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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?q?lepfAPdlPFqIITT/0MkUSRKXz0Dy?= =?utf-8?q?E3dBqreyySC+C4P3ZDJJ+mMJcC/15otiNmg0DOdLmPLg69cZIfomHzAw16imjW7WP?= =?utf-8?q?eemcvExGp02uk2/XYRq091YG7A1NdThKwwvRHHRY90FrvAAhh65YMgTjxYJjuyEIR?= =?utf-8?q?b6X4vH8qeB8cDFADi9c5ZacWdMKCiEKUc6I9gaav10QEpJFVPaFF3h3I8uU/9hQFL?= =?utf-8?q?p2yAdtvWIBDzrTZOpWGd2y06SoRiXZ+9OOrJ2K6jFOWre+cDOYwPe5U7B47wqLK7X?= =?utf-8?q?f1IztFji3XkEz06TBFFX0WWjlzcufsgfVsXXNjZ9BnQPWzmE1kh6VH/p6j0TorOPi?= =?utf-8?q?NXiJR8MOvCYy8DaKj6cZNLjuHjFvQUb+Fh94MxGj2Bo3LIXOb3fvdWpBGjE5vt1p7?= =?utf-8?q?ymc+wGi6i9i1A+7hVyXvBbNe4cb4rk6p5FP2bpeNJqddOf2CTQ0Pit3+WIgkIUvxX?= =?utf-8?q?0PIxx/lqMFt3MOCVwwMogDwyVxGSja8jZ78H6V8oTNVfx1vadvl+mfAZiOWqW1PNz?= =?utf-8?q?BYFf8VlVn0sW8eZVGQTrD5srNhFWwINfDMDEaJzIL5dg+RrhP//TSmajlrTNTM/lb?= =?utf-8?q?DM/NB4G9DkX4PEIpxsiZ4l0pf7oO0ugZXBL+4k9AmMVpmObdm+gSXu7atKv4bavR5?= =?utf-8?q?ENPkJAqGIc58RR1TbNM2sC+zLocCyThoTRipP70OUFMTDLuUeJkvNS6CLtRe+APO1?= =?utf-8?q?WR4pYQdDi1iORhPICgGXgbI6yGeazQ3GFdsXhL7vUXWXx4QMR0uwY8mjUf6Dy4qva?= =?utf-8?q?x5MBGNzdoJalES9MEXRtU7BDhJ4+LaX1HgR8a9etc6tthnUh2LPyudOqFYRihtkkq?= =?utf-8?q?XbHJFHfoDFJ+LNPYNbWqPlyZkLjixqnNw9N4JiouNUZqhoftCTQrUqsK9ZCSaSJNs?= =?utf-8?q?9xtTC3bj2R+fVu45Z3GzHTU2vPTJK5C8SKZtdmi9jSxG7aEODz3TAoI1k7oXl6693?= =?utf-8?q?hP2osj48+rZXpTGR2MNW/uZnsyFrTcxpGT4GrZpWD5g4JAx5Uaotp4BUsuiLR+inQ?= =?utf-8?q?G54TwSQw+1H9xfoi4Bn6W7LfHyfF9N1vJCFwmpe8SsHMInMvPCtRC0qcfZ2AOnL/j?= =?utf-8?q?GPxLZ9Zr7rBfXk1e+ndX56BOOuxDjHEvDFoOvSsaaLH63ik2oMxhI4EQJ4ePWzboM?= =?utf-8?q?N+wepdz3EzbhMDgSql3wkr/fnTcU+g1o1XZBq0z1SO6jo58eIRHOSRA/qY+6m7EBe?= =?utf-8?q?qlexcopeLWjP7Xq7yD3V7UgEa3Yn/yvE7bqy6qr7BvwhV/dyFXG5svxEWqhOLJbeR?= =?utf-8?q?cVcLA6VG7gDtg7OIuT7ZVbnv+Iyxuu07Ke0BTc2lx3okvyLRRYAZwm8FrSmrJ9mxE?= =?utf-8?q?9pQdPMkyk8B8Pujc7QVZODRG2q7QCIxtv/KhVai7DzEmw9qD9D9MU222JQ+fYNkq5?= =?utf-8?q?GeX+mA71fCZr08ScOUe50KEwLC5VqriAe5qAuDEjU5VoQNA2RNVEHaC3yy5TTgAr+?= =?utf-8?q?y3s1bGiZyPDofThyyL/Z3JkYBysWOoirHTbpDD4X0GuNagWJIoTl8ruQrOFxv+Zdi?= =?utf-8?q?kDa0RHh4T4Sxw0TnoyRJyVqiopD1qu8t+/bSerdUjr/nBZyZZc2LoLg=3D?