| Message ID | 20240530210714.364118-6-rick.p.edgecombe@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | TDX MMU prep series part 1 | expand |
On Thu, May 30, 2024 at 11:07 PM Rick Edgecombe <rick.p.edgecombe@intel.com> wrote: > > 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> > --- > TDX MMU Prep: > - New patch > --- > arch/x86/kvm/mmu/mmu.c | 6 ++++-- > arch/x86/kvm/mmu/tdp_mmu.c | 3 +-- > arch/x86/kvm/mmu/tdp_mmu.h | 2 +- > 3 files changed, 6 insertions(+), 5 deletions(-) > > diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c > index 5070ba7c6e89..12178945922f 100644 > --- a/arch/x86/kvm/mmu/mmu.c > +++ b/arch/x86/kvm/mmu/mmu.c > @@ -3700,8 +3700,10 @@ 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 e7cd4921afe7..2770230a5636 100644 > --- 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 @@ int kvm_tdp_mmu_alloc_root(struct kvm_vcpu *vcpu) > */ > 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 58b55e61bd33..437ddd4937a9 100644 > --- 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) > { > -- > 2.34.1 >
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 5070ba7c6e89..12178945922f 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -3700,8 +3700,10 @@ 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 e7cd4921afe7..2770230a5636 100644 --- 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 @@ int kvm_tdp_mmu_alloc_root(struct kvm_vcpu *vcpu) */ 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 58b55e61bd33..437ddd4937a9 100644 --- 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) {
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> --- TDX MMU Prep: - New patch --- arch/x86/kvm/mmu/mmu.c | 6 ++++-- arch/x86/kvm/mmu/tdp_mmu.c | 3 +-- arch/x86/kvm/mmu/tdp_mmu.h | 2 +- 3 files changed, 6 insertions(+), 5 deletions(-)