linux-kernel - [PATCH RFC 5/7] x86/kvm/mmu: get rid of redundant kvm_mmu

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Date:   Fri, 20 Jul 2018 15:26:24 +0200
From:   Vitaly Kuznetsov <vkuznets@...hat.com>
To:     kvm@...r.kernel.org
Cc:     Paolo Bonzini <pbonzini@...hat.com>,
        Radim Krčmář <rkrcmar@...hat.com>,
        Jim Mattson <jmattson@...gle.com>,
        Liran Alon <liran.alon@...cle.com>,
        linux-kernel@...r.kernel.org
Subject: [PATCH RFC 5/7] x86/kvm/mmu: get rid of redundant kvm_mmu_setup()

kvm_mmu_setup() is used only once in kvm_arch_vcpu_setup() and
kvm_mmu_reset_context() is good enough: we have no root to free so the end
result is not any different. init_kvm_mmu() can now be dropped too.

This is a preparatory change to optimizing kvm_mmu_reset_context().

Signed-off-by: Vitaly Kuznetsov <vkuznets@...hat.com>
---
 arch/x86/include/asm/kvm_host.h |  1 -
 arch/x86/kvm/mmu.c              | 17 +++--------------
 arch/x86/kvm/x86.c              |  2 +-
 3 files changed, 4 insertions(+), 16 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 3d0d26142619..2c0b493e09f7 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1128,7 +1128,6 @@ void kvm_mmu_module_exit(void);
 
 void kvm_mmu_destroy(struct kvm_vcpu *vcpu);
 int kvm_mmu_create(struct kvm_vcpu *vcpu);
-void kvm_mmu_setup(struct kvm_vcpu *vcpu);
 void kvm_mmu_init_vm(struct kvm *kvm);
 void kvm_mmu_uninit_vm(struct kvm *kvm);
 void kvm_mmu_set_mask_ptes(u64 user_mask, u64 accessed_mask,
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 76849eda1a5b..fb6652643b15 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -4633,8 +4633,10 @@ static void init_kvm_nested_mmu(struct kvm_vcpu *vcpu)
 	update_last_nonleaf_level(vcpu, g_context);
 }
 
-static void init_kvm_mmu(struct kvm_vcpu *vcpu)
+void kvm_mmu_reset_context(struct kvm_vcpu *vcpu)
 {
+	kvm_mmu_unload(vcpu);
+
 	if (mmu_is_nested(vcpu))
 		init_kvm_nested_mmu(vcpu);
 	else if (tdp_enabled)
@@ -4642,12 +4644,6 @@ static void init_kvm_mmu(struct kvm_vcpu *vcpu)
 	else
 		init_kvm_softmmu(vcpu);
 }
-
-void kvm_mmu_reset_context(struct kvm_vcpu *vcpu)
-{
-	kvm_mmu_unload(vcpu);
-	init_kvm_mmu(vcpu);
-}
 EXPORT_SYMBOL_GPL(kvm_mmu_reset_context);
 
 int kvm_mmu_load(struct kvm_vcpu *vcpu)
@@ -5062,13 +5058,6 @@ int kvm_mmu_create(struct kvm_vcpu *vcpu)
 	return alloc_mmu_pages(vcpu);
 }
 
-void kvm_mmu_setup(struct kvm_vcpu *vcpu)
-{
-	MMU_WARN_ON(VALID_PAGE(vcpu->arch.mmu->root_hpa));
-
-	init_kvm_mmu(vcpu);
-}
-
 static void kvm_mmu_invalidate_zap_pages_in_memslot(struct kvm *kvm,
 			struct kvm_memory_slot *slot,
 			struct kvm_page_track_notifier_node *node)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index a98fafd6ac24..5510a7f50195 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -8333,7 +8333,7 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
 	kvm_vcpu_mtrr_init(vcpu);
 	vcpu_load(vcpu);
 	kvm_vcpu_reset(vcpu, false);
-	kvm_mmu_setup(vcpu);
+	kvm_mmu_reset_context(vcpu);
 	vcpu_put(vcpu);
 	return 0;
 }
-- 
2.14.4