On 03.12.2021 12:48, Andrew Cooper wrote:
> On 03/12/2021 11:21, Jan Beulich wrote:
>> The SDM explicitly permits this, and since that's sensible behavior
>> don't special case AMD (where the PM doesn't explicitly say so).
>
> APM explicitly says so too.
>
> "The CLFLUSH instruction executes at any privilege level. CLFLUSH
> performs all the segmentation and paging checks that a 1-byte read would
> perform, except that it also allows references to execute-only segments."
>
> and
>
> "The CLFLUSHOPT instruction executes at any privilege level. CLFLUSHOPT
> performs all the segmentation and paging checks that a 1-byte read would
> perform, except that it also allows references to execute-only segments."
Somehow I didn't read further after the page table related paragraph,
perhaps on the assumption that like in the SDM it would be all in one
paragraph.
>> Fixes: 52dba7bd0b36 ("x86emul: generalize wbinvd() hook")
>> Reported-by: Andrew Cooper <[email protected]>
>> Signed-off-by: Jan Beulich <[email protected]>
>
> With the commit message tweaked, Reviewed-by: Andrew Cooper
> <[email protected]>. Far less invasive than I was fearing.
Thanks. I've switched to simply saying "Both SDM and PM explicitly
permit this."
Jan
