KVM: x86/mmu: Make kvm_tdp_mmu_alloc_root() return void

The kvm_tdp_mmu_alloc_root() function currently always returns 0. This
allows for the caller, mmu_alloc_direct_roots(), to call
kvm_tdp_mmu_alloc_root() and also return 0 in one line:
   return kvm_tdp_mmu_alloc_root(vcpu);

So it is useful even though the return value of kvm_tdp_mmu_alloc_root()
is always the same. However, in future changes, kvm_tdp_mmu_alloc_root()
will be called twice in mmu_alloc_direct_roots(). This will force the
first call to either awkwardly handle the return value that will always
be zero or ignore it. So change kvm_tdp_mmu_alloc_root() to return void.
Do it in a separate change so the future change will be cleaner.

Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20240718211230.1492011-7-rick.p.edgecombe@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index d44d0a4db69962c04ea7fba025d0601372285d13..cbb77ef5689819b741995cdd30a5a5fbbd0011a3 100644 (file)
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -3663,8 +3663,10 @@ static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu)
        unsigned i;
        int r;
 
-       if (tdp_mmu_enabled)
-               return kvm_tdp_mmu_alloc_root(vcpu);
+       if (tdp_mmu_enabled) {
+               kvm_tdp_mmu_alloc_root(vcpu);
+               return 0;
+       }
 
        write_lock(&vcpu->kvm->mmu_lock);
        r = make_mmu_pages_available(vcpu);

diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index d79a260d213dccf976943176d8ca79b0b408d9fb..d29c06cc86d773006aaaa996ee71a920d016f41f 100644 (file)
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -224,7 +224,7 @@ static void tdp_mmu_init_child_sp(struct kvm_mmu_page *child_sp,
        tdp_mmu_init_sp(child_sp, iter->sptep, iter->gfn, role);
 }
 
-int kvm_tdp_mmu_alloc_root(struct kvm_vcpu *vcpu)
+void kvm_tdp_mmu_alloc_root(struct kvm_vcpu *vcpu)
 {
        struct kvm_mmu *mmu = vcpu->arch.mmu;
        union kvm_mmu_page_role role = mmu->root_role;
@@ -285,7 +285,6 @@ out_read_unlock:
         */
        mmu->root.hpa = __pa(root->spt);
        mmu->root.pgd = 0;
-       return 0;
 }
 
 static void handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,

diff --git a/arch/x86/kvm/mmu/tdp_mmu.h b/arch/x86/kvm/mmu/tdp_mmu.h
index 6d7cdc462f58f3b9d5a65007f692622f50306928..51884fc6a512705ada2ba06a0b2090d99c77ebc9 100644 (file)
--- a/arch/x86/kvm/mmu/tdp_mmu.h
+++ b/arch/x86/kvm/mmu/tdp_mmu.h
@@ -10,7 +10,7 @@
 void kvm_mmu_init_tdp_mmu(struct kvm *kvm);
 void kvm_mmu_uninit_tdp_mmu(struct kvm *kvm);
 
-int kvm_tdp_mmu_alloc_root(struct kvm_vcpu *vcpu);
+void kvm_tdp_mmu_alloc_root(struct kvm_vcpu *vcpu);
 
 __must_check static inline bool kvm_tdp_mmu_get_root(struct kvm_mmu_page *root)
 {