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authorZhang Yanfei <zhangyanfei@cn.fujitsu.com>2012-12-06 23:40:47 +0800
committerGleb Natapov <gleb@redhat.com>2012-12-06 18:25:36 +0200
commitf23d1f4a116038c68df224deae6718fde87d8f0d (patch)
tree72d414b6fddf5b726559fba66d2f1d7ffc21de7b /arch/x86
parentc21934632549910188fb5cf40e79033f27a0741b (diff)
downloadlinux-f23d1f4a116038c68df224deae6718fde87d8f0d.tar.bz2
x86/kexec: VMCLEAR VMCSs loaded on all cpus if necessary
This patch provides a way to VMCLEAR VMCSs related to guests on all cpus before executing the VMXOFF when doing kdump. This is used to ensure the VMCSs in the vmcore updated and non-corrupted. Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Acked-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/include/asm/kexec.h2
-rw-r--r--arch/x86/kernel/crash.c32
2 files changed, 34 insertions, 0 deletions
diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h
index 317ff1703d0b..28feeba2fdd6 100644
--- a/arch/x86/include/asm/kexec.h
+++ b/arch/x86/include/asm/kexec.h
@@ -163,6 +163,8 @@ struct kimage_arch {
};
#endif
+extern void (*crash_vmclear_loaded_vmcss)(void);
+
#endif /* __ASSEMBLY__ */
#endif /* _ASM_X86_KEXEC_H */
diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
index 13ad89971d47..2f6b8e838d18 100644
--- a/arch/x86/kernel/crash.c
+++ b/arch/x86/kernel/crash.c
@@ -16,6 +16,7 @@
#include <linux/delay.h>
#include <linux/elf.h>
#include <linux/elfcore.h>
+#include <linux/module.h>
#include <asm/processor.h>
#include <asm/hardirq.h>
@@ -30,6 +31,27 @@
int in_crash_kexec;
+/*
+ * This is used to VMCLEAR all VMCSs loaded on the
+ * processor. And when loading kvm_intel module, the
+ * callback function pointer will be assigned.
+ *
+ * protected by rcu.
+ */
+void (*crash_vmclear_loaded_vmcss)(void) = NULL;
+EXPORT_SYMBOL_GPL(crash_vmclear_loaded_vmcss);
+
+static inline void cpu_crash_vmclear_loaded_vmcss(void)
+{
+ void (*do_vmclear_operation)(void) = NULL;
+
+ rcu_read_lock();
+ do_vmclear_operation = rcu_dereference(crash_vmclear_loaded_vmcss);
+ if (do_vmclear_operation)
+ do_vmclear_operation();
+ rcu_read_unlock();
+}
+
#if defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC)
static void kdump_nmi_callback(int cpu, struct pt_regs *regs)
@@ -46,6 +68,11 @@ static void kdump_nmi_callback(int cpu, struct pt_regs *regs)
#endif
crash_save_cpu(regs, cpu);
+ /*
+ * VMCLEAR VMCSs loaded on all cpus if needed.
+ */
+ cpu_crash_vmclear_loaded_vmcss();
+
/* Disable VMX or SVM if needed.
*
* We need to disable virtualization on all CPUs.
@@ -88,6 +115,11 @@ void native_machine_crash_shutdown(struct pt_regs *regs)
kdump_nmi_shootdown_cpus();
+ /*
+ * VMCLEAR VMCSs loaded on this cpu if needed.
+ */
+ cpu_crash_vmclear_loaded_vmcss();
+
/* Booting kdump kernel with VMX or SVM enabled won't work,
* because (among other limitations) we can't disable paging
* with the virt flags.