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.
kvm: emulating exchange as write
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BUG: KCSAN: data-race in direct_page_fault / kvm_mmu_notifier_invalidate_range_end

write to 0xffffc9000403a188 of 8 bytes by task 14619 on cpu 0:
 kvm_mmu_notifier_invalidate_range_end+0x39/0xa0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:453
 mn_hlist_invalidate_end mm/mmu_notifier.c:560 [inline]
 __mmu_notifier_invalidate_range_end+0x18e/0x210 mm/mmu_notifier.c:580
 mmu_notifier_invalidate_range_only_end include/linux/mmu_notifier.h:480 [inline]
 wp_page_copy+0x9ac/0x1620 mm/memory.c:2763
 do_wp_page+0x9c3/0xd40 mm/memory.c:2981
 handle_pte_fault mm/memory.c:4232 [inline]
 __handle_mm_fault mm/memory.c:4346 [inline]
 handle_mm_fault+0x1658/0x18a0 mm/memory.c:4383
 do_user_addr_fault+0x393/0x810 arch/x86/mm/fault.c:1295
 handle_page_fault arch/x86/mm/fault.c:1365 [inline]
 exc_page_fault+0xb8/0x330 arch/x86/mm/fault.c:1418
 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:565

read to 0xffffc9000403a188 of 8 bytes by task 14623 on cpu 1:
 direct_page_fault+0x162/0x670 arch/x86/kvm/mmu/mmu.c:4121
 kvm_tdp_page_fault+0x92/0xa0 arch/x86/kvm/mmu/mmu.c:4208
 kvm_mmu_do_page_fault arch/x86/kvm/mmu.h:115 [inline]
 kvm_mmu_page_fault+0xca/0x410 arch/x86/kvm/mmu/mmu.c:5422
 handle_ept_violation+0x232/0x5c0 arch/x86/kvm/vmx/vmx.c:5314
 vmx_handle_exit+0x554/0xb40 arch/x86/kvm/vmx/vmx.c:6093
 vcpu_enter_guest+0x189c/0x23e0 arch/x86/kvm/x86.c:8593
 vcpu_run+0x26e/0x750 arch/x86/kvm/x86.c:8658
 kvm_arch_vcpu_ioctl_run+0x38d/0x690 arch/x86/kvm/x86.c:8879
 kvm_vcpu_ioctl+0x565/0x950 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3166
 vfs_ioctl fs/ioctl.c:48 [inline]
 ksys_ioctl fs/ioctl.c:753 [inline]
 __do_sys_ioctl fs/ioctl.c:762 [inline]
 __se_sys_ioctl+0xc9/0x130 fs/ioctl.c:760
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:760
 do_syscall_64+0x71/0x120 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 14623 Comm: syz-executor.5 Not tainted 5.8.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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