[PATCH 20/22] KVM: SVM: Initialize Nested Nested MMU context on VMRUN

Joerg Roedel
2010-04-27T10:38:59Z

This patch adds code to initialize the Nested Nested Paging
MMU context when the L1 guest executes a VMRUN instruction
and has nested paging enabled in its VMCB.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
---
arch/x86/kvm/mmu.c | 1 +
arch/x86/kvm/svm.c | 56 ++++++++++++++++++++++++++++++++++++++++++---------
2 files changed, 47 insertions(+), 10 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index af89e71..e5dc853 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2569,6 +2569,7 @@ void kvm_mmu_unload(struct kvm_vcpu *vcpu)
{
mmu_free_roots(vcpu);
}
+EXPORT_SYMBOL_GPL(kvm_mmu_unload);

static void mmu_pte_write_zap_pte(struct kvm_vcpu *vcpu,
struct kvm_mmu_page *sp,
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index e31f601..266b1d4 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -94,7 +94,6 @@ struct nested_state {

/* Nested Paging related state */
u64 nested_cr3;
-
};

#define MSRPM_OFFSETS 16
@@ -283,6 +282,15 @@ static inline void flush_guest_tlb(struct kvm_vcpu *vcpu)
force_new_asid(vcpu);
}

+static int get_npt_level(void)
+{
+#ifdef CONFIG_X86_64
+ return PT64_ROOT_LEVEL;
+#else
+ return PT32E_ROOT_LEVEL;
+#endif
+}
+
static void svm_set_efer(struct kvm_vcpu *vcpu, u64 efer)
{
if (!npt_enabled && !(efer & EFER_LMA))
@@ -1523,6 +1531,27 @@ static void nested_svm_inject_npf_exit(struct kvm_vcpu *vcpu,
nested_svm_vmexit(svm);
}

+static int nested_svm_init_mmu_context(struct kvm_vcpu *vcpu)
+{
+ int r;
+
+ r = kvm_init_shadow_mmu(vcpu, &vcpu->arch.mmu);
+
+ vcpu->arch.mmu.set_cr3 = nested_svm_set_tdp_cr3;
+ vcpu->arch.mmu.get_cr3 = nested_svm_get_tdp_cr3;
+ vcpu->arch.mmu.inject_page_fault = nested_svm_inject_npf_exit;
+ vcpu->arch.mmu.shadow_root_level = get_npt_level();
+ vcpu->arch.nested_mmu.gva_to_gpa = vcpu->arch.mmu.gva_to_gpa;
+ vcpu->arch.mmu.nested = true;
+
+ return r;
+}
+
+static void nested_svm_uninit_mmu_context(struct kvm_vcpu *vcpu)
+{
+ vcpu->arch.mmu.nested = false;
+}
+
static int nested_svm_check_permissions(struct vcpu_svm *svm)
{
if (!(svm->vcpu.arch.efer & EFER_SVME)
@@ -1889,6 +1918,8 @@ static int nested_svm_vmexit(struct vcpu_svm *svm)
kvm_clear_exception_queue(&svm->vcpu);
kvm_clear_interrupt_queue(&svm->vcpu);

+ svm->nested.nested_cr3 = 0;
+
/* Restore selected save entries */
svm->vmcb->save.es = hsave->save.es;
svm->vmcb->save.cs = hsave->save.cs;
@@ -1915,6 +1946,7 @@ static int nested_svm_vmexit(struct vcpu_svm *svm)

nested_svm_unmap(page);

+ nested_svm_uninit_mmu_context(&svm->vcpu);
kvm_mmu_reset_context(&svm->vcpu);
kvm_mmu_load(&svm->vcpu);

@@ -1968,6 +2000,13 @@ static bool nested_svm_vmrun(struct vcpu_svm *svm)
if (!nested_vmcb)
return false;

+ /* Do check if nested paging is allowed for the guest */
+ if (nested_vmcb->control.nested_ctl && !npt_enabled) {
+ nested_vmcb->control.exit_code = SVM_EXIT_ERR;
+ nested_svm_unmap(page);
+ return false;
+ }
+
trace_kvm_nested_vmrun(svm->vmcb->save.rip - 3, vmcb_gpa,
nested_vmcb->save.rip,
nested_vmcb->control.int_ctl,
@@ -2012,6 +2051,12 @@ static bool nested_svm_vmrun(struct vcpu_svm *svm)
else
svm->vcpu.arch.hflags &= ~HF_HIF_MASK;

+ if (nested_vmcb->control.nested_ctl) {
+ kvm_mmu_unload(&svm->vcpu);
+ svm->nested.nested_cr3 = nested_vmcb->control.nested_cr3;
+ nested_svm_init_mmu_context(&svm->vcpu);
+ }
+
/* Load the nested guest state */
svm->vmcb->save.es = nested_vmcb->save.es;
svm->vmcb->save.cs = nested_vmcb->save.cs;
@@ -3171,15 +3216,6 @@ static bool svm_cpu_has_accelerated_tpr(void)
return false;
}

-static int get_npt_level(void)
-{
-#ifdef CONFIG_X86_64
- return PT64_ROOT_LEVEL;
-#else
- return PT32E_ROOT_LEVEL;
-#endif
-}
-
static u64 svm_get_mt_mask(struct kvm_vcpu *vcpu, gfn_t gfn, bool is_mmio)
{
return 0;
--
1.7.0.4