linux-kernel - [PATCH 1/1] KVM: x86: remove always-false condition in kvmclock_sync

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Message-Id: <20231001213637.76686-1-dongli.zhang@oracle.com>
Date:   Sun,  1 Oct 2023 14:36:37 -0700
From:   Dongli Zhang <dongli.zhang@...cle.com>
To:     kvm@...r.kernel.org, x86@...nel.org
Cc:     linux-kernel@...r.kernel.org, seanjc@...gle.com,
        pbonzini@...hat.com, tglx@...utronix.de, mingo@...hat.com,
        bp@...en8.de, dave.hansen@...ux.intel.com
Subject: [PATCH 1/1] KVM: x86: remove always-false condition in kvmclock_sync_fn

The 'kvmclock_periodic_sync' is a readonly param that cannot change after
bootup.

The kvm_arch_vcpu_postcreate() is not going to schedule the
kvmclock_sync_work if kvmclock_periodic_sync == false.

As a result, the "if (!kvmclock_periodic_sync)" can never be true if the
kvmclock_sync_work = kvmclock_sync_fn() is scheduled.

Inspired by: https://lore.kernel.org/kvm/a461bf3f-c17e-9c3f-56aa-726225e8391d@oracle.com/
Signed-off-by: Dongli Zhang <dongli.zhang@...cle.com>
---
 arch/x86/kvm/x86.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 9f18b06bbda6..38fd04a286c7 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3290,9 +3290,6 @@ static void kvmclock_sync_fn(struct work_struct *work)
 					   kvmclock_sync_work);
 	struct kvm *kvm = container_of(ka, struct kvm, arch);
 
-	if (!kvmclock_periodic_sync)
-		return;
-
 	schedule_delayed_work(&kvm->arch.kvmclock_update_work, 0);
 	schedule_delayed_work(&kvm->arch.kvmclock_sync_work,
 					KVMCLOCK_SYNC_PERIOD);
-- 
2.34.1