From 155a97a3d7c78b46cef6f1a973c831bc5a4f82bb Mon Sep 17 00:00:00 2001 From: Nadav Har'El Date: Mon, 5 Aug 2013 11:07:16 +0300 Subject: [PATCH] nEPT: MMU context for nested EPT KVM's existing shadow MMU code already supports nested TDP. To use it, we need to set up a new "MMU context" for nested EPT, and create a few callbacks for it (nested_ept_*()). This context should also use the EPT versions of the page table access functions (defined in the previous patch). Then, we need to switch back and forth between this nested context and the regular MMU context when switching between L1 and L2 (when L1 runs this L2 with EPT). Reviewed-by: Xiao Guangrong Signed-off-by: Nadav Har'El Signed-off-by: Jun Nakajima Signed-off-by: Xinhao Xu Signed-off-by: Yang Zhang Signed-off-by: Gleb Natapov Signed-off-by: Paolo Bonzini --- arch/x86/kvm/mmu.c | 27 +++++++++++++++++++++++++++ arch/x86/kvm/mmu.h | 2 ++ arch/x86/kvm/vmx.c | 41 ++++++++++++++++++++++++++++++++++++++++- 3 files changed, 69 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index a215c41b5176..992fde984e25 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -3795,6 +3795,33 @@ int kvm_init_shadow_mmu(struct kvm_vcpu *vcpu, struct kvm_mmu *context) } EXPORT_SYMBOL_GPL(kvm_init_shadow_mmu); +int kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, struct kvm_mmu *context, + bool execonly) +{ + ASSERT(vcpu); + ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa)); + + context->shadow_root_level = kvm_x86_ops->get_tdp_level(); + + context->nx = true; + context->new_cr3 = paging_new_cr3; + context->page_fault = ept_page_fault; + context->gva_to_gpa = ept_gva_to_gpa; + context->sync_page = ept_sync_page; + context->invlpg = ept_invlpg; + context->update_pte = ept_update_pte; + context->free = paging_free; + context->root_level = context->shadow_root_level; + context->root_hpa = INVALID_PAGE; + context->direct_map = false; + + update_permission_bitmask(vcpu, context, true); + reset_rsvds_bits_mask_ept(vcpu, context, execonly); + + return 0; +} +EXPORT_SYMBOL_GPL(kvm_init_shadow_ept_mmu); + static int init_kvm_softmmu(struct kvm_vcpu *vcpu) { int r = kvm_init_shadow_mmu(vcpu, vcpu->arch.walk_mmu); diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h index 5b59c573aba7..77e044a0f5f7 100644 --- a/arch/x86/kvm/mmu.h +++ b/arch/x86/kvm/mmu.h @@ -71,6 +71,8 @@ enum { int handle_mmio_page_fault_common(struct kvm_vcpu *vcpu, u64 addr, bool direct); int kvm_init_shadow_mmu(struct kvm_vcpu *vcpu, struct kvm_mmu *context); +int kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, struct kvm_mmu *context, + bool execonly); static inline unsigned int kvm_mmu_available_pages(struct kvm *kvm) { diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 0d18ed31671c..2ae0aa4461e8 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -1046,6 +1046,11 @@ static inline bool nested_cpu_has_virtual_nmis(struct vmcs12 *vmcs12, return vmcs12->pin_based_vm_exec_control & PIN_BASED_VIRTUAL_NMIS; } +static inline int nested_cpu_has_ept(struct vmcs12 *vmcs12) +{ + return nested_cpu_has2(vmcs12, SECONDARY_EXEC_ENABLE_EPT); +} + static inline bool is_exception(u32 intr_info) { return (intr_info & (INTR_INFO_INTR_TYPE_MASK | INTR_INFO_VALID_MASK)) @@ -7367,6 +7372,33 @@ static void nested_ept_inject_page_fault(struct kvm_vcpu *vcpu, vmcs12->guest_physical_address = fault->address; } +/* Callbacks for nested_ept_init_mmu_context: */ + +static unsigned long nested_ept_get_cr3(struct kvm_vcpu *vcpu) +{ + /* return the page table to be shadowed - in our case, EPT12 */ + return get_vmcs12(vcpu)->ept_pointer; +} + +static int nested_ept_init_mmu_context(struct kvm_vcpu *vcpu) +{ + int r = kvm_init_shadow_ept_mmu(vcpu, &vcpu->arch.mmu, + nested_vmx_ept_caps & VMX_EPT_EXECUTE_ONLY_BIT); + + vcpu->arch.mmu.set_cr3 = vmx_set_cr3; + vcpu->arch.mmu.get_cr3 = nested_ept_get_cr3; + vcpu->arch.mmu.inject_page_fault = nested_ept_inject_page_fault; + + vcpu->arch.walk_mmu = &vcpu->arch.nested_mmu; + + return r; +} + +static void nested_ept_uninit_mmu_context(struct kvm_vcpu *vcpu) +{ + vcpu->arch.walk_mmu = &vcpu->arch.mmu; +} + /* * prepare_vmcs02 is called when the L1 guest hypervisor runs its nested * L2 guest. L1 has a vmcs for L2 (vmcs12), and this function "merges" it @@ -7587,6 +7619,11 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) vmx_flush_tlb(vcpu); } + if (nested_cpu_has_ept(vmcs12)) { + kvm_mmu_unload(vcpu); + nested_ept_init_mmu_context(vcpu); + } + if (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_EFER) vcpu->arch.efer = vmcs12->guest_ia32_efer; else if (vmcs12->vm_entry_controls & VM_ENTRY_IA32E_MODE) @@ -8059,7 +8096,9 @@ static void load_vmcs12_host_state(struct kvm_vcpu *vcpu, vcpu->arch.cr4_guest_owned_bits = ~vmcs_readl(CR4_GUEST_HOST_MASK); kvm_set_cr4(vcpu, vmcs12->host_cr4); - /* shadow page tables on either EPT or shadow page tables */ + if (nested_cpu_has_ept(vmcs12)) + nested_ept_uninit_mmu_context(vcpu); + kvm_set_cr3(vcpu, vmcs12->host_cr3); kvm_mmu_reset_context(vcpu);