KVM: MMU: stop dereferencing vcpu->arch.mmu to get the context for MMU init

kvm_init_shadow_mmu() was actually the only function that could be called
with different vcpu->arch.mmu values.  Now that kvm_init_shadow_npt_mmu()
is separated from kvm_init_shadow_mmu(), we always know the MMU context
we need to use and there is no need to dereference vcpu->arch.mmu pointer.

Based on a patch by Vitaly Kuznetsov <vkuznets@redhat.com>.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20200710141157.1640173-3-vkuznets@redhat.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 f6e032c..78c88e8 100644 (file)
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -4850,7 +4850,7 @@ kvm_calc_tdp_mmu_root_page_role(struct kvm_vcpu *vcpu, bool base_only)
 
 static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu)
 {
-       struct kvm_mmu *context = vcpu->arch.mmu;
+       struct kvm_mmu *context = &vcpu->arch.root_mmu;
        union kvm_mmu_role new_role =
                kvm_calc_tdp_mmu_root_page_role(vcpu, false);
 
@@ -4918,11 +4918,10 @@ kvm_calc_shadow_mmu_root_page_role(struct kvm_vcpu *vcpu, bool base_only)
        return role;
 }
 
-static void shadow_mmu_init_context(struct kvm_vcpu *vcpu, u32 cr0, u32 cr4,
-                                   u32 efer, union kvm_mmu_role new_role)
+static void shadow_mmu_init_context(struct kvm_vcpu *vcpu, struct kvm_mmu *context,
+                                   u32 cr0, u32 cr4, u32 efer,
+                                   union kvm_mmu_role new_role)
 {
-       struct kvm_mmu *context = vcpu->arch.mmu;
-
        if (!(cr0 & X86_CR0_PG))
                nonpaging_init_context(vcpu, context);
        else if (efer & EFER_LMA)
@@ -4938,23 +4937,23 @@ static void shadow_mmu_init_context(struct kvm_vcpu *vcpu, u32 cr0, u32 cr4,
 
 static void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu, u32 cr0, u32 cr4, u32 efer)
 {
-       struct kvm_mmu *context = vcpu->arch.mmu;
+       struct kvm_mmu *context = &vcpu->arch.root_mmu;
        union kvm_mmu_role new_role =
                kvm_calc_shadow_mmu_root_page_role(vcpu, false);
 
        if (new_role.as_u64 != context->mmu_role.as_u64)
-               shadow_mmu_init_context(vcpu, cr0, cr4, efer, new_role);
+               shadow_mmu_init_context(vcpu, context, cr0, cr4, efer, new_role);
 }
 
 void kvm_init_shadow_npt_mmu(struct kvm_vcpu *vcpu, u32 cr0, u32 cr4, u32 efer,
                             gpa_t nested_cr3)
 {
-       struct kvm_mmu *context = vcpu->arch.mmu;
+       struct kvm_mmu *context = &vcpu->arch.guest_mmu;
        union kvm_mmu_role new_role =
                kvm_calc_shadow_mmu_root_page_role(vcpu, false);
 
        if (new_role.as_u64 != context->mmu_role.as_u64)
-               shadow_mmu_init_context(vcpu, cr0, cr4, efer, new_role);
+               shadow_mmu_init_context(vcpu, context, cr0, cr4, efer, new_role);
 }
 EXPORT_SYMBOL_GPL(kvm_init_shadow_npt_mmu);
 
@@ -4990,7 +4989,7 @@ kvm_calc_shadow_ept_root_page_role(struct kvm_vcpu *vcpu, bool accessed_dirty,
 void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly,
                             bool accessed_dirty, gpa_t new_eptp)
 {
-       struct kvm_mmu *context = vcpu->arch.mmu;
+       struct kvm_mmu *context = &vcpu->arch.guest_mmu;
        u8 level = vmx_eptp_page_walk_level(new_eptp);
        union kvm_mmu_role new_role =
                kvm_calc_shadow_ept_root_page_role(vcpu, accessed_dirty,
@@ -5024,7 +5023,7 @@ EXPORT_SYMBOL_GPL(kvm_init_shadow_ept_mmu);
 
 static void init_kvm_softmmu(struct kvm_vcpu *vcpu)
 {
-       struct kvm_mmu *context = vcpu->arch.mmu;
+       struct kvm_mmu *context = &vcpu->arch.root_mmu;
 
        kvm_init_shadow_mmu(vcpu,
                            kvm_read_cr0_bits(vcpu, X86_CR0_PG),