[tip: x86/entry] x86/idtentry: Provide IDTENTRY_XEN for XEN/PV

[tip-bot2 for Thomas Gleixner]

The following commit has been merged into the x86/entry branch of tip:

Commit-ID:     9769a24d77c5708376bf99e04cffe5c764cd3e40
Gitweb:        https://git.kernel.org/tip/9769a24d77c5708376bf99e04cffe5c764cd3e40
Author:        Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate:    Tue, 25 Feb 2020 23:33:24 +01:00
Committer:     Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Tue, 19 May 2020 16:04:09 +02:00

x86/idtentry: Provide IDTENTRY_XEN for XEN/PV

XEN/PV has special wrappers for NMI and DB exceptions. They redirect these
exceptions through regular IDTENTRY points. Provide the necessary IDTENTRY
macros to make this work

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Alexandre Chartre <alexandre.chartre@xxxxxxxxxx>
Acked-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Acked-by: Andy Lutomirski <luto@xxxxxxxxxx>
Link: https://lkml.kernel.org/r/20200505135314.518622698@xxxxxxxxxxxxx


---
 arch/x86/include/asm/idtentry.h | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h
index 36fe964..2315eec 100644
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -168,6 +168,18 @@ __visible noinstr void func(struct pt_regs *regs)
 #define DECLARE_IDTENTRY_DEBUG		DECLARE_IDTENTRY_IST
 #define DEFINE_IDTENTRY_DEBUG		DEFINE_IDTENTRY_IST
 
+/**
+ * DECLARE_IDTENTRY_XEN - Declare functions for XEN redirect IDT entry points
+ * @vector:	Vector number (ignored for C)
+ * @func:	Function name of the entry point
+ *
+ * Used for xennmi and xendebug redirections. No DEFINE as this is all ASM
+ * indirection magic.
+ */
+#define DECLARE_IDTENTRY_XEN(vector, func)				\
+	asmlinkage void xen_asm_exc_xen##func(void);			\
+	asmlinkage void asm_exc_xen##func(void)
+
 #else /* !__ASSEMBLY__ */
 
 /*
@@ -203,6 +215,10 @@ __visible noinstr void func(struct pt_regs *regs)
 /* No ASM code emitted for NMI */
 #define DECLARE_IDTENTRY_NMI(vector, func)
 
+/* XEN NMI and DB wrapper */
+#define DECLARE_IDTENTRY_XEN(vector, func)				\
+	idtentry vector asm_exc_xen##func exc_##func has_error_code=0 sane=1
+
 #endif /* __ASSEMBLY__ */
 
 /*