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Diffstat (limited to 'arch/x86/kernel/kvm.c')
-rw-r--r--arch/x86/kernel/kvm.c129
1 files changed, 83 insertions, 46 deletions
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index d307c22e5c18..a26643dc6bd6 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -26,6 +26,7 @@
#include <linux/kprobes.h>
#include <linux/nmi.h>
#include <linux/swait.h>
+#include <linux/syscore_ops.h>
#include <asm/timer.h>
#include <asm/cpu.h>
#include <asm/traps.h>
@@ -37,6 +38,7 @@
#include <asm/tlb.h>
#include <asm/cpuidle_haltpoll.h>
#include <asm/ptrace.h>
+#include <asm/reboot.h>
#include <asm/svm.h>
DEFINE_STATIC_KEY_FALSE(kvm_async_pf_enabled);
@@ -345,7 +347,7 @@ static void kvm_guest_cpu_init(void)
wrmsrl(MSR_KVM_ASYNC_PF_EN, pa);
__this_cpu_write(apf_reason.enabled, 1);
- pr_info("KVM setup async PF for cpu %d\n", smp_processor_id());
+ pr_info("setup async PF for cpu %d\n", smp_processor_id());
}
if (kvm_para_has_feature(KVM_FEATURE_PV_EOI)) {
@@ -371,34 +373,17 @@ static void kvm_pv_disable_apf(void)
wrmsrl(MSR_KVM_ASYNC_PF_EN, 0);
__this_cpu_write(apf_reason.enabled, 0);
- pr_info("Unregister pv shared memory for cpu %d\n", smp_processor_id());
+ pr_info("disable async PF for cpu %d\n", smp_processor_id());
}
-static void kvm_pv_guest_cpu_reboot(void *unused)
+static void kvm_disable_steal_time(void)
{
- /*
- * We disable PV EOI before we load a new kernel by kexec,
- * since MSR_KVM_PV_EOI_EN stores a pointer into old kernel's memory.
- * New kernel can re-enable when it boots.
- */
- if (kvm_para_has_feature(KVM_FEATURE_PV_EOI))
- wrmsrl(MSR_KVM_PV_EOI_EN, 0);
- kvm_pv_disable_apf();
- kvm_disable_steal_time();
-}
+ if (!has_steal_clock)
+ return;
-static int kvm_pv_reboot_notify(struct notifier_block *nb,
- unsigned long code, void *unused)
-{
- if (code == SYS_RESTART)
- on_each_cpu(kvm_pv_guest_cpu_reboot, NULL, 1);
- return NOTIFY_DONE;
+ wrmsr(MSR_KVM_STEAL_TIME, 0, 0);
}
-static struct notifier_block kvm_pv_reboot_nb = {
- .notifier_call = kvm_pv_reboot_notify,
-};
-
static u64 kvm_steal_clock(int cpu)
{
u64 steal;
@@ -416,14 +401,6 @@ static u64 kvm_steal_clock(int cpu)
return steal;
}
-void kvm_disable_steal_time(void)
-{
- if (!has_steal_clock)
- return;
-
- wrmsr(MSR_KVM_STEAL_TIME, 0, 0);
-}
-
static inline void __set_percpu_decrypted(void *ptr, unsigned long size)
{
early_set_memory_decrypted((unsigned long) ptr, size);
@@ -451,6 +428,27 @@ static void __init sev_map_percpu_data(void)
}
}
+static void kvm_guest_cpu_offline(bool shutdown)
+{
+ kvm_disable_steal_time();
+ if (kvm_para_has_feature(KVM_FEATURE_PV_EOI))
+ wrmsrl(MSR_KVM_PV_EOI_EN, 0);
+ kvm_pv_disable_apf();
+ if (!shutdown)
+ apf_task_wake_all();
+ kvmclock_disable();
+}
+
+static int kvm_cpu_online(unsigned int cpu)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ kvm_guest_cpu_init();
+ local_irq_restore(flags);
+ return 0;
+}
+
#ifdef CONFIG_SMP
static DEFINE_PER_CPU(cpumask_var_t, __pv_cpu_mask);
@@ -635,31 +633,64 @@ static void __init kvm_smp_prepare_boot_cpu(void)
kvm_spinlock_init();
}
-static void kvm_guest_cpu_offline(void)
+static int kvm_cpu_down_prepare(unsigned int cpu)
{
- kvm_disable_steal_time();
- if (kvm_para_has_feature(KVM_FEATURE_PV_EOI))
- wrmsrl(MSR_KVM_PV_EOI_EN, 0);
- kvm_pv_disable_apf();
- apf_task_wake_all();
+ unsigned long flags;
+
+ local_irq_save(flags);
+ kvm_guest_cpu_offline(false);
+ local_irq_restore(flags);
+ return 0;
}
-static int kvm_cpu_online(unsigned int cpu)
+#endif
+
+static int kvm_suspend(void)
{
- local_irq_disable();
- kvm_guest_cpu_init();
- local_irq_enable();
+ kvm_guest_cpu_offline(false);
+
return 0;
}
-static int kvm_cpu_down_prepare(unsigned int cpu)
+static void kvm_resume(void)
{
- local_irq_disable();
- kvm_guest_cpu_offline();
- local_irq_enable();
- return 0;
+ kvm_cpu_online(raw_smp_processor_id());
+}
+
+static struct syscore_ops kvm_syscore_ops = {
+ .suspend = kvm_suspend,
+ .resume = kvm_resume,
+};
+
+static void kvm_pv_guest_cpu_reboot(void *unused)
+{
+ kvm_guest_cpu_offline(true);
+}
+
+static int kvm_pv_reboot_notify(struct notifier_block *nb,
+ unsigned long code, void *unused)
+{
+ if (code == SYS_RESTART)
+ on_each_cpu(kvm_pv_guest_cpu_reboot, NULL, 1);
+ return NOTIFY_DONE;
}
+static struct notifier_block kvm_pv_reboot_nb = {
+ .notifier_call = kvm_pv_reboot_notify,
+};
+
+/*
+ * After a PV feature is registered, the host will keep writing to the
+ * registered memory location. If the guest happens to shutdown, this memory
+ * won't be valid. In cases like kexec, in which you install a new kernel, this
+ * means a random memory location will be kept being written.
+ */
+#ifdef CONFIG_KEXEC_CORE
+static void kvm_crash_shutdown(struct pt_regs *regs)
+{
+ kvm_guest_cpu_offline(true);
+ native_machine_crash_shutdown(regs);
+}
#endif
static void __init kvm_guest_init(void)
@@ -704,6 +735,12 @@ static void __init kvm_guest_init(void)
kvm_guest_cpu_init();
#endif
+#ifdef CONFIG_KEXEC_CORE
+ machine_ops.crash_shutdown = kvm_crash_shutdown;
+#endif
+
+ register_syscore_ops(&kvm_syscore_ops);
+
/*
* Hard lockup detection is enabled by default. Disable it, as guests
* can get false positives too easily, for example if the host is