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authorEduardo Habkost <ehabkost@redhat.com>2008-11-17 19:03:23 -0200
committerAvi Kivity <avi@redhat.com>2008-12-31 16:52:30 +0200
commit2340b62f77c782c305e6ae7748675a638436d1ef (patch)
tree07815f82bd09a2ca2c2de17c607a536ae4916454
parent0f3e9eeba0ea212bbea88790729d054b700ab91e (diff)
kdump: forcibly disable VMX and SVM on machine_crash_shutdown()
We need to disable virtualization extensions on all CPUs before booting the kdump kernel, otherwise the kdump kernel booting will fail, and rebooting after the kdump kernel did its task may also fail. We do it using cpu_emergency_vmxoff() and cpu_emergency_svm_disable(), that should always work, because those functions check if the CPUs support SVM or VMX before doing their tasks. Signed-off-by: Eduardo Habkost <ehabkost@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
-rw-r--r--arch/x86/kernel/crash.c18
1 files changed, 18 insertions, 0 deletions
diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
index d84a852e4cd..c689d19e35a 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 +50,15 @@ static void kdump_nmi_callback(int cpu, struct die_args *args)
#endif
crash_save_cpu(regs, cpu);
+ /* Disable VMX or SVM if needed.
+ *
+ * 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.
+ */
+ cpu_emergency_vmxoff();
+ cpu_emergency_svm_disable();
+
disable_local_APIC();
}
@@ -80,6 +90,14 @@ 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.
+ */
+ cpu_emergency_vmxoff();
+ cpu_emergency_svm_disable();
+
lapic_shutdown();
#if defined(CONFIG_X86_IO_APIC)
disable_IO_APIC();