mirror of
https://github.com/torvalds/linux.git
synced 2024-12-22 10:56:40 +00:00
c08800a56c
SMEP is disabled if CPU is in non-paging mode in hardware. However KVM always uses paging mode to emulate guest non-paging mode with TDP. To emulate this behavior, SMEP needs to be manually disabled when guest switches to non-paging mode. We met an issue that, SMP Linux guest with recent kernel (enable SMEP support, for example, 3.5.3) would crash with triple fault if setting unrestricted_guest=0. This is because KVM uses an identity mapping page table to emulate the non-paging mode, where the page table is set with USER flag. If SMEP is still enabled in this case, guest will meet unhandlable page fault and then crash. Reviewed-by: Gleb Natapov <gleb@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Dongxiao Xu <dongxiao.xu@intel.com> Signed-off-by: Xiantao Zhang <xiantao.zhang@intel.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> |
||
|---|---|---|
| .. | ||
| boot | ||
| configs | ||
| crypto | ||
| ia32 | ||
| include | ||
| kernel | ||
| kvm | ||
| lguest | ||
| lib | ||
| math-emu | ||
| mm | ||
| net | ||
| oprofile | ||
| pci | ||
| platform | ||
| power | ||
| realmode | ||
| syscalls | ||
| tools | ||
| um | ||
| vdso | ||
| video | ||
| xen | ||
| .gitignore | ||
| Kbuild | ||
| Kconfig | ||
| Kconfig.cpu | ||
| Kconfig.debug | ||
| Makefile | ||
| Makefile_32.cpu | ||
| Makefile.um | ||