4BjBlhhlkWXENuO6MyKbzre25OUlK /+hWYVz2pv3+k7kIeADfCxg0ZOxh+bgI8HGdSfAfg8YhCI0rzRuSwSxtX 5nXyT7+hsKkjeEkdetiW1iznJj1kZxk8Yrd8MCF182YbiBXxbs6/+WxYW UbS9KpJ7SUxE/IdmJ+/wQ1wCkPBwr/cQRi4VNM3huso/EqO9d9E13j30z OaClusQo6tkNC+YxhC73MwX4Rwlx0Jy4Z+I3QbYbXDPe7IP1D9EQTy9UB A==; X-IronPort-AV: E=McAfee;i="6600,9927,10862"; a="375552699" X-IronPort-AV: E=Sophos;i="6.03,222,1694761200"; d="scan'208";a="375552699" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Oct 2023 08:06:00 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10862"; a="704676500" X-IronPort-AV: E=Sophos;i="6.03,222,1694761200"; d="scan'208";a="704676500" Received: from marinjul-mobl.amr.corp.intel.com (HELO [10.255.231.41]) ([10.255.231.41]) by orsmga003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Oct 2023 08:06:00 -0700 Content-Type: multipart/mixed; boundary="------------4QAAwMnZ7myaM0IpTAN94Ja9" Message-ID: <532fd5c3-dddb-4503-9b81-31c3d07a7119@intel.com> Date: Fri, 13 Oct 2023 08:05:54 -0700 Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 01/12] x86/mce: Fix hw MCE injection feature detection Content-Language: en-US To: isaku.yamahata@intel.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org Cc: isaku.yamahata@gmail.com, Michael Roth , Paolo Bonzini , Sean Christopherson , linux-coco@lists.linux.dev, Chao Peng , Smita Koralahalli , Borislav Petkov References: <23c6fa20777498bccd486aedc435eef9af174748.1696926843.git.isaku.yamahata@intel.com> From: Dave Hansen Autocrypt: addr=dave.hansen@intel.com; keydata= xsFNBE6HMP0BEADIMA3XYkQfF3dwHlj58Yjsc4E5y5G67cfbt8dvaUq2fx1lR0K9h1bOI6fC oAiUXvGAOxPDsB/P6UEOISPpLl5IuYsSwAeZGkdQ5g6m1xq7AlDJQZddhr/1DC/nMVa/2BoY 2UnKuZuSBu7lgOE193+7Uks3416N2hTkyKUSNkduyoZ9F5twiBhxPJwPtn/wnch6n5RsoXsb ygOEDxLEsSk/7eyFycjE+btUtAWZtx+HseyaGfqkZK0Z9bT1lsaHecmB203xShwCPT49Blxz VOab8668QpaEOdLGhtvrVYVK7x4skyT3nGWcgDCl5/Vp3TWA4K+IofwvXzX2ON/Mj7aQwf5W iC+3nWC7q0uxKwwsddJ0Nu+dpA/UORQWa1NiAftEoSpk5+nUUi0WE+5DRm0H+TXKBWMGNCFn c6+EKg5zQaa8KqymHcOrSXNPmzJuXvDQ8uj2J8XuzCZfK4uy1+YdIr0yyEMI7mdh4KX50LO1 pmowEqDh7dLShTOif/7UtQYrzYq9cPnjU2ZW4qd5Qz2joSGTG9eCXLz5PRe5SqHxv6ljk8mb ApNuY7bOXO/A7T2j5RwXIlcmssqIjBcxsRRoIbpCwWWGjkYjzYCjgsNFL6rt4OL11OUF37wL QcTl7fbCGv53KfKPdYD5hcbguLKi/aCccJK18ZwNjFhqr4MliQARAQABzUVEYXZpZCBDaHJp c3RvcGhlciBIYW5zZW4gKEludGVsIFdvcmsgQWRkcmVzcykgPGRhdmUuaGFuc2VuQGludGVs LmNvbT7CwXgEEwECACIFAlQ+9J0CGwMGCwkIBwMCBhUIAgkKCwQWAgMBAh4BAheAAAoJEGg1 lTBwyZKwLZUP/0dnbhDc229u2u6WtK1s1cSd9WsflGXGagkR6liJ4um3XCfYWDHvIdkHYC1t MNcVHFBwmQkawxsYvgO8kXT3SaFZe4ISfB4K4CL2qp4JO+nJdlFUbZI7cz/Td9z8nHjMcWYF IQuTsWOLs/LBMTs+ANumibtw6UkiGVD3dfHJAOPNApjVr+M0P/lVmTeP8w0uVcd2syiaU5jB aht9CYATn+ytFGWZnBEEQFnqcibIaOrmoBLu2b3fKJEd8Jp7NHDSIdrvrMjYynmc6sZKUqH2 