On 24.10.2019 05:45, Marek Marczykowski-Górecki wrote:
> Some UEFI implementations are not happy about lack of
> SetVirtualAddressMap() call. Likely abuse the address map change
> notification to do things beyond the necessary ConvertPointer() calls.
> Specifically, wihtout the SetVirtualAddressMap() call, some access
> EfiBootServices{Code,Data}, or even totally unmapped areas. Example
> crash of GetVariable() call on Thinkpad W540:
>
> Xen call trace:
> [<0000000000000080>] 0000000000000080
> [<8c2b0398e0000daa>] 8c2b0398e0000daa
>
> Pagetable walk from ffffffff858483a1:
> L4[0x1ff] = 0000000000000000 ffffffffffffffff
>
> ****************************************
> Panic on CPU 0:
> FATAL PAGE FAULT
> [error_code=0002]
> Faulting linear address: ffffffff858483a1
> ****************************************
>
> Fix this by calling SetVirtualAddressMap() runtime service, giving it
> 1:1 map for areas marked as needed during runtime. The address space in
> which EFI runtime services are called is unchanged, but UEFI view of it
> may be.
> Since it's fairly late in Xen 4.13 development cycle, disable it
> by default and hide behind EXPERT.
>
> Signed-off-by: Marek Marczykowski-Górecki <marma...@invisiblethingslab.com>
Reviewed-by: Jan Beulich <jbeul...@suse.com>
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
