[PATCH 26/30] KVM: MMU: pass arbitrary CR0/CR4/EFER to kvm_init_shadow_mmu

[Paolo Bonzini]

This allows fetching the registers from the hsave area when setting
up the NPT shadow MMU, and is needed for KVM_SET_NESTED_STATE (which
runs long after the CR0, CR4 and EFER values in vcpu have been switched
to hold L2 guest state).

Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
 arch/x86/kvm/mmu.h        |  2 +-
 arch/x86/kvm/mmu/mmu.c    | 14 +++++++++-----
 arch/x86/kvm/svm/nested.c |  5 ++++-
 3 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index 048e865ad485..0ad06bfe2c2c 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -57,7 +57,7 @@ void
 reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, struct kvm_mmu *context);
 
 void kvm_init_mmu(struct kvm_vcpu *vcpu, bool reset_roots);
-void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu);
+void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu, u32 cr0, u32 cr4, u32 efer);
 void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly,
                             bool accessed_dirty, gpa_t new_eptp);
 bool kvm_can_do_async_pf(struct kvm_vcpu *vcpu);
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index fd1c9145505c..2e62a03410c7 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -4952,7 +4952,7 @@ kvm_calc_shadow_mmu_root_page_role(struct kvm_vcpu *vcpu, 
bool base_only)
        return role;
 }
 
-void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu)
+void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu, u32 cr0, u32 cr4, u32 efer)
 {
        struct kvm_mmu *context = vcpu->arch.mmu;
        union kvm_mmu_role new_role =
@@ -4961,11 +4961,11 @@ void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu)
        if (new_role.as_u64 == context->mmu_role.as_u64)
                return;
 
-       if (!is_paging(vcpu))
+       if (!(cr0 & X86_CR0_PG))
                nonpaging_init_context(vcpu, context);
-       else if (is_long_mode(vcpu))
+       else if (efer & EFER_LMA)
                paging64_init_context(vcpu, context);
-       else if (is_pae(vcpu))
+       else if (cr4 & X86_CR4_PAE)
                paging32E_init_context(vcpu, context);
        else
                paging32_init_context(vcpu, context);
@@ -5043,7 +5043,11 @@ static void init_kvm_softmmu(struct kvm_vcpu *vcpu)
 {
        struct kvm_mmu *context = vcpu->arch.mmu;
 
-       kvm_init_shadow_mmu(vcpu);
+       kvm_init_shadow_mmu(vcpu,
+                           kvm_read_cr0_bits(vcpu, X86_CR0_PG),
+                           kvm_read_cr4_bits(vcpu, X86_CR4_PAE),
+                           vcpu->arch.efer);
+
        context->get_guest_pgd     = get_cr3;
        context->get_pdptr         = kvm_pdptr_read;
        context->inject_page_fault = kvm_inject_page_fault;
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index 369eca73fe3e..c712fe577029 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -80,10 +80,13 @@ static unsigned long nested_svm_get_tdp_cr3(struct kvm_vcpu 
*vcpu)
 
 static void nested_svm_init_mmu_context(struct kvm_vcpu *vcpu)
 {
+       struct vcpu_svm *svm = to_svm(vcpu);
+       struct vmcb *hsave = svm->nested.hsave;
+
        WARN_ON(mmu_is_nested(vcpu));
 
        vcpu->arch.mmu = &vcpu->arch.guest_mmu;
-       kvm_init_shadow_mmu(vcpu);
+       kvm_init_shadow_mmu(vcpu, X86_CR0_PG, hsave->save.cr4, 
hsave->save.efer);
        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;
-- 
2.26.2