linux-kernel - [PATCH 01/10] KVM: x86: extract block/allow guest enteries

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Date:   Wed, 23 Jun 2021 14:29:53 +0300
From:   Maxim Levitsky <mlevitsk@...hat.com>
To:     kvm@...r.kernel.org
Cc:     Thomas Gleixner <tglx@...utronix.de>,
        Sean Christopherson <seanjc@...gle.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Joerg Roedel <joro@...tes.org>, Borislav Petkov <bp@...en8.de>,
        "H. Peter Anvin" <hpa@...or.com>, Ingo Molnar <mingo@...hat.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        linux-kernel@...r.kernel.org (open list:X86 ARCHITECTURE (32-BIT AND
        64-BIT)),
        x86@...nel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)),
        Jim Mattson <jmattson@...gle.com>,
        Maxim Levitsky <mlevitsk@...hat.com>
Subject: [PATCH 01/10] KVM: x86: extract block/allow guest enteries

Master clock update sets and then clears a request which is not
handled by KVM as a means to block and then allow guest entries.
Extract this to kvm_allow_guest_entries/kvm_block_guest_entries.

No functional change intended.

Signed-off-by: Maxim Levitsky <mlevitsk@...hat.com>
---
 arch/x86/include/asm/kvm_host.h |  5 +++--
 arch/x86/kvm/x86.c              | 25 +++++++++++++++----------
 2 files changed, 18 insertions(+), 12 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index e11d64aa0bcd..cadb09c6fb0e 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -68,7 +68,7 @@
 #define KVM_REQ_PMI			KVM_ARCH_REQ(11)
 #define KVM_REQ_SMI			KVM_ARCH_REQ(12)
 #define KVM_REQ_MASTERCLOCK_UPDATE	KVM_ARCH_REQ(13)
-#define KVM_REQ_MCLOCK_INPROGRESS \
+#define KVM_REQ_BLOCK_GUEST_ENTRIES \
 	KVM_ARCH_REQ_FLAGS(14, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
 #define KVM_REQ_SCAN_IOAPIC \
 	KVM_ARCH_REQ_FLAGS(15, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
@@ -1831,7 +1831,8 @@ u64 kvm_calc_nested_tsc_multiplier(u64 l1_multiplier, u64 l2_multiplier);
 unsigned long kvm_get_linear_rip(struct kvm_vcpu *vcpu);
 bool kvm_is_linear_rip(struct kvm_vcpu *vcpu, unsigned long linear_rip);
 
-void kvm_make_mclock_inprogress_request(struct kvm *kvm);
+void kvm_block_guest_entries(struct kvm *kvm);
+void kvm_allow_guest_entries(struct kvm *kvm);
 void kvm_make_scan_ioapic_request(struct kvm *kvm);
 void kvm_make_scan_ioapic_request_mask(struct kvm *kvm,
 				       unsigned long *vcpu_bitmap);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 76dae88cf524..9af2fbbe0521 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2735,9 +2735,18 @@ static void pvclock_update_vm_gtod_copy(struct kvm *kvm)
 #endif
 }
 
-void kvm_make_mclock_inprogress_request(struct kvm *kvm)
+void kvm_block_guest_entries(struct kvm *kvm)
 {
-	kvm_make_all_cpus_request(kvm, KVM_REQ_MCLOCK_INPROGRESS);
+	kvm_make_all_cpus_request(kvm, KVM_REQ_BLOCK_GUEST_ENTRIES);
+}
+
+void kvm_allow_guest_entries(struct kvm *kvm)
+{
+	struct kvm_vcpu *vcpu;
+	int i;
+
+	kvm_for_each_vcpu(i, vcpu, kvm)
+		kvm_clear_request(KVM_REQ_BLOCK_GUEST_ENTRIES, vcpu);
 }
 
 static void kvm_gen_update_masterclock(struct kvm *kvm)
@@ -2750,9 +2759,8 @@ static void kvm_gen_update_masterclock(struct kvm *kvm)
 
 	kvm_hv_invalidate_tsc_page(kvm);
 
-	kvm_make_mclock_inprogress_request(kvm);
+	kvm_block_guest_entries(kvm);
 
-	/* no guest entries from this point */
 	spin_lock_irqsave(&ka->pvclock_gtod_sync_lock, flags);
 	pvclock_update_vm_gtod_copy(kvm);
 	spin_unlock_irqrestore(&ka->pvclock_gtod_sync_lock, flags);
@@ -2760,9 +2768,7 @@ static void kvm_gen_update_masterclock(struct kvm *kvm)
 	kvm_for_each_vcpu(i, vcpu, kvm)
 		kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
 
-	/* guest entries allowed */
-	kvm_for_each_vcpu(i, vcpu, kvm)
-		kvm_clear_request(KVM_REQ_MCLOCK_INPROGRESS, vcpu);
+	kvm_allow_guest_entries(kvm);
 #endif
 }
 
@@ -8051,7 +8057,7 @@ static void kvm_hyperv_tsc_notifier(void)
 
 	mutex_lock(&kvm_lock);
 	list_for_each_entry(kvm, &vm_list, vm_list)
-		kvm_make_mclock_inprogress_request(kvm);
+		kvm_block_guest_entries(kvm);
 
 	hyperv_stop_tsc_emulation();
 
@@ -8070,8 +8076,7 @@ static void kvm_hyperv_tsc_notifier(void)
 		kvm_for_each_vcpu(cpu, vcpu, kvm)
 			kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
 
-		kvm_for_each_vcpu(cpu, vcpu, kvm)
-			kvm_clear_request(KVM_REQ_MCLOCK_INPROGRESS, vcpu);
+		kvm_allow_guest_entries(kvm);
 	}
 	mutex_unlock(&kvm_lock);
 }
-- 
2.26.3