KVM: nVMX: Emulate EPTP switching for the L1 hypervisor
When L2 uses vmfunc, L0 utilizes the associated vmexit to emulate a switching of the ept pointer by reloading the guest MMU. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Bandan Das <bsd@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
This commit is contained in:
Bandan Das
Paolo Bonzini
Родитель
27c42a1bb8
Коммит
41ab937274
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@ -115,6 +115,10 @@
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#define VMX_MISC_SAVE_EFER_LMA 0x00000020
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#define VMX_MISC_ACTIVITY_HLT 0x00000040
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/* VMFUNC functions */
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#define VMX_VMFUNC_EPTP_SWITCHING 0x00000001
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#define VMFUNC_EPTP_ENTRIES 512
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static inline u32 vmx_basic_vmcs_revision_id(u64 vmx_basic)
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{
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return vmx_basic & GENMASK_ULL(30, 0);
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@ -200,6 +204,8 @@ enum vmcs_field {
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EOI_EXIT_BITMAP2_HIGH = 0x00002021,
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EOI_EXIT_BITMAP3 = 0x00002022,
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EOI_EXIT_BITMAP3_HIGH = 0x00002023,
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EPTP_LIST_ADDRESS = 0x00002024,
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EPTP_LIST_ADDRESS_HIGH = 0x00002025,
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VMREAD_BITMAP = 0x00002026,
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VMWRITE_BITMAP = 0x00002028,
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XSS_EXIT_BITMAP = 0x0000202C,
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@ -249,6 +249,7 @@ struct __packed vmcs12 {
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u64 eoi_exit_bitmap1;
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u64 eoi_exit_bitmap2;
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u64 eoi_exit_bitmap3;
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u64 eptp_list_address;
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u64 xss_exit_bitmap;
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u64 guest_physical_address;
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u64 vmcs_link_pointer;
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@ -771,6 +772,7 @@ static const unsigned short vmcs_field_to_offset_table[] = {
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FIELD64(EOI_EXIT_BITMAP1, eoi_exit_bitmap1),
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FIELD64(EOI_EXIT_BITMAP2, eoi_exit_bitmap2),
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FIELD64(EOI_EXIT_BITMAP3, eoi_exit_bitmap3),
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FIELD64(EPTP_LIST_ADDRESS, eptp_list_address),
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FIELD64(XSS_EXIT_BITMAP, xss_exit_bitmap),
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FIELD64(GUEST_PHYSICAL_ADDRESS, guest_physical_address),
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FIELD64(VMCS_LINK_POINTER, vmcs_link_pointer),
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@ -1388,6 +1390,13 @@ static inline bool nested_cpu_has_vmfunc(struct vmcs12 *vmcs12)
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return nested_cpu_has2(vmcs12, SECONDARY_EXEC_ENABLE_VMFUNC);
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}
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static inline bool nested_cpu_has_eptp_switching(struct vmcs12 *vmcs12)
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{
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return nested_cpu_has_vmfunc(vmcs12) &&
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(vmcs12->vm_function_control &
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VMX_VMFUNC_EPTP_SWITCHING);
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}
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static inline bool is_nmi(u32 intr_info)
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{
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return (intr_info & (INTR_INFO_INTR_TYPE_MASK | INTR_INFO_VALID_MASK))
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@ -2839,7 +2848,12 @@ static void nested_vmx_setup_ctls_msrs(struct vcpu_vmx *vmx)
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if (cpu_has_vmx_vmfunc()) {
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vmx->nested.nested_vmx_secondary_ctls_high |=
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SECONDARY_EXEC_ENABLE_VMFUNC;
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vmx->nested.nested_vmx_vmfunc_controls = 0;
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/*
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* Advertise EPTP switching unconditionally
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* since we emulate it
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*/
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vmx->nested.nested_vmx_vmfunc_controls =
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VMX_VMFUNC_EPTP_SWITCHING;
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}
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/*
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@ -7862,6 +7876,88 @@ static int handle_preemption_timer(struct kvm_vcpu *vcpu)
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return 1;
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}
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static bool valid_ept_address(struct kvm_vcpu *vcpu, u64 address)
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{
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struct vcpu_vmx *vmx = to_vmx(vcpu);
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u64 mask = address & 0x7;
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int maxphyaddr = cpuid_maxphyaddr(vcpu);
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/* Check for memory type validity */
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switch (mask) {
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case 0:
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if (!(vmx->nested.nested_vmx_ept_caps & VMX_EPTP_UC_BIT))
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return false;
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break;
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case 6:
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if (!(vmx->nested.nested_vmx_ept_caps & VMX_EPTP_WB_BIT))
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return false;
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break;
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default:
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return false;
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}
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/* Bits 5:3 must be 3 */
