[PATCH] x86,spinlock: make disabling virt_spin_lock_key contingent on CONFIG_PARAVIRT

From: Rik van Riel
Date: Mon Jul 15 2024 - 13:19:27 EST


The existence of virt_spin_lock_key is contingent only on CONFIG_PARAVIRT, not
on CONFIG_PARAVIRT_SPINLOCKS.

As a result, a kernel with CONFIG_PARAVIRT enabled, but CONFIG_PARAVIRT_SPINLOCKS
disabled will end up disabling queued spinlocks when running on bare metal.

Making the disabling of virt_spin_lock_key contingent on CONFIG_PARAVIRT, which
controls whether the key exists, results in queued spinlocks being enabled on
bare metal again.

Signed-off-by: Rik van Riel <riel@xxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Fixes: ce0a1b608bfc ("x86/paravirt: Silence unused native_pv_lock_init() function warning")
---
arch/x86/kernel/paravirt.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
index 5358d43886ad..dd542a9c6667 100644
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -55,7 +55,7 @@ DEFINE_STATIC_KEY_TRUE(virt_spin_lock_key);

void __init native_pv_lock_init(void)
{
- if (IS_ENABLED(CONFIG_PARAVIRT_SPINLOCKS) &&
+ if (IS_ENABLED(CONFIG_PARAVIRT) &&
!boot_cpu_has(X86_FEATURE_HYPERVISOR))
static_branch_disable(&virt_spin_lock_key);
}
--
2.45.2