Add KVM suspend/hibernate PM-notifier which lets architectures
to implement arch-specific VM suspend code. For instance, on x86
this sets PVCLOCK_GUEST_STOPPED on all the VCPUs.

Our case is that user puts the host system into sleep multiple
times a day (e.g. closes the laptop's lid) so we need a reliable
way to suspend VMs properly.

Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
---
 arch/arm64/kvm/arm.c       |  4 ++++
 arch/mips/kvm/mips.c       |  4 ++++
 arch/powerpc/kvm/powerpc.c |  4 ++++
 arch/s390/kvm/kvm-s390.c   |  4 ++++
 arch/x86/kvm/x86.c         | 21 ++++++++++++++++++++
 include/linux/kvm_host.h   |  8 ++++++++
 virt/kvm/kvm_main.c        | 40 ++++++++++++++++++++++++++++++++++++++
 7 files changed, 85 insertions(+)

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 1126eae27400..547dbe44d039 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c

@@ -1311,6 +1311,10 @@ static int kvm_vm_ioctl_set_device_addr(struct kvm *kvm,
 	}
 }
 
+void kvm_arch_pm_notifier(struct kvm *kvm)
+{
+}
+
 long kvm_arch_vm_ioctl(struct file *filp,
 		       unsigned int ioctl, unsigned long arg)
 {

diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index 4d4af97dcc88..d4408acd2be6 100644
--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c

@@ -980,6 +980,10 @@ void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm,
 	kvm_flush_remote_tlbs(kvm);
 }
 
+void kvm_arch_pm_notifier(struct kvm *kvm)
+{
+}
+
 long kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)
 {
 	long r;

diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index a2a68a958fa0..96e8a7b6fcf0 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c

@@ -2334,6 +2334,10 @@ static int kvmppc_get_cpu_char(struct kvm_ppc_cpu_char *cp)
 }
 #endif
 
+void kvm_arch_pm_notifier(struct kvm *kvm)
+{
+}
+
 long kvm_arch_vm_ioctl(struct file *filp,
                        unsigned int ioctl, unsigned long arg)
 {

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 1296fc10f80c..c5f86fc1e497 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c

@@ -2367,6 +2367,10 @@ static int kvm_s390_handle_pv(struct kvm *kvm, struct kvm_pv_cmd *cmd)
 	return r;
 }
 
+void kvm_arch_pm_notifier(struct kvm *kvm)
+{
+}
+
 long kvm_arch_vm_ioctl(struct file *filp,
 		       unsigned int ioctl, unsigned long arg)
 {