[PATCH 3/3] x86/trampoline: Collect other scattered trampoline symbols

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

... and document them too.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
CC: Jan Beulich <JBeulich@xxxxxxxx>
CC: Roger Pau Monné <roger.pau@xxxxxxxxxx>
CC: Frediano Ziglio <frediano.ziglio@xxxxxxxxx>
CC: Alejandro Vallejo <alejandro.vallejo@xxxxxxxxx>

video.h, edd.h and e820.h also contain trampoline symbols, but they're pretty
well contained headers already.

kbd_shift_flags seems especially dubious.  It's a snapshot of the keyboard
state when Xen happened to pass through the trampoline, and surely cannot be
useful for dom0 in the slightest...
---
 xen/arch/x86/efi/efi-boot.h           |  3 ---
 xen/arch/x86/include/asm/processor.h  |  2 --
 xen/arch/x86/include/asm/setup.h      |  2 --
 xen/arch/x86/include/asm/trampoline.h | 22 ++++++++++++++++++++++
 4 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/xen/arch/x86/efi/efi-boot.h b/xen/arch/x86/efi/efi-boot.h
index 23e510c77e2e..833e343a475e 100644
--- a/xen/arch/x86/efi/efi-boot.h
+++ b/xen/arch/x86/efi/efi-boot.h
@@ -102,9 +102,6 @@ static void __init efi_arch_relocate_image(unsigned long 
delta)
     }
 }
 
-extern const s32 __trampoline_rel_start[], __trampoline_rel_stop[];
-extern const s32 __trampoline_seg_start[], __trampoline_seg_stop[];
-
 static void __init relocate_trampoline(unsigned long phys)
 {
     const s32 *trampoline_ptr;
diff --git a/xen/arch/x86/include/asm/processor.h 
b/xen/arch/x86/include/asm/processor.h
index e71dbb8d3fbf..b8d8127e2dc3 100644
--- a/xen/arch/x86/include/asm/processor.h
+++ b/xen/arch/x86/include/asm/processor.h
@@ -97,8 +97,6 @@ extern void ctxt_switch_levelling(const struct vcpu *next);
 extern void (*ctxt_switch_masking)(const struct vcpu *next);
 
 extern bool opt_cpu_info;
-extern u32 trampoline_efer;
-extern u64 trampoline_misc_enable_off;
 
 /* Maximum width of physical addresses supported by the hardware. */
 extern unsigned int paddr_bits;
diff --git a/xen/arch/x86/include/asm/setup.h b/xen/arch/x86/include/asm/setup.h
index d75589178b91..4d88503fd2e6 100644
--- a/xen/arch/x86/include/asm/setup.h
+++ b/xen/arch/x86/include/asm/setup.h
@@ -40,8 +40,6 @@ int remove_xen_ranges(struct rangeset *r);
 
 int cf_check stub_selftest(void);
 
-extern uint8_t kbd_shift_flags;
-
 #ifdef NDEBUG
 # define highmem_start 0
 #else
diff --git a/xen/arch/x86/include/asm/trampoline.h 
b/xen/arch/x86/include/asm/trampoline.h
index cc3420ba3530..dc2c47946be4 100644
--- a/xen/arch/x86/include/asm/trampoline.h
+++ b/xen/arch/x86/include/asm/trampoline.h
@@ -49,6 +49,13 @@
 /* SAF-0-safe */
 extern char trampoline_start[], trampoline_end[];
 
+/*
+ * Relocations for the trampoline.  Generated by the bootsym_{seg,}rel()
+ * macros, and collected by the linker.
+ */
+extern const int32_t __trampoline_rel_start[], __trampoline_rel_stop[];
+extern const int32_t __trampoline_seg_start[], __trampoline_seg_stop[];
+
 /*
  * The physical address of trampoline_start[] in low memory.  It must be below
  * the 1M boundary (as the trampoline contains 16-bit code), and must be 4k
@@ -87,9 +94,24 @@ extern uint32_t trampoline_xen_phys_start;
 /* A semaphore to indicate signs-of-life at the start of the AP boot path. */
 extern uint8_t trampoline_cpu_started;
 
+/*
+ * Extra MSR_EFER settings when activating Long Mode.  EFER_NXE is necessary
+ * for APs to boot if the BSP found and activated support.
+ */
+extern uint32_t trampoline_efer;
+
+/*
+ * When nonzero, clear the specified bits in MSR_MISC_ENABLE.  This is
+ * necessary to clobber XD_DISABLE before trying to set MSR_EFER.NXE.
+ */
+extern uint64_t trampoline_misc_enable_off;
+
 /* Quirks about video mode-setting on S3 resume. */
 extern uint8_t video_flags;
 
+/* BIOS Int 16h, Fn 02h.  The keyboard shift status. */
+extern uint8_t kbd_shift_flags;
+
 /* Extended Display Identification Data, gathered from the BIOS. */
 extern uint16_t boot_edid_caps;
 extern uint8_t boot_edid_info[128];
-- 
2.39.2