This reverts commit 7e44e4495a398eb553ce561f29f9148f40a3448f.
Commit 7e44e4495a39 ("x86: kvm: rate-limit global clock updates")
intends to use a kvmclock_update_work to sync ntp corretion
across all vcpus kvmclock, which is based on commit 0061d53daf26f
("KVM: x86: limit difference between kvmclock updates")
Since kvmclock has been switched to mono raw, this commit can be
reverted.
Signed-off-by: Lei Chen <lei.chen@xxxxxxxxxx>
---
arch/x86/include/asm/kvm_host.h | 1 -
arch/x86/kvm/x86.c | 29 ++++-------------------------
2 files changed, 4 insertions(+), 26 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index e41e4fe91f5e..0a1165f40ff1 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1435,7 +1435,6 @@ struct kvm_arch {
bool use_master_clock;
u64 master_kernel_ns;
u64 master_cycle_now;
- struct delayed_work kvmclock_update_work;
#ifdef CONFIG_KVM_HYPERV
struct kvm_hv hyperv;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 399045a384d4..d526e9e285f1 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3404,22 +3404,14 @@ uint64_t kvm_get_wall_clock_epoch(struct kvm *kvm)
* the others.
*
* So in those cases, request a kvmclock update for all vcpus.
- * We need to rate-limit these requests though, as they can
- * considerably slow guests that have a large number of vcpus.
- * The time for a remote vcpu to update its kvmclock is bound
- * by the delay we use to rate-limit the updates.
+ * The worst case for a remote vcpu to update its kvmclock
+ * is then bounded by maximum nohz sleep latency.
*/
-
-#define KVMCLOCK_UPDATE_DELAY msecs_to_jiffies(100)
-
-static void kvmclock_update_fn(struct work_struct *work)
+static void kvm_gen_kvmclock_update(struct kvm_vcpu *v)
{
unsigned long i;
- struct delayed_work *dwork = to_delayed_work(work);
- struct kvm_arch *ka = container_of(dwork, struct kvm_arch,
- kvmclock_update_work);
- struct kvm *kvm = container_of(ka, struct kvm, arch);
struct kvm_vcpu *vcpu;
+ struct kvm *kvm = v->kvm;
kvm_for_each_vcpu(i, vcpu, kvm) {
kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
@@ -3427,15 +3419,6 @@ static void kvmclock_update_fn(struct work_struct *work)
}
}
-static void kvm_gen_kvmclock_update(struct kvm_vcpu *v)
-{
- struct kvm *kvm = v->kvm;
-
- kvm_make_request(KVM_REQ_CLOCK_UPDATE, v);
- schedule_delayed_work(&kvm->arch.kvmclock_update_work,
- KVMCLOCK_UPDATE_DELAY);
-}
-
/* These helpers are safe iff @msr is known to be an MCx bank MSR. */
static bool is_mci_control_msr(u32 msr)
{
@@ -12698,8 +12681,6 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
kvm->arch.hv_root_tdp = INVALID_PAGE;
#endif
- INIT_DELAYED_WORK(&kvm->arch.kvmclock_update_work, kvmclock_update_fn);
-
kvm_apicv_init(kvm);
kvm_hv_init_vm(kvm);
kvm_xen_init_vm(kvm);
@@ -12806,8 +12787,6 @@ void kvm_arch_pre_destroy_vm(struct kvm *kvm)
* is unsafe, i.e. will lead to use-after-free. The PIT also needs to
* be stopped before IRQ routing is freed.
*/
- cancel_delayed_work_sync(&kvm->arch.kvmclock_update_work);
-
#ifdef CONFIG_KVM_IOAPIC
kvm_free_pit(kvm);
#endif
--
2.44.0
