[PATCH v2 04/25] KVM: x86/mmu: pull computation of kvm_mmu_role_regs to kvm_init_mmu

Paolo Bonzini
2022-02-21T16:23:04Z

The init_kvm_*mmu functions, with the exception of shadow NPT,
do not need to know the full values of CR0/CR4/EFER; they only
need to know the bits that make up the "role". This cleanup
however will take quite a few incremental steps. As a start,
pull the common computation of the struct kvm_mmu_role_regs
into their caller: all of them extract the struct from the vcpu
as the very first step.

Reviewed-by: David Matlack <dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/kvm/mmu/mmu.c | 27 ++++++++++++++-------------
1 file changed, 14 insertions(+), 13 deletions(-)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 97566ac539e3..0e393506f4df 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -4753,12 +4753,12 @@ kvm_calc_tdp_mmu_root_page_role(struct kvm_vcpu *vcpu,
return role;
}

-static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu)
+static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu,
+ const struct kvm_mmu_role_regs *regs)
{
struct kvm_mmu *context = &vcpu->arch.root_mmu;
- struct kvm_mmu_role_regs regs = vcpu_to_role_regs(vcpu);
union kvm_mmu_role new_role =
- kvm_calc_tdp_mmu_root_page_role(vcpu, &regs, false);
+ kvm_calc_tdp_mmu_root_page_role(vcpu, regs, false);

if (new_role.as_u64 == context->mmu_role.as_u64)
return;
@@ -4772,7 +4772,7 @@ static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu)
context->get_guest_pgd = kvm_get_guest_cr3;
context->get_pdptr = kvm_pdptr_read;
context->inject_page_fault = kvm_inject_page_fault;
- context->root_level = role_regs_to_root_level(&regs);
+ context->root_level = role_regs_to_root_level(regs);

if (!is_cr0_pg(context))
context->gva_to_gpa = nonpaging_gva_to_gpa;
@@ -4941,12 +4941,12 @@ void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly,
}
EXPORT_SYMBOL_GPL(kvm_init_shadow_ept_mmu);

-static void init_kvm_softmmu(struct kvm_vcpu *vcpu)
+static void init_kvm_softmmu(struct kvm_vcpu *vcpu,
+ const struct kvm_mmu_role_regs *regs)
{
struct kvm_mmu *context = &vcpu->arch.root_mmu;
- struct kvm_mmu_role_regs regs = vcpu_to_role_regs(vcpu);

- kvm_init_shadow_mmu(vcpu, &regs);
+ kvm_init_shadow_mmu(vcpu, regs);

context->get_guest_pgd = kvm_get_guest_cr3;
context->get_pdptr = kvm_pdptr_read;
@@ -4970,10 +4970,9 @@ kvm_calc_nested_mmu_role(struct kvm_vcpu *vcpu, const struct kvm_mmu_role_regs *
return role;
}

-static void init_kvm_nested_mmu(struct kvm_vcpu *vcpu)
+static void init_kvm_nested_mmu(struct kvm_vcpu *vcpu, const struct kvm_mmu_role_regs *regs)
{
- struct kvm_mmu_role_regs regs = vcpu_to_role_regs(vcpu);
- union kvm_mmu_role new_role = kvm_calc_nested_mmu_role(vcpu, &regs);
+ union kvm_mmu_role new_role = kvm_calc_nested_mmu_role(vcpu, regs);
struct kvm_mmu *g_context = &vcpu->arch.nested_mmu;

if (new_role.as_u64 == g_context->mmu_role.as_u64)
@@ -5013,12 +5012,14 @@ static void init_kvm_nested_mmu(struct kvm_vcpu *vcpu)

void kvm_init_mmu(struct kvm_vcpu *vcpu)
{
+ struct kvm_mmu_role_regs regs = vcpu_to_role_regs(vcpu);
+
if (mmu_is_nested(vcpu))
- init_kvm_nested_mmu(vcpu);
+ init_kvm_nested_mmu(vcpu, &regs);
else if (tdp_enabled)
- init_kvm_tdp_mmu(vcpu);
+ init_kvm_tdp_mmu(vcpu, &regs);
else
- init_kvm_softmmu(vcpu);
+ init_kvm_softmmu(vcpu, &regs);
}
EXPORT_SYMBOL_GPL(kvm_init_mmu);

--
2.31.1