[PATCH 10/15] kdump: Hook emergency_virt_disable() on crash shutdown code

Eduardo Habkost
2008-11-05T19:56:53Z

[v2: add comments on source code, explaining why it is needed]

Signed-off-by: Eduardo Habkost <ehabkost-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
---
arch/x86/kernel/crash.c | 13 +++++++++++++
1 files changed, 13 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
index d84a852..040f3ca 100644
--- a/arch/x86/kernel/crash.c
+++ b/arch/x86/kernel/crash.c
@@ -26,6 +26,7 @@
#include <linux/kdebug.h>
#include <asm/smp.h>
#include <asm/reboot.h>
+#include <asm/virtext.h>

#include <mach_ipi.h>

@@ -49,6 +50,11 @@ static void kdump_nmi_callback(int cpu, struct die_args *args)
#endif
crash_save_cpu(regs, cpu);

+ /* We need to disable virtualization on all CPUs.
+ * Having VMX or SVM enabled on any CPU may break rebooting
+ * after the kdump kernel has finished its task.
+ */
+ emergency_virt_disable();
disable_local_APIC();
}

@@ -80,6 +86,13 @@ void native_machine_crash_shutdown(struct pt_regs *regs)
local_irq_disable();

kdump_nmi_shootdown_cpus();
+
+ /* Booting kdump kernel with VMX or SVM enabled won't work,
+ * because (among other limitations) we can't disable paging
+ * with the virt flags.
+ */
+ emergency_virt_disable();
+
lapic_shutdown();
#if defined(CONFIG_X86_IO_APIC)
disable_IO_APIC();
--
1.5.5.GIT