[PATCH v3 2/9] KVM: nSVM: stop dereferencing vcpu->arch.mmu to get the context in kvm_init_shadow{,_npt}_mmu()

Vitaly Kuznetsov
2020-07-09T14:54:17Z

Now as kvm_init_shadow_npt_mmu() is separated from kvm_init_shadow_mmu()
we always know the MMU context we need to use so there is no need to
dereference vcpu->arch.mmu pointer.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
arch/x86/kvm/mmu/mmu.c | 15 +++++++--------
1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 93f18e5fa8b5..69fa51af8cbf 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -4952,11 +4952,10 @@ 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)
@@ -4972,23 +4971,23 @@ 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);

--
2.25.4