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

From: tip-bot2 for Thomas Gleixner
Date: Tue May 19 2020 - 15:58:39 EST


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__ */

/*