= X-OriginatorOrg: suse.com X-MS-Exchange-CrossTenant-Network-Message-Id: 6714bd0f-aad0-49b6-152b-08d9b655b3be X-MS-Exchange-CrossTenant-AuthSource: VI1PR04MB5600.eurprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 03 Dec 2021 12:09:05.4709 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: f7a17af6-1c5c-4a36-aa8b-f5be247aa4ba X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: UYlXlLyJ52J+Z6KoH2Buu3WJXzZSD5N1A1Yc/eEixMJvP1m3ZoD5c+5k76h8Vhq8/0UpN23TqkX88z6t8lA1xA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: VI1PR04MB4191 The 64-bit form forces %ecx to 0 while the 32-bit one so far didn't - it only ended up that way when "pv_context" is zero. While presently no leaf queried by callers has separate subleaves, let's avoid chancing it. While there - replace references to operands by number, - relax constraints where possible, - limit PUSH/POP to just the registers not also used as input, all where applicable also for the 64-bit variant. Signed-off-by: Jan Beulich Reviewed-by: Anthony PERARD --- I'm pretty sure %edx also wouldn't need to be subject to PUSH/POP here, but I didn't want to go more "against" the comment than obviously justifiable by the input registers used. In fact I've observed gcc to pick %edx for putting "pv_context" in. --- a/tools/misc/xen-detect.c +++ b/tools/misc/xen-detect.c @@ -52,17 +52,19 @@ static void cpuid(uint32_t idx, uint32_t #ifdef __i386__ /* Use the stack to avoid reg constraint failures with some gcc flags */ asm volatile ( - "push %%eax; push %%ebx; push %%ecx; push %%edx\n\t" - "test %1,%1 ; jz 1f ; ud2a ; .ascii \"xen\" ; 1: cpuid\n\t" - "mov %%eax,(%2); mov %%ebx,4(%2)\n\t" - "mov %%ecx,8(%2); mov %%edx,12(%2)\n\t" - "pop %%edx; pop %%ecx; pop %%ebx; pop %%eax\n\t" - : : "a" (idx), "c" (pv_context), "S" (regs) : "memory" ); + "push %%ebx; push %%edx\n\t" + "test %[pv],%[pv] ; jz 1f ; ud2a ; .ascii \"xen\" ; 1: cpuid\n\t" + "mov %%eax,(%[regs]); mov %%ebx,4(%[regs])\n\t" + "mov %%ecx,8(%[regs]); mov %%edx,12(%[regs])\n\t" + "pop %%edx; pop %%ebx\n\t" + : "+a" (idx), "=c" (idx /* dummy */) + : "c" (0), [pv] "r" (pv_context), [regs] "SD" (regs) + : "memory" ); #else asm volatile ( - "test %5,%5 ; jz 1f ; ud2a ; .ascii \"xen\" ; 1: cpuid\n\t" + "test %[pv],%[pv] ; jz 1f ; ud2a ; .ascii \"xen\" ; 1: cpuid\n\t" : "=a" (regs[0]), "=b" (regs[1]), "=c" (regs[2]), "=d" (regs[3]) - : "0" (idx), "1" (pv_context), "2" (0) ); + : "0" (idx), "2" (0), [pv] "r" (pv_context) ); #endif }