[PATCH 5/5] x86/kvm: Unify kvm_pv_guest_cpu_reboot() with kvm_guest_cpu_offline()

From: Vitaly Kuznetsov
Date: Wed Apr 14 2021 - 08:36:36 EST


Simplify the code by making PV features shutdown happen in one place.

Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
---
arch/x86/kernel/kvm.c | 42 +++++++++++++++++-------------------------
1 file changed, 17 insertions(+), 25 deletions(-)

diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index 1754b7c3f754..7da7bea96745 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -384,31 +384,6 @@ static void kvm_disable_steal_time(void)
wrmsr(MSR_KVM_STEAL_TIME, 0, 0);
}

-static void kvm_pv_guest_cpu_reboot(void *unused)
-{
- /*
- * 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();
-}
-
-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,
-};
-
static u64 kvm_steal_clock(int cpu)
{
u64 steal;
@@ -664,6 +639,23 @@ static struct syscore_ops kvm_syscore_ops = {
.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
--
2.30.2