linux-kernel - [PATCH v6 1/5] Revert "KVM: X86: Fix setup the virt_spin_lock

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Date:   Tue, 15 Oct 2019 09:19:23 +0800
From:   Zhenzhong Duan <zhenzhong.duan@...cle.com>
To:     linux-kernel@...r.kernel.org
Cc:     vkuznets@...hat.com, linux-hyperv@...r.kernel.org,
        kvm@...r.kernel.org, kys@...rosoft.com, haiyangz@...rosoft.com,
        sthemmin@...rosoft.com, sashal@...nel.org, tglx@...utronix.de,
        mingo@...hat.com, bp@...en8.de, pbonzini@...hat.com,
        rkrcmar@...hat.com, sean.j.christopherson@...el.com,
        wanpengli@...cent.com, jmattson@...gle.com, joro@...tes.org,
        boris.ostrovsky@...cle.com, jgross@...e.com,
        sstabellini@...nel.org, peterz@...radead.org,
        Zhenzhong Duan <zhenzhong.duan@...cle.com>,
        "H. Peter Anvin" <hpa@...or.com>
Subject: [PATCH v6 1/5] Revert "KVM: X86: Fix setup the virt_spin_lock_key before static key get initialized"

This reverts commit 34226b6b70980a8f81fff3c09a2c889f77edeeff.

Commit 8990cac6e5ea ("x86/jump_label: Initialize static branching
early") adds jump_label_init() call in setup_arch() to make static
keys initialized early, so we could use the original simpler code
again.

The similar change for XEN is in commit 090d54bcbc54 ("Revert
"x86/paravirt: Set up the virt_spin_lock_key after static keys get
initialized"")

Signed-off-by: Zhenzhong Duan <zhenzhong.duan@...cle.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@...hat.com>
Cc: Paolo Bonzini <pbonzini@...hat.com>
Cc: Radim Krcmar <rkrcmar@...hat.com>
Cc: Sean Christopherson <sean.j.christopherson@...el.com>
Cc: Vitaly Kuznetsov <vkuznets@...hat.com>
Cc: Wanpeng Li <wanpengli@...cent.com>
Cc: Jim Mattson <jmattson@...gle.com>
Cc: Joerg Roedel <joro@...tes.org>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: Ingo Molnar <mingo@...hat.com>
Cc: Borislav Petkov <bp@...en8.de>
Cc: "H. Peter Anvin" <hpa@...or.com>
---
 arch/x86/kernel/kvm.c | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index e820568..3bc6a266 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -527,13 +527,6 @@ static void kvm_smp_send_call_func_ipi(const struct cpumask *mask)
 	}
 }
 
-static void __init kvm_smp_prepare_cpus(unsigned int max_cpus)
-{
-	native_smp_prepare_cpus(max_cpus);
-	if (kvm_para_has_hint(KVM_HINTS_REALTIME))
-		static_branch_disable(&virt_spin_lock_key);
-}
-
 static void __init kvm_smp_prepare_boot_cpu(void)
 {
 	/*
@@ -633,7 +626,6 @@ static void __init kvm_guest_init(void)
 		apic_set_eoi_write(kvm_guest_apic_eoi_write);
 
 #ifdef CONFIG_SMP
-	smp_ops.smp_prepare_cpus = kvm_smp_prepare_cpus;
 	smp_ops.smp_prepare_boot_cpu = kvm_smp_prepare_boot_cpu;
 	if (kvm_para_has_feature(KVM_FEATURE_PV_SCHED_YIELD) &&
 	    !kvm_para_has_hint(KVM_HINTS_REALTIME) &&
@@ -835,8 +827,10 @@ void __init kvm_spinlock_init(void)
 	if (!kvm_para_has_feature(KVM_FEATURE_PV_UNHALT))
 		return;
 
-	if (kvm_para_has_hint(KVM_HINTS_REALTIME))
+	if (kvm_para_has_hint(KVM_HINTS_REALTIME)) {
+		static_branch_disable(&virt_spin_lock_key);
 		return;
+	}
 
 	/* Don't use the pvqspinlock code if there is only 1 vCPU. */
 	if (num_possible_cpus() == 1)
-- 
1.8.3.1