[PATCH 18/54] KVM: x86/mmu: Move nested NPT reserved bit calculation into MMU proper

From: Sean Christopherson
Date: Tue Jun 22 2021 - 13:59:49 EST


Move nested NPT's invocation of reset_shadow_zero_bits_mask() into the
MMU proper and unexport said function. Aside from dropping an export,
this is a baby step toward eliminating the call entirely by fixing the
shadow_root_level confusion.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/mmu.h | 3 ---
arch/x86/kvm/mmu/mmu.c | 11 ++++++++---
arch/x86/kvm/svm/nested.c | 1 -
3 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index 4e926f4935b0..62844bacd13f 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -68,9 +68,6 @@ static __always_inline u64 rsvd_bits(int s, int e)
void kvm_mmu_set_mmio_spte_mask(u64 mmio_value, u64 mmio_mask, u64 access_mask);
void kvm_mmu_set_ept_masks(bool has_ad_bits, bool has_exec_only);

-void
-reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, struct kvm_mmu *context);
-
void kvm_init_mmu(struct kvm_vcpu *vcpu);
void kvm_init_shadow_npt_mmu(struct kvm_vcpu *vcpu, unsigned long cr0,
unsigned long cr4, u64 efer, gpa_t nested_cr3);
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 02c54426e7a2..5a46a87b23b0 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -4212,8 +4212,8 @@ static inline u64 reserved_hpa_bits(void)
* table in guest or amd nested guest, its mmu features completely
* follow the features in guest.
*/
-void
-reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, struct kvm_mmu *context)
+static void reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu,
+ struct kvm_mmu *context)
{
/*
* KVM uses NX when TDP is disabled to handle a variety of scenarios,
@@ -4247,7 +4247,6 @@ reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, struct kvm_mmu *context)
}

}
-EXPORT_SYMBOL_GPL(reset_shadow_zero_bits_mask);

static inline bool boot_cpu_is_amd(void)
{
@@ -4714,6 +4713,12 @@ void kvm_init_shadow_npt_mmu(struct kvm_vcpu *vcpu, unsigned long cr0,
*/
context->shadow_root_level = new_role.base.level;
}
+
+ /*
+ * Redo the shadow bits, the reset done by shadow_mmu_init_context()
+ * (above) may use the wrong shadow_root_level.
+ */
+ reset_shadow_zero_bits_mask(vcpu, context);
}
EXPORT_SYMBOL_GPL(kvm_init_shadow_npt_mmu);

diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index 33b2f9337e26..927e545591c3 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -110,7 +110,6 @@ static void nested_svm_init_mmu_context(struct kvm_vcpu *vcpu)
vcpu->arch.mmu->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;
- reset_shadow_zero_bits_mask(vcpu, vcpu->arch.mmu);
vcpu->arch.walk_mmu = &vcpu->arch.nested_mmu;
}

--
2.32.0.288.g62a8d224e6-goog