From: Andi Kleen ak@linux.intel.com
[ Upstream commit 8c16dc047b5dd8f7b3bf4584fa75733ea0dde7dc ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/events/intel/lbr.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/arch/x86/events/intel/lbr.c b/arch/x86/events/intel/lbr.c index 9e6d6eaeb4cb6..f455dd93f9219 100644 --- a/arch/x86/events/intel/lbr.c +++ b/arch/x86/events/intel/lbr.c @@ -1734,6 +1734,9 @@ 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;