kvm: add PM-notifier

Add KVM PM-notifier so that architectures can have arch-specific
VM suspend/resume routines. Such architectures need to select
CONFIG_HAVE_KVM_PM_NOTIFIER and implement kvm_arch_pm_notifier().

Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Acked-by: Marc Zyngier <maz@kernel.org>
Message-Id: <20210606021045.14159-1-senozhatsky@chromium.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 11b9b11a5e9b06417e781cad0a7cff155fd1880f..37cbb56ccd09c8b8e976c7aa7431c53b3aad801f 100644 (file)
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -28,6 +28,7 @@
 #include <linux/rcuwait.h>
 #include <linux/refcount.h>
 #include <linux/nospec.h>
+#include <linux/notifier.h>
 #include <asm/signal.h>
 
 #include <linux/kvm.h>
@@ -594,6 +595,10 @@ struct kvm {
        pid_t userspace_pid;
        unsigned int max_halt_poll_ns;
        u32 dirty_ring_size;
+
+#ifdef CONFIG_HAVE_KVM_PM_NOTIFIER
+       struct notifier_block pm_notifier;
+#endif
 };
 
 #define kvm_err(fmt, ...) \
@@ -1007,6 +1012,10 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu);
 void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu);
 void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu);
 
+#ifdef CONFIG_HAVE_KVM_PM_NOTIFIER
+int kvm_arch_pm_notifier(struct kvm *kvm, unsigned long state);
+#endif
+
 #ifdef __KVM_HAVE_ARCH_VCPU_DEBUGFS
 void kvm_arch_create_vcpu_debugfs(struct kvm_vcpu *vcpu, struct dentry *debugfs_dentry);
 #endif

diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig
index 1c37ccd5d402a663eac946b21e6a2ba2e95efbaa..62b39149b8c82b901a7cb2b975a89dc9ed31d6b8 100644 (file)
--- a/virt/kvm/Kconfig
+++ b/virt/kvm/Kconfig
@@ -63,3 +63,6 @@ config HAVE_KVM_NO_POLL
 
 config KVM_XFER_TO_GUEST_WORK
        bool
+
+config HAVE_KVM_PM_NOTIFIER
+       bool

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index fa7e7ebefc7962dc767abfa991001cfa0f89e104..fc35ba0ea5d3b0a245e81849c278b6913ae5e8d7 100644 (file)
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -51,6 +51,7 @@
 #include <linux/io.h>
 #include <linux/lockdep.h>
 #include <linux/kthread.h>
+#include <linux/suspend.h>
 
 #include <asm/processor.h>
 #include <asm/ioctl.h>
@@ -780,6 +781,38 @@ static int kvm_init_mmu_notifier(struct kvm *kvm)
 
 #endif /* CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER */
 
+#ifdef CONFIG_HAVE_KVM_PM_NOTIFIER
+static int kvm_pm_notifier_call(struct notifier_block *bl,
+                               unsigned long state,
+                               void *unused)
+{
+       struct kvm *kvm = container_of(bl, struct kvm, pm_notifier);
+
+       return kvm_arch_pm_notifier(kvm, state);
+}
+
+static void kvm_init_pm_notifier(struct kvm *kvm)
+{
+       kvm->pm_notifier.notifier_call = kvm_pm_notifier_call;
+       /* Suspend KVM before we suspend ftrace, RCU, etc. */
+       kvm->pm_notifier.priority = INT_MAX;
+       register_pm_notifier(&kvm->pm_notifier);
+}
+
+static void kvm_destroy_pm_notifier(struct kvm *kvm)
+{
+       unregister_pm_notifier(&kvm->pm_notifier);
+}
+#else /* !CONFIG_HAVE_KVM_PM_NOTIFIER */
+static void kvm_init_pm_notifier(struct kvm *kvm)
+{
+}
+
+static void kvm_destroy_pm_notifier(struct kvm *kvm)
+{
+}
+#endif /* CONFIG_HAVE_KVM_PM_NOTIFIER */
+
 static struct kvm_memslots *kvm_alloc_memslots(void)
 {
        int i;
@@ -964,6 +997,7 @@ static struct kvm *kvm_create_vm(unsigned long type)
        mutex_unlock(&kvm_lock);
 
        preempt_notifier_inc();
+       kvm_init_pm_notifier(kvm);
 
        return kvm;
 
@@ -1011,6 +1045,7 @@ static void kvm_destroy_vm(struct kvm *kvm)
        int i;
        struct mm_struct *mm = kvm->mm;
 
+       kvm_destroy_pm_notifier(kvm);
        kvm_uevent_notify_change(KVM_EVENT_DESTROY_VM, kvm);
        kvm_destroy_vm_debugfs(kvm);
        kvm_arch_sync_events(kvm);