From: Bruno Alvisio <bruno.alvisio@gmail.com>
Date: Thu, 14 Dec 2017 00:30:10 +0000 (-0800)
Subject: Save/Restore Support: Refactor trap_init() and setup vector callbacks
X-Git-Tag: xen-RELEASE-4.14.0~24
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=29a343da9f9ec0723b74015234869a00df18db27;p=mini-os.git

Save/Restore Support: Refactor trap_init() and setup vector callbacks

Currently the setup of the IDT and the request to set the HVM vector callbacks
are performed both in the trap_init function.

As part of the post-suspend operation, the HVM vector callback needs to be setup
again while the IDT does not. Thus, the trap_init function is split into two
separate functions: trap_init (sets up IDT) and xen_callback_vector (sets the
HVM vector callback). During the post-suspend operations the xen_callback_vector
function will be invoked.

Signed-off-by: Bruno Alvisio <bruno.alvisio@gmail.com>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
---

diff --git a/arch/x86/traps.c b/arch/x86/traps.c
index aa17da3..a7388a5 100644
--- a/arch/x86/traps.c
+++ b/arch/x86/traps.c
@@ -389,6 +389,16 @@ static void setup_gate(unsigned int entry, void *addr, unsigned int dpl)
 #endif
 }
 
+void xen_callback_vector(void)
+{
+    if (hvm_set_parameter(HVM_PARAM_CALLBACK_IRQ,
+                         (2ULL << 56) | TRAP_xen_callback))
+    {
+        xprintk("Request for Xen HVM callback vector failed\n");
+        do_exit();
+    }
+}
+
 void trap_init(void)
 {
     setup_gate(TRAP_divide_error, &divide_error, 0);
@@ -415,12 +425,7 @@ void trap_init(void)
     gdt[GDTE_TSS] = (typeof(*gdt))INIT_GDTE((unsigned long)&tss, 0x67, 0x89);
     asm volatile ("ltr %w0" :: "rm" (GDTE_TSS * 8));
 
-    if ( hvm_set_parameter(HVM_PARAM_CALLBACK_IRQ,
-                           (2ULL << 56) | TRAP_xen_callback) )
-    {
-        xprintk("Request for Xen HVM callback vector failed\n");
-        do_exit();
-    }
+    xen_callback_vector();
 }
 
 void trap_fini(void)
diff --git a/include/x86/os.h b/include/x86/os.h
index fbc2eeb..d155914 100644
--- a/include/x86/os.h
+++ b/include/x86/os.h
@@ -67,6 +67,9 @@ extern shared_info_t *HYPERVISOR_shared_info;
 
 void trap_init(void);
 void trap_fini(void);
+#ifndef CONFIG_PARAVIRT
+void xen_callback_vector(void);
+#endif
 
 void arch_fini(void);