I1qOevaa8jUg7wlLJAWGfIqnu85kkqrVOkbNbk4TPub7VOqA6qG5GCNEIv6ZY7HLYd/vAkVY E8Plzq/NwLAuOWxvGrOl7OPuwVeR4hBDfcrNb990MFPpjGgACzAZyjdmYoMu8j3/MAEW4P0z F5+EYJAOZ+z212y1pchNNauehORXgjrNKsZwxwKpPY9qb84E3O9KYpwfATsqOoQ6tTgr+1BR CCwP712H+E9U5HJ0iibN/CDZFVPL1bRerHziuwuQuvE0qWg0+0SChFe9oq0KAwEkVs6ZDMB2 P16MieEEQ6StQRlvy2YBv80L1TMl3T90Bo1UUn6ARXEpcbFE0/aORH/jEXcRteb+vuik5UGY 5TsyLYdPur3TXm7XDBdmmyQVJjnJKYK9AQxj95KlXLVO38lczsFNBFRjzmoBEACyAxbvUEhd GDGNg0JhDdezyTdN8C9BFsdxyTLnSH31NRiyp1QtuxvcqGZjb2trDVuCbIzRrgMZLVgo3upr MIOx1CXEgmn23Zhh0EpdVHM8IKx9Z7V0r+rrpRWFE8/wQZngKYVi49PGoZj50ZEifEJ5qn/H Nsp2+Y+bTUjDdgWMATg9DiFMyv8fvoqgNsNyrrZTnSgoLzdxr89FGHZCoSoAK8gfgFHuO54B lI8QOfPDG9WDPJ66HCodjTlBEr/Cwq6GruxS5i2Y33YVqxvFvDa1tUtl+iJ2SWKS9kCai2DR 3BwVONJEYSDQaven/EHMlY1q8Vln3lGPsS11vSUK3QcNJjmrgYxH5KsVsf6PNRj9mp8Z1kIG qjRx08+nnyStWC0gZH6NrYyS9rpqH3j+hA2WcI7De51L4Rv9pFwzp161mvtc6eC/GxaiUGuH BNAVP0PY0fqvIC68p3rLIAW3f97uv4ce2RSQ7LbsPsimOeCo/5vgS6YQsj83E+AipPr09Caj 0hloj+hFoqiticNpmsxdWKoOsV0PftcQvBCCYuhKbZV9s5hjt9qn8CE86A5g5KqDf83Fxqm/ vXKgHNFHE5zgXGZnrmaf6resQzbvJHO0Fb0CcIohzrpPaL3YepcLDoCCgElGMGQjdCcSQ+Ci FCRl0Bvyj1YZUql+ZkptgGjikQARAQABwsFfBBgBAgAJBQJUY85qAhsMAAoJEGg1lTBwyZKw l4IQAIKHs/9po4spZDFyfDjunimEhVHqlUt7ggR1Hsl/tkvTSze8pI1P6dGp2XW6AnH1iayn yRcoyT0ZJ+Zmm4xAH1zqKjWplzqdb/dO28qk0bPso8+1oPO8oDhLm1+tY+cOvufXkBTm+whm +AyNTjaCRt6aSMnA/QHVGSJ8grrTJCoACVNhnXg/R0g90g8iV8Q+IBZyDkG0tBThaDdw1B2l asInUTeb9EiVfL/Zjdg5VWiF9LL7iS+9hTeVdR09vThQ/DhVbCNxVk+DtyBHsjOKifrVsYep WpRGBIAu3bK8eXtyvrw1igWTNs2wazJ71+0z2jMzbclKAyRHKU9JdN6Hkkgr2nPb561yjcB8 sIq1pFXKyO+nKy6SZYxOvHxCcjk2fkw6UmPU6/j/nQlj2lfOAgNVKuDLothIxzi8pndB8Jju KktE5HJqUUMXePkAYIxEQ0mMc8Po7tuXdejgPMwgP7x65xtfEqI0RuzbUioFltsp1jUaRwQZ MTsCeQDdjpgHsj+P2ZDeEKCbma4m6Ez/YWs4+zDm1X8uZDkZcfQlD9NldbKDJEXLIjYWo1PH hYepSffIWPyvBMBTW2W5FRjJ4vLRrJSUoEfJuPQ3vW9Y73foyo/qFoURHO48AinGPZ7PC7TF vUaNOTjKedrqHkaOcqB185ahG2had0xnFsDPlx5y In-Reply-To: <23c6fa20777498bccd486aedc435eef9af174748.1696926843.git.isaku.yamahata@intel.com> This is a multi-part message in MIME format. --------------4QAAwMnZ7myaM0IpTAN94Ja9 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Isaku, when you report a bug, it would be great to include the folks who authored and worked on the original patch that introduced the bug. I've gone ahead and done that for you here. On 10/10/23 01:35, isaku.yamahata@intel.com wrote: > From: Isaku Yamahata > > When initializing x86 MCE injection framework, it checks if hardware mce > injection is available or not. When it's not available on AMD, set the > boolean variable to false to not use it. The variable is on by default and > the feature is AMD specific based on the code. > > Because the variable is default