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if (((address >> VMX_EPT_GAW_EPTP_SHIFT) & 0x7) != VMX_EPT_DEFAULT_GAW)
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return false;
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/* Reserved bits should not be set */
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if (address >> maxphyaddr || ((address >> 7) & 0x1f))
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return false;
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/* AD, if set, should be supported */
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if ((address & VMX_EPT_AD_ENABLE_BIT)) {
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if (!(vmx->nested.nested_vmx_ept_caps & VMX_EPT_AD_BIT))
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return false;
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}
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return true;
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}
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static int nested_vmx_eptp_switching(struct kvm_vcpu *vcpu,
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struct vmcs12 *vmcs12)
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{
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u32 index = vcpu->arch.regs[VCPU_REGS_RCX];
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u64 address;
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bool accessed_dirty;
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struct kvm_mmu *mmu = vcpu->arch.walk_mmu;
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if (!nested_cpu_has_eptp_switching(vmcs12) ||
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!nested_cpu_has_ept(vmcs12))
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return 1;
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if (index >= VMFUNC_EPTP_ENTRIES)
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return 1;
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if (kvm_vcpu_read_guest_page(vcpu, vmcs12->eptp_list_address >> PAGE_SHIFT,
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&address, index * 8, 8))
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return 1;
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accessed_dirty = !!(address & VMX_EPT_AD_ENABLE_BIT);
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/*
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* If the (L2) guest does a vmfunc to the currently
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* active ept pointer, we don't have to do anything else
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*/
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if (vmcs12->ept_pointer != address) {
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if (!valid_ept_address(vcpu, address))
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return 1;
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kvm_mmu_unload(vcpu);
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mmu->ept_ad = accessed_dirty;
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mmu->base_role.ad_disabled = !accessed_dirty;
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vmcs12->ept_pointer = address;
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/*
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* TODO: Check what's the correct approach in case
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* mmu reload fails. Currently, we just let the next
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* reload potentially fail
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*/
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kvm_mmu_reload(vcpu);
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}
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return 0;
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}
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static int handle_vmfunc(struct kvm_vcpu *vcpu)
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{
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struct vcpu_vmx *vmx = to_vmx(vcpu);
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@ -7881,7 +7977,16 @@ static int handle_vmfunc(struct kvm_vcpu *vcpu)
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vmcs12 = get_vmcs12(vcpu);
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if ((vmcs12->vm_function_control & (1 << function)) == 0)
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goto fail;
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WARN_ONCE(1, "VMCS12 VM function control should have been zero");
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switch (function) {
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case 0:
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if (nested_vmx_eptp_switching(vcpu, vmcs12))
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goto fail;
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break;
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default:
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goto fail;
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}
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return kvm_skip_emulated_instruction(vcpu);
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fail:
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nested_vmx_vmexit(vcpu, vmx->exit_reason,
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@ -10524,10 +10629,17 @@ static int check_vmentry_prereqs(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
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vmx->nested.nested_vmx_entry_ctls_high))
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return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
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if (nested_cpu_has_vmfunc(vmcs12) &&
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(vmcs12->vm_function_control &
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~vmx->nested.nested_vmx_vmfunc_controls))
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return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
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if (nested_cpu_has_vmfunc(vmcs12)) {
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if (vmcs12->vm_function_control &
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~vmx->nested.nested_vmx_vmfunc_controls)
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return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
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if (nested_cpu_has_eptp_switching(vmcs12)) {
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if (!nested_cpu_has_ept(vmcs12) ||
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!page_address_valid(vcpu, vmcs12->eptp_list_address))
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return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
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}
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}
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if (vmcs12->cr3_target_count > nested_cpu_vmx_misc_cr3_count(vcpu))
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return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
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