[PATCH 19/22] KVM: MMU: Introduce init_kvm_nested_mmu()

Joerg Roedel
2010-04-27T10:38:29Z

This patch introduces the init_kvm_nested_mmu() function
which is used to re-initialize the nested mmu when the l2
guest changes its paging mode.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
---
arch/x86/kvm/mmu.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 54 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 8bd40b5..af89e71 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2136,6 +2136,25 @@ static gpa_t translate_gpa(struct kvm_vcpu *vcpu, gpa_t gpa, u32 *error)
return gpa;
}

+static gpa_t translate_nested_gpa(struct kvm_vcpu *vcpu, gpa_t gpa, u32 *error)
+{
+ gpa_t t_gpa;
+ u32 access;
+ u32 err;
+
+ BUG_ON(!vcpu->arch.mmu.nested);
+
+ /* NPT walks are treated as user writes */
+ access = PFERR_WRITE_MASK | PFERR_USER_MASK;
+ t_gpa = vcpu->arch.nested_mmu.gva_to_gpa(vcpu, gpa, access, &err);
+ if (t_gpa == UNMAPPED_GVA) {
+ vcpu->arch.fault_address = gpa;
+ vcpu->arch.fault_error_code = err | PFERR_NESTED_MASK;
+ }
+
+ return t_gpa;
+}
+
static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr,
u32 access, u32 *error)
{
@@ -2465,11 +2484,45 @@ static int init_kvm_softmmu(struct kvm_vcpu *vcpu)
return r;
}

+static int init_kvm_nested_mmu(struct kvm_vcpu *vcpu)
+{
+ struct kvm_mmu *g_context = &vcpu->arch.nested_mmu;
+ struct kvm_mmu *h_context = &vcpu->arch.mmu;
+
+ g_context->get_cr3 = get_cr3;
+ g_context->translate_gpa = translate_nested_gpa;
+ g_context->inject_page_fault = kvm_inject_page_fault;
+
+ /*
+ * Note that arch.mmu.gva_to_gpa translates l2_gva to l1_gpa. The
+ * translation of l2_gpa to l1_gpa addresses is done using the
+ * arch.nested_mmu.gva_to_gpa function. Basically the gva_to_gpa
+ * functions between mmu and nested_mmu are swapped.
+ */
+ if (!is_paging(vcpu)) {
+ g_context->root_level = 0;
+ h_context->gva_to_gpa = nonpaging_gva_to_gpa_nested;
+ } else if (is_long_mode(vcpu)) {
+ g_context->root_level = PT64_ROOT_LEVEL;
+ h_context->gva_to_gpa = paging64_gva_to_gpa_nested;
+ } else if (is_pae(vcpu)) {
+ g_context->root_level = PT32E_ROOT_LEVEL;
+ h_context->gva_to_gpa = paging64_gva_to_gpa_nested;
+ } else {
+ g_context->root_level = PT32_ROOT_LEVEL;
+ h_context->gva_to_gpa = paging32_gva_to_gpa_nested;
+ }
+
+ return 0;
+}
+
static int init_kvm_mmu(struct kvm_vcpu *vcpu)
{
vcpu->arch.update_pte.pfn = bad_pfn;

- if (tdp_enabled)
+ if (vcpu->arch.mmu.nested)
+ return init_kvm_nested_mmu(vcpu);
+ else if (tdp_enabled)
return init_kvm_tdp_mmu(vcpu);
else
return init_kvm_softmmu(vcpu);
--
1.7.0.4