diff mbox series

[RFC,05/32] x86/traps: add exc_raise_irq() for VMX IRQ reinjection

Message ID 20221220063658.19271-6-xin3.li@intel.com
State New
Headers
Series x86: enable FRED for x86-64 |

Commit Message

Li, Xin3 Dec. 20, 2022, 6:36 a.m. UTC 
  To eliminate dispatching IRQ through the IDT, add exc_raise_irq(),
which calls external_interrupt() for IRQ reinjection.

Signed-off-by: Xin Li <xin3.li@intel.com>
---
 arch/x86/include/asm/traps.h |  2 ++
 arch/x86/kernel/traps.c      | 18 ++++++++++++++++++
 2 files changed, 20 insertions(+)

Comments

Li, Xin3 Jan. 9, 2023, 6:20 p.m. UTC | #1 
> diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h
> index 46f5e4e2a346..366b1675c033 100644
> --- a/arch/x86/include/asm/traps.h
> +++ b/arch/x86/include/asm/traps.h
> @@ -56,4 +56,6 @@ void __noreturn handle_stack_overflow(struct pt_regs
> *regs,
>  	void f (struct pt_regs *regs)
>  typedef DECLARE_SYSTEM_INTERRUPT_HANDLER((*system_interrupt_handler));
> 
> +int exc_raise_irq(struct pt_regs *regs, u32 vector);
> +
>  #endif /* _ASM_X86_TRAPS_H */
> diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
> index c35dd2b4d146..99386836b02e 100644
> --- a/arch/x86/kernel/traps.c
> +++ b/arch/x86/kernel/traps.c
> @@ -1536,6 +1536,24 @@ int external_interrupt(struct pt_regs *regs, unsigned
> int vector)
>  	return 0;
>  }
> 
> +#if IS_ENABLED(CONFIG_KVM_INTEL)
> +/*
> + * KVM VMX reinjects IRQ on its current stack, it's a sync call
> + * thus the values in the pt_regs structure are not used in
> + * executing IRQ handlers, except cs.RPL and flags.IF, which
> + * are both always 0 in the VMX IRQ reinjection context.
> + *
> + * However, the pt_regs structure is sometimes used in stack
> + * dump, e.g., show_regs(). So let the caller, i.e., KVM VMX
> + * decide how to initialize the input pt_regs structure.
> + */
> +int exc_raise_irq(struct pt_regs *regs, u32 vector)
> +{
> +	return external_interrupt(regs, vector);
> +}
> +EXPORT_SYMBOL_GPL(exc_raise_irq);
> +#endif

Maybe it's better to simply export external_interrupt()

 +EXPORT_SYMBOL_GPL(external_interrupt);

Then I don't need to add exc_raise_irq().

> +
>  void __init trap_init(void)
>  {
>  	/* Init cpu_entry_area before IST entries are set up */
> --
> 2.34.1
diff mbox series

Patch

diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h
index 46f5e4e2a346..366b1675c033 100644
--- a/arch/x86/include/asm/traps.h
+++ b/arch/x86/include/asm/traps.h
@@ -56,4 +56,6 @@  void __noreturn handle_stack_overflow(struct pt_regs *regs,
 	void f (struct pt_regs *regs)
 typedef DECLARE_SYSTEM_INTERRUPT_HANDLER((*system_interrupt_handler));
 
+int exc_raise_irq(struct pt_regs *regs, u32 vector);
+
 #endif /* _ASM_X86_TRAPS_H */
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index c35dd2b4d146..99386836b02e 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -1536,6 +1536,24 @@  int external_interrupt(struct pt_regs *regs, unsigned int vector)
 	return 0;
 }
 
+#if IS_ENABLED(CONFIG_KVM_INTEL)
+/*
+ * KVM VMX reinjects IRQ on its current stack, it's a sync call
+ * thus the values in the pt_regs structure are not used in
+ * executing IRQ handlers, except cs.RPL and flags.IF, which
+ * are both always 0 in the VMX IRQ reinjection context.
+ *
+ * However, the pt_regs structure is sometimes used in stack
+ * dump, e.g., show_regs(). So let the caller, i.e., KVM VMX
+ * decide how to initialize the input pt_regs structure.
+ */
+int exc_raise_irq(struct pt_regs *regs, u32 vector)
+{
+	return external_interrupt(regs, vector);
+}
+EXPORT_SYMBOL_GPL(exc_raise_irq);
+#endif
+
 void __init trap_init(void)
 {
 	/* Init cpu_entry_area before IST entries are set up */