tree: https://git.kernel.org/pub/scm/linux/kernel/git/luto/linux.git x86/fixes head: cbf296087190a1b9172fe419a5df194302829bf7 commit: cbf296087190a1b9172fe419a5df194302829bf7 [1/1] x86/kvm: Handle async page faults directly through do_page_fault() config: x86_64-defconfig (attached as .config) compiler: gcc-7 (Debian 7.5.0-5) 7.5.0 reproduce: git checkout cbf296087190a1b9172fe419a5df194302829bf7 # save the attached .config to linux build tree make ARCH=x86_64 If you fix the issue, kindly add following tag Reported-by: kbuild test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): arch/x86/mm/fault.c: In function 'do_page_fault': if (kvm_handle_async_pf(regs, hw_error_code, address)) ^~~~~~~~~~~~~~~~~~~ cc1: some warnings being treated as errors vim +/kvm_handle_async_pf +1525 arch/x86/mm/fault.c 1503 1504 dotraplinkage void 1505 do_page_fault(struct pt_regs *regs, unsigned long hw_error_code, 1506 unsigned long address) 1507 { 1508 prefetchw(&current->mm->mmap_sem); 1509 /* 1510 * KVM has two types of events that are, logically, interrupts, but 1511 * are unfortunately delivered using the #PF vector. These events are 1512 * "you just accessed valid memory, but the host doesn't have it right 1513 * not, so I'll put you to sleep if you continue" and "that memory 1514 * you tried to access earlier is available now." 1515 * 1516 * We are relying on the interrupted context being sane (valid 1517 * RSP, relevant locks not held, etc.), which is fine as long as 1518 * the the interrupted context had IF=1. We are also relying on 1519 * the KVM async pf type field and CR2 being read consistently 1520 * instead of getting values from real and async page faults 1521 * mixed up. 1522 * 1523 * Fingers crossed. 1524 */ --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org