x86/irqflags: Provide native versions of the local_irq_save()/restore()

Functions that need to disable IRQs, but are common to both early boot and
post-boot execution, are unable to deal with paravirt support associated
with local_irq_save() and local_irq_restore().

Create native versions of these for use in these situations.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/c4c33c0d07200164a3dd8cfd6da0344f57732648.1717600736.git.thomas.lendacky@amd.com

diff --git a/arch/x86/include/asm/irqflags.h b/arch/x86/include/asm/irqflags.h
index 8c5ae649d2df82999815998c5ba92ba044dfbea9..cf7fc2b8e3ce1f4e5f5703ae9fbb5a7e1182ad4f 100644 (file)
--- a/arch/x86/include/asm/irqflags.h
+++ b/arch/x86/include/asm/irqflags.h
@@ -54,6 +54,26 @@ static __always_inline void native_halt(void)
        asm volatile("hlt": : :"memory");
 }
 
+static __always_inline int native_irqs_disabled_flags(unsigned long flags)
+{
+       return !(flags & X86_EFLAGS_IF);
+}
+
+static __always_inline unsigned long native_local_irq_save(void)
+{
+       unsigned long flags = native_save_fl();
+
+       native_irq_disable();
+
+       return flags;
+}
+
+static __always_inline void native_local_irq_restore(unsigned long flags)
+{
+       if (!native_irqs_disabled_flags(flags))
+               native_irq_enable();
+}
+
 #endif
 
 #ifdef CONFIG_PARAVIRT_XXL