[PATCH 05/23] KVM: MMU: pull computation of kvm_mmu_role_regs to kvm_init_mmu

Paolo Bonzini
2022-02-04T11:57:53Z

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.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/kvm/mmu/mmu.c | 33 +++++++++++++++++----------------
1 file changed, 17 insertions(+), 16 deletions(-)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 3add9d8b0630..577e70509510 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -4736,12 +4736,12 @@ 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;
@@ -4755,7 +4755,7 @@ static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu)
context->get_guest_pgd = get_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;
@@ -4803,7 +4803,7 @@ kvm_calc_shadow_mmu_root_page_role(struct kvm_vcpu *vcpu,
}

static void shadow_mmu_init_context(struct kvm_vcpu *vcpu, struct kvm_mmu *context,
- struct kvm_mmu_role_regs *regs,
+ const struct kvm_mmu_role_regs *regs,
union kvm_mmu_role new_role)
{
if (new_role.as_u64 == context->mmu_role.as_u64)
@@ -4824,7 +4824,7 @@ static void shadow_mmu_init_context(struct kvm_vcpu *vcpu, struct kvm_mmu *conte
}

static void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu,
- struct kvm_mmu_role_regs *regs)
+ const struct kvm_mmu_role_regs *regs)
{
struct kvm_mmu *context = &vcpu->arch.root_mmu;
union kvm_mmu_role new_role =
@@ -4845,7 +4845,7 @@ static void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu,

static union kvm_mmu_role
kvm_calc_shadow_npt_root_page_role(struct kvm_vcpu *vcpu,
- struct kvm_mmu_role_regs *regs)
+ const struct kvm_mmu_role_regs *regs)
{
union kvm_mmu_role role =
kvm_calc_shadow_root_page_role_common(vcpu, regs, false);
@@ -4930,12 +4930,12 @@ 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 = get_cr3;
context->get_pdptr = kvm_pdptr_read;
@@ -4959,10 +4959,9 @@ 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)
@@ -5002,12 +5001,14 @@ 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