[PATCH 06/10] x86/fpu: Log XSAVE disablement consistently

From: Chang S. Bae
Date: Tue Apr 15 2025 - 22:18:52 EST


Not all paths that lead to fpu__init_disable_system_xstate() currently
emit a message indicating that XSAVE has been disabled. Move the print
statement into the function to ensure the message in all cases.

Suggested-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Signed-off-by: Chang S. Bae <chang.seok.bae@xxxxxxxxx>
Link: https://lore.kernel.org/lkml/d6d19e39-2749-4d45-aeab-a209a0ecba17@xxxxxxxxx
---
New patch for following up patch 3.
---
arch/x86/kernel/fpu/xstate.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index 2ac1fc182273..8b14c9d3a1df 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -751,6 +751,8 @@ static int __init init_xstate_size(void)
*/
static void __init fpu__init_disable_system_xstate(unsigned int legacy_size)
{
+ pr_info("x86/fpu: XSAVE disabled\n");
+
fpu_kernel_cfg.max_features = 0;
cr4_clear_bits(X86_CR4_OSXSAVE);
setup_clear_cpu_cap(X86_FEATURE_XSAVE);
@@ -821,7 +823,7 @@ void __init fpu__init_system_xstate(unsigned int legacy_size)
* This is a problematic CPU configuration where two
* conflicting state components are both enumerated.
*/
- pr_err("x86/fpu: Both APX/MPX present in the CPU's xstate features: 0x%llx, disabling XSAVE.\n",
+ pr_err("x86/fpu: Both APX/MPX present in the CPU's xstate features: 0x%llx.\n",
fpu_kernel_cfg.max_features);
goto out_disable;
}
@@ -900,7 +902,7 @@ void __init fpu__init_system_xstate(unsigned int legacy_size)
init_fpstate.xfeatures = fpu_kernel_cfg.default_features;

if (init_fpstate.size > sizeof(init_fpstate.regs)) {
- pr_warn("x86/fpu: init_fpstate buffer too small (%zu < %d), disabling XSAVE\n",
+ pr_warn("x86/fpu: init_fpstate buffer too small (%zu < %d)\n",
sizeof(init_fpstate.regs), init_fpstate.size);
goto out_disable;
}
@@ -912,7 +914,7 @@ void __init fpu__init_system_xstate(unsigned int legacy_size)
* xfeatures mask.
*/
if (xfeatures != fpu_kernel_cfg.max_features) {
- pr_err("x86/fpu: xfeatures modified from 0x%016llx to 0x%016llx during init, disabling XSAVE\n",
+ pr_err("x86/fpu: xfeatures modified from 0x%016llx to 0x%016llx during init\n",
xfeatures, fpu_kernel_cfg.max_features);
goto out_disable;
}
--
2.45.2