x86/perf: Avoid warning for Arch LBR without XSAVE

Some hypervisors support Arch LBR, but without the LBR XSAVE support.
The current Arch LBR init code prints a warning when the xsave size (0) is
unexpected. Avoid printing the warning for the "no LBR XSAVE" case.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20211215204029.150686-1-ak@linux.intel.com
This commit is contained in:
Andi Kleen 2021-12-15 12:40:29 -08:00 committed by Peter Zijlstra
parent 5a4487f9ef
commit 8c16dc047b

View File

@ -1751,6 +1751,9 @@ static bool is_arch_lbr_xsave_available(void)
* Check the LBR state with the corresponding software structure.
* Disable LBR XSAVES support if the size doesn't match.
*/
if (xfeature_size(XFEATURE_LBR) == 0)
return false;
if (WARN_ON(xfeature_size(XFEATURE_LBR) != get_lbr_state_size()))
return false;