[PATCH 08/24] KVM: x86/mmu: move get_guest_pgd to struct kvm_pagewalk
From: Paolo Bonzini
Date: Wed Jun 03 2026 - 07:19:35 EST
Start moving page walking functionality out of kvm_mmu. The easiest
target is the callbacks; change the kvm_mmu_get_guest_pgd() wrapper
to take a struct kvm_pagewalk too, and avoid the MMU indirection
whenever the caller has one.
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
arch/x86/include/asm/kvm_host.h | 2 +-
arch/x86/kvm/mmu/mmu.c | 21 ++++++++++++---------
arch/x86/kvm/mmu/paging_tmpl.h | 2 +-
arch/x86/kvm/svm/nested.c | 4 +++-
arch/x86/kvm/vmx/nested.c | 3 ++-
5 files changed, 19 insertions(+), 13 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index f72af337330b..81c0ae3fc3f3 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -480,12 +480,12 @@ struct kvm_page_fault;
* current mmu mode.
*/
struct kvm_pagewalk {
+ unsigned long (*get_guest_pgd)(struct kvm_vcpu *vcpu);
};
struct kvm_mmu {
struct kvm_pagewalk w;
- unsigned long (*get_guest_pgd)(struct kvm_vcpu *vcpu);
u64 (*get_pdptr)(struct kvm_vcpu *vcpu, int index);
int (*page_fault)(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault);
void (*inject_page_fault)(struct kvm_vcpu *vcpu,
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 42b7397a1845..8981e5526ba1 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -269,12 +269,12 @@ static unsigned long get_guest_cr3(struct kvm_vcpu *vcpu)
}
static inline unsigned long kvm_mmu_get_guest_pgd(struct kvm_vcpu *vcpu,
- struct kvm_mmu *mmu)
+ struct kvm_pagewalk *w)
{
- if (IS_ENABLED(CONFIG_MITIGATION_RETPOLINE) && mmu->get_guest_pgd == get_guest_cr3)
+ if (IS_ENABLED(CONFIG_MITIGATION_RETPOLINE) && w->get_guest_pgd == get_guest_cr3)
return kvm_read_cr3(vcpu);
- return mmu->get_guest_pgd(vcpu);
+ return w->get_guest_pgd(vcpu);
}
static inline bool kvm_available_flush_remote_tlbs_range(void)
@@ -4071,7 +4071,7 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu)
int quadrant, i, r;
hpa_t root;
- root_pgd = kvm_mmu_get_guest_pgd(vcpu, mmu);
+ root_pgd = kvm_mmu_get_guest_pgd(vcpu, &mmu->w);
root_gfn = (root_pgd & __PT_BASE_ADDR_MASK) >> PAGE_SHIFT;
if (!kvm_vcpu_is_visible_gfn(vcpu, root_gfn)) {
@@ -4543,7 +4543,7 @@ static bool kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu,
if (arch.direct_map)
arch.cr3 = (unsigned long)INVALID_GPA;
else
- arch.cr3 = kvm_mmu_get_guest_pgd(vcpu, vcpu->arch.mmu);
+ arch.cr3 = kvm_mmu_get_guest_pgd(vcpu, &vcpu->arch.mmu->w);
return kvm_setup_async_pf(vcpu, fault->addr,
kvm_vcpu_gfn_to_hva(vcpu, fault->gfn), &arch);
@@ -4565,7 +4565,7 @@ void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf *work)
return;
if (!vcpu->arch.mmu->root_role.direct &&
- work->arch.cr3 != kvm_mmu_get_guest_pgd(vcpu, vcpu->arch.mmu))
+ work->arch.cr3 != kvm_mmu_get_guest_pgd(vcpu, &vcpu->arch.mmu->w))
return;
r = kvm_mmu_do_page_fault(vcpu, work->cr2_or_gpa, work->arch.error_code,
@@ -5880,10 +5880,11 @@ static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu,
context->root_role.word = root_role.word;
context->page_fault = kvm_tdp_page_fault;
context->sync_spte = NULL;
- context->get_guest_pgd = get_guest_cr3;
context->get_pdptr = kvm_pdptr_read;
context->inject_page_fault = kvm_inject_page_fault;
+ context->w.get_guest_pgd = get_guest_cr3;
+
if (!is_cr0_pg(context))
context->gva_to_gpa = nonpaging_gva_to_gpa;
else if (is_cr4_pae(context))
@@ -6031,7 +6032,8 @@ static void init_kvm_softmmu(struct kvm_vcpu *vcpu,
kvm_init_shadow_mmu(vcpu, cpu_role);
- context->get_guest_pgd = get_guest_cr3;
+ context->w.get_guest_pgd = get_guest_cr3;
+
context->get_pdptr = kvm_pdptr_read;
context->inject_page_fault = kvm_inject_page_fault;
}
@@ -6045,10 +6047,11 @@ static void init_kvm_nested_mmu(struct kvm_vcpu *vcpu,
return;
g_context->cpu_role.as_u64 = new_mode.as_u64;
- g_context->get_guest_pgd = get_guest_cr3;
g_context->get_pdptr = kvm_pdptr_read;
g_context->inject_page_fault = kvm_inject_page_fault;
+ g_context->w.get_guest_pgd = get_guest_cr3;
+
/*
* L2 page tables are never shadowed, so there is no need to sync
* SPTEs.
diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h
index ab1aebf2f73c..9c3ccea6cd6b 100644
--- a/arch/x86/kvm/mmu/paging_tmpl.h
+++ b/arch/x86/kvm/mmu/paging_tmpl.h
@@ -342,7 +342,7 @@ static int FNAME(walk_addr_generic)(struct guest_walker *walker,
trace_kvm_mmu_pagetable_walk(addr, access);
retry_walk:
walker->level = mmu->cpu_role.base.level;
- pte = kvm_mmu_get_guest_pgd(vcpu, mmu);
+ pte = kvm_mmu_get_guest_pgd(vcpu, w);
have_ad = PT_HAVE_ACCESSED_DIRTY(mmu);
#if PTTYPE == 64
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index aa5a1d8ea136..9f491f45eeb6 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -97,7 +97,9 @@ static void nested_svm_init_mmu_context(struct kvm_vcpu *vcpu)
svm->vmcb01.ptr->save.efer,
svm->nested.ctl.nested_cr3,
svm->nested.ctl.misc_ctl);
- vcpu->arch.mmu->get_guest_pgd = nested_svm_get_tdp_cr3;
+
+ vcpu->arch.mmu->w.get_guest_pgd = nested_svm_get_tdp_cr3;
+
vcpu->arch.mmu->get_pdptr = nested_svm_get_tdp_pdptr;
vcpu->arch.mmu->inject_page_fault = nested_svm_inject_npf_exit;
vcpu->arch.walk_mmu = &vcpu->arch.nested_mmu;
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 1bd0839146fd..db63ae44c988 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -494,7 +494,8 @@ static void nested_ept_init_mmu_context(struct kvm_vcpu *vcpu)
vcpu->arch.mmu = &vcpu->arch.guest_mmu;
nested_ept_new_eptp(vcpu);
- vcpu->arch.mmu->get_guest_pgd = nested_ept_get_eptp;
+ vcpu->arch.mmu->w.get_guest_pgd = nested_ept_get_eptp;
+
vcpu->arch.mmu->inject_page_fault = nested_ept_inject_page_fault;
vcpu->arch.mmu->get_pdptr = kvm_pdptr_read;
--
2.52.0