KVM: nVMX: Prepare vmcs02 from vmcs01 and vmcs12
This patch contains code to prepare the VMCS which can be used to actually run the L2 guest, vmcs02. prepare_vmcs02 appropriately merges the information in vmcs12 (the vmcs that L1 built for L2) and in vmcs01 (our desires for our own guests). Signed-off-by: Nadav Har'El <nyh@il.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This commit is contained in:
Nadav Har'El
Avi Kivity
Родитель
bf8179a011
Коммит
fe3ef05c75
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@ -345,6 +345,12 @@ struct nested_vmx {
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/* vmcs02_list cache of VMCSs recently used to run L2 guests */
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struct list_head vmcs02_pool;
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int vmcs02_num;
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u64 vmcs01_tsc_offset;
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/*
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* Guest pages referred to in vmcs02 with host-physical pointers, so
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* we must keep them pinned while L2 runs.
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*/
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struct page *apic_access_page;
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};
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struct vcpu_vmx {
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@ -847,6 +853,18 @@ static inline bool report_flexpriority(void)
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return flexpriority_enabled;
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}
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static inline bool nested_cpu_has(struct vmcs12 *vmcs12, u32 bit)
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{
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return vmcs12->cpu_based_vm_exec