x86 Fix VMI crash on boot in 2.6.28-rc8

commit ae8d04e2ecbb233926860e9ce145eac19c7835dc upstream.

VMI initialiation can relocate the fixmap, causing early_ioremap to
malfunction if it is initialized before the relocation.  To fix this,
VMI activation is split into two phases; the detection, which must
happen before setting up ioremap, and the activation, which must happen
after parsing early boot parameters.

This fixes a crash on boot when VMI is enabled under VMware.

Signed-off-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

3 files changed, 16 insertions, 14 deletions

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 7667443aa4a8..6d5a3c43968a 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -634,6 +634,9 @@ void __init setup_arch(char **cmdline_p)
 	printk(KERN_INFO "Command line: %s\n", boot_command_line);
 #endif
 
+	/* VMI may relocate the fixmap; do this before touching ioremap area */
+	vmi_init();
+
 	early_cpu_init();
 	early_ioremap_init();
 
@@ -707,13 +710,8 @@ void __init setup_arch(char **cmdline_p)
 	check_efer();
 #endif
 
-#if defined(CONFIG_VMI) && defined(CONFIG_X86_32)
-	/*
-	 * Must be before kernel pagetables are setup
-	 * or fixmap area is touched.
-	 */
-	vmi_init();
-#endif
+	/* Must be before kernel pagetables are setup */
+	vmi_activate();
 
 	/* after early param, so could get panic from serial */
 	reserve_early_setup_data();
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 7985c5b3f916..259569ff0b0c 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -289,9 +289,7 @@ static void __cpuinit start_secondary(void *unused)
 	 * fragile that we want to limit the things done here to the
 	 * most necessary things.
 	 */
-#ifdef CONFIG_VMI
 	vmi_bringup();
-#endif
 	cpu_init();
 	preempt_disable();
 	smp_callin();
diff --git a/arch/x86/kernel/vmi_32.c b/arch/x86/kernel/vmi_32.c
index edfb09f30479..f370d38ec8d0 100644
--- a/arch/x86/kernel/vmi_32.c
+++ b/arch/x86/kernel/vmi_32.c
@@ -960,8 +960,6 @@ static inline int __init activate_vmi(void)
 
 void __init vmi_init(void)
 {
-	unsigned long flags;
-
 	if (!vmi_rom)
 		probe_vmi_rom();
 	else
@@ -973,13 +971,21 @@ void __init vmi_init(void)
 
 	reserve_top_address(-vmi_rom->virtual_top);
 
-	local_irq_save(flags);
-	activate_vmi();
-
 #ifdef CONFIG_X86_IO_APIC
 	/* This is virtual hardware; timer routing is wired correctly */
 	no_timer_check = 1;
 #endif
+}
+
+void vmi_activate(void)
+{
+	unsigned long flags;
+
+	if (!vmi_rom)
+		return;
+
+	local_irq_save(flags);
+	activate_vmi();
 	local_irq_restore(flags & X86_EFLAGS_IF);
 }