on, it is true on Intel platform (probably > on other non-AMD x86 platform). It results in unchecked msr access of > MSR_K7_HWCR=0xc0010015 when injecting MCE on Intel platform. (Probably on > other x86 platform.) > > Make the variable of by default, and set the variable on when the hardware > feature is usable. Gah, I'm finding that changelog impenetrable. Here's what's missing: * The entirety of check_hw_inj_possible() is for AMD hardware: X86_FEATURE_SMCA, the MSRs, hw_injection_possible, everything. * Only AMD systems with SMCA support hardware error injection (anything other than "echo sw > /sys/kernel/debug/mce-inject/flags") * That AMD-only restriction is enforced by 'hw_injection_possible' * 'hw_injection_possible' is true by default and only set to false in check_hw_inj_possible() ... the AMD-only code The end result is that everyone except SMCA-enabled AMD systems (Intel included) leaves hw_injection_possible=true. They are free to try and inject hardware errors. If they do, they'll get errors when writing to the MSRs. To fix this, make disable hw_injection_possible by default. Only enable it on SMCA hardware that actually succeeds in ... whatever: wrmsrl_safe(mca_msr_reg(bank, MCA_STATUS), status); rdmsrl_safe(mca_msr_reg(bank, MCA_STATUS), &status); is doing. ... and don't do it at the top of the function. Why bother setting it to true only to disable it a moment later? Do something like the following instead. --------------4QAAwMnZ7myaM0IpTAN94Ja9 Content-Type: text/x-patch; charset=UTF-8; name="amdmce.patch" Content-Disposition: attachment; filename="amdmce.patch" Content-Transfer-Encoding: base64 ZGlmZiAtLWdpdCBhL2FyY2gveDg2L2tlcm5lbC9jcHUvbWNlL2luamVjdC5jIGIvYXJjaC94 ODYva2VybmVsL2NwdS9tY2UvaW5qZWN0LmMKaW5kZXggNGQ4ZDRiY2Y5MTVkLi4wMWVlODg2 ZDg1NDAgMTAwNjQ0Ci0tLSBhL2FyY2gveDg2L2tlcm5lbC9jcHUvbWNlL2luamVjdC5jCisr KyBiL2FyY2gveDg2L2tlcm5lbC9jcHUvbWNlL2luamVjdC5jCkBAIC0zMyw3ICszMyw3IEBA CiAKICNpbmNsdWRlICJpbnRlcm5hbC5oIgogCi1zdGF0aWMgYm9vbCBod19pbmplY3Rpb25f cG9zc2libGUgPSB0cnVlOworc3RhdGljIGJvb2wgaHdfaW5qZWN0aW9uX3Bvc3NpYmxlOwog CiAvKgogICogQ29sbGVjdCBhbGwgdGhlIE1DaV9YWFggc2V0dGluZ3MKQEAgLTc0OCw5ICs3 NDgsMTAgQEAgc3RhdGljIHZvaWQgY2hlY2tfaHdfaW5qX3Bvc3NpYmxlKHZvaWQpCiAJCXJk bXNybF9zYWZlKG1jYV9tc3JfcmVnKGJhbmssIE1DQV9TVEFUVVMpLCAmc3RhdHVzKTsKIAog CQlpZiAoIXN0YXR1cykgewotCQkJaHdfaW5qZWN0aW9uX3Bvc3NpYmxlID0gZmFsc2U7CiAJ CQlwcl93YXJuKCJQbGF0Zm9ybSBkb2VzIG5vdCBhbGxvdyAqaGFyZHdhcmUqIGVycm9yIGlu amVjdGlvbi4iCiAJCQkJIlRyeSB1c2luZyBBUEVJIEVJTkogaW5zdGVhZC5cbiIpOworCQl9 IGVsc2UgeworCQkJaHdfaW5qZWN0aW9uX3Bvc3NpYmxlID0gdHJ1ZTsKIAkJfQogCiAJCXRv Z2dsZV9od19tY2VfaW5qZWN0KGNwdSwgZmFsc2UpOwo= --------------4QAAwMnZ7myaM0IpTAN94Ja9--