[PATCH 19/23] KVM: MMU: simplify and/or inline computation of shadow MMU roles

Paolo Bonzini
2022-02-04T11:58:18Z

Shadow MMUs can compute their role from cpu_role.base, simply by adjusting
the root level. It's one line of code, so do not place it in a separate
function.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/kvm/mmu/mmu.c | 32 +++++++-------------------------
1 file changed, 7 insertions(+), 25 deletions(-)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index bba712d1a6d7..01027da82e23 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -4755,20 +4755,6 @@ static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu,
reset_tdp_shadow_zero_bits_mask(context);
}

-static union kvm_mmu_page_role
-kvm_calc_shadow_mmu_root_page_role(struct kvm_vcpu *vcpu,
- union kvm_mmu_role role)
-{
- if (!role.ext.efer_lma)
- role.base.level = PT32E_ROOT_LEVEL;
- else if (role.ext.cr4_la57)
- role.base.level = PT64_ROOT_5LEVEL;
- else
- role.base.level = PT64_ROOT_4LEVEL;
-
- return role.base;
-}
-
static void shadow_mmu_init_context(struct kvm_vcpu *vcpu, struct kvm_mmu *context,
union kvm_mmu_role cpu_role,
union kvm_mmu_page_role mmu_role)
@@ -4797,9 +4783,10 @@ static void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu,
{
struct kvm_mmu *context = &vcpu->arch.root_mmu;
union kvm_mmu_role cpu_role = kvm_calc_cpu_role(vcpu, regs);
- union kvm_mmu_page_role mmu_role =
- kvm_calc_shadow_mmu_root_page_role(vcpu, cpu_role);
+ union kvm_mmu_page_role mmu_role;

+ mmu_role = cpu_role.base;
+ mmu_role.level = max_t(u32, mmu_role.level, PT32E_ROOT_LEVEL);
shadow_mmu_init_context(vcpu, context, cpu_role, mmu_role);

/*
@@ -4813,14 +4800,6 @@ static void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu,
reset_shadow_zero_bits_mask(vcpu, context);
}

-static union kvm_mmu_page_role
-kvm_calc_shadow_npt_root_page_role(struct kvm_vcpu *vcpu,
- union kvm_mmu_role role)
-{
- role.base.level = kvm_mmu_get_tdp_level(vcpu);
- return role.base;
-}
-
void kvm_init_shadow_npt_mmu(struct kvm_vcpu *vcpu, unsigned long cr0,
unsigned long cr4, u64 efer, gpa_t nested_cr3)
{
@@ -4831,7 +4810,10 @@ void kvm_init_shadow_npt_mmu(struct kvm_vcpu *vcpu, unsigned long cr0,
.efer = efer,
};
union kvm_mmu_role cpu_role = kvm_calc_cpu_role(vcpu, &regs);
- union kvm_mmu_page_role mmu_role = kvm_calc_shadow_npt_root_page_role(vcpu, cpu_role);
+ union kvm_mmu_page_role mmu_role;
+
+ mmu_role = cpu_role.base;
+ mmu_role.level = kvm_mmu_get_tdp_level(vcpu);

shadow_mmu_init_context(vcpu, context, cpu_role, mmu_role);
reset_shadow_zero_bits_mask(vcpu, context);
--
2.31.1