FYI, we noticed the following commit (built with gcc-7):

commit: aec3011ae9800585e8e218ca33884a66db156da1 ("[patch 1/2] x86/kvm: Handle async page faults directly through do_page_fault()")
url: https://github.com/0day-ci/linux/commits/Thomas-Gleixner/x86-kvm-Sanitize-async-page-fault/20200307-081908


in testcase: trinity
with following parameters:

	runtime: 300s

test-description: Trinity is a linux system call fuzz tester.
test-url: http://codemonkey.org.uk/projects/trinity/


on test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 8G

caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace):


+--------------------------------------------------+------------+------------+
|                                                  | 6f2bc932d8 | aec3011ae9 |
+--------------------------------------------------+------------+------------+
| boot_successes                                   | 4          | 0          |
| boot_failures                                    | 0          | 4          |
| WARNING:at_arch/x86/kernel/kvm.c:#kvm_guest_init | 0          | 4          |
| EIP:kvm_guest_init                               | 0          | 4          |
+--------------------------------------------------+------------+------------+


If you fix the issue, kindly add following tag
Reported-by: kernel test robot <rong.a.chen@intel.com>


[    0.125854] WARNING: CPU: 0 PID: 0 at arch/x86/kernel/kvm.c:315 kvm_guest_init+0x16a/0x320
[    0.127431] Modules linked in:
[    0.127952] CPU: 0 PID: 0 Comm: swapper Not tainted 5.6.0-rc4-00302-gaec3011ae9800 #1
[    0.129268] EIP: kvm_guest_init+0x16a/0x320
[    0.129963] Code: 3d 48 01 e3 c1 00 75 08 81 eb 78 70 64 30 eb 7a a1 60 2f ff c1 c1 cb 09 85 c0 7e 08 81 f3 3a db 99 8c eb 08 81 c3 3b 07 f9 38 <0f> 0b b8 00 01 e3 c1 c1 c3 05 e8 5e 53 0d ff 89 c6 89 c7 b8 0a 00
[    0.133095] EAX: 00000000 EBX: cc9cbde8 ECX: 00000004 EDX: 00000000
[    0.134152] ESI: c1ff5380 EDI: c1ff5380 EBP: c1e0df24 ESP: 2eb9a4ae
[    0.135197] DS: 007b ES: 007b FS: 0000 GS: 00e0 SS: 0c00 EFLAGS: 00210096
[    0.136332] CR0: 80050033 CR2: 00000000 CR3: 01fe5000 CR4: 00040690
[    0.137358] Call Trace:
[    0.137771] irq event stamp: 0
[    0.138297] hardirqs last  enabled at (0): [<00000000>] 0x0
[    0.139227] hardirqs last disabled at (0): [<00000000>] 0x0
[    0.140175] softirqs last  enabled at (0): [<00000000>] 0x0
[    0.141084] softirqs last disabled at (0): [<00000000>] 0x0
[    0.142057] random: get_random_bytes called from init_oops_id+0x20/0x36 with crng_init=0
[    0.142078] ---[ end trace 0000000000000000 ]---


To reproduce:

        # build kernel
	cd linux
	cp config-5.6.0-rc4-00302-gaec3011ae9800 .config
	make HOSTCC=gcc-7 CC=gcc-7 ARCH=i386 olddefconfig prepare modules_prepare bzImage

        git clone https://github.com/intel/lkp-tests.git
        cd lkp-tests
        bin/lkp qemu -k <bzImage> job-script # job-script is attached in this email



Thanks,
Rong Chen