L1TF CPU bug present and SMT on, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/l1tf.html for details.
------------[ cut here ]------------
WARNING: CPU: 0 PID: 6893 at arch/x86/kvm/vmx/vmx.c:4809 handle_exception_nmi+0x10e1/0x12d0 arch/x86/kvm/vmx/vmx.c:4809
Modules linked in:
CPU: 0 PID: 6893 Comm: syz-executor847 Not tainted 5.9.0-rc7-next-20201001-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:handle_exception_nmi+0x10e1/0x12d0 arch/x86/kvm/vmx/vmx.c:4809
Code: 0f 84 16 f3 ff ff e8 1e 4c 59 00 48 89 ef c7 85 ac 0e 00 00 00 00 00 00 e8 6c 9c f0 ff 41 89 c4 e9 fd f2 ff ff e8 ff 4b 59 00 <0f> 0b e9 85 f8 ff ff e8 f3 4b 59 00 be f5 ff ff ff bf 01 00 00 00
RSP: 0018:ffffc90005607b58 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff811bf385
RDX: ffff88808b226080 RSI: ffffffff811bfb01 RDI: 0000000000000001
RBP: ffff8880a8298040 R08: 0000000000000001 R09: ffff8880a8298387
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000002
R13: fffffffffffffff8 R14: ffff8880a8298380 R15: 0000000000000000
FS:  00000000019e1880(0000) GS:ffff8880ae400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc45708f000 CR3: 000000009e938000 CR4: 00000000001526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 vmx_handle_exit+0x2a6/0x1510 arch/x86/kvm/vmx/vmx.c:6123
 vcpu_enter_guest+0x18f4/0x3b20 arch/x86/kvm/x86.c:8655
 vcpu_run arch/x86/kvm/x86.c:8720 [inline]
 kvm_arch_vcpu_ioctl_run+0x440/0x1780 arch/x86/kvm/x86.c:8937
 kvm_vcpu_ioctl+0x467/0xd90 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3230
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl fs/ioctl.c:739 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x443bb9
Code: e8 dc a3 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db 00 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fff938315a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000443bb9
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005
RBP: 00000000006ce018 R08: 0000000000000000 R09: 00000000004002c8
R10: 0000000000000012 R11: 0000000000000246 R12: 0000000000404120
R13: 00000000004041b0 R14: 0000000000000000 R15: 0000000000000000