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: 5904 at arch/x86/kvm/vmx/vmx.c:4804 handle_rmode_exception arch/x86/kvm/vmx/vmx.c:4702 [inline]
WARNING: CPU: 0 PID: 5904 at arch/x86/kvm/vmx/vmx.c:4804 handle_exception_nmi+0xd80/0x1040 arch/x86/kvm/vmx/vmx.c:4814
Modules linked in:
CPU: 1 PID: 5904 Comm: syz-executor.0 Not tainted 5.11.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:handle_exception_nmi+0xd80/0x1040 arch/x86/kvm/vmx/vmx.c:4804
Code: 00 00 85 d2 0f 84 db f4 ff ff c7 85 b4 0e 00 00 00 00 00 00 48 83 c4 18 48 89 ef 5b 5d 41 5c 41 5d 41 5e 41 5f e9 c0 c0 f1 ff <0f> 0b e9 7e f9 ff ff 4c 89 f7 e8 41 7d 87 00 e9 0d f3 ff ff 4c 89
RSP: 0018:ffffc90001ab7bb0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000080000b0e RCX: 0000000000000000
RDX: 0000000000000000 RSI: 1ffffffff18645b5 RDI: ffff88801d75231c
RBP: ffff88801d750000 R08: 0000000000000001 R09: ffff88801d750347
R10: ffffed1003aea068 R11: ffffffd72ee28176 R12: 00000000a0000975
R13: ffff88801d7500f0 R14: ffff88801d750340 R15: 0000000000000000
FS:  00007f1797f3e700(0000) GS:ffff8880b9e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000a0000975 CR3: 000000001a266000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 vcpu_enter_guest+0x102c/0x3480 arch/x86/kvm/x86.c:9089
 vcpu_run arch/x86/kvm/x86.c:9155 [inline]
 kvm_arch_vcpu_ioctl_run+0x350/0x14b0 arch/x86/kvm/x86.c:9382
 kvm_vcpu_ioctl+0x36f/0xa30 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3283
 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+0x11f/0x190 fs/ioctl.c:739
 do_syscall_64+0x2d/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f17987c9109
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f1797f3e168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f17988dbf60 RCX: 00007f17987c9109
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005
RBP: 00007f17988230ad R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffe0a87c81f R14: 00007f1797f3e300 R15: 0000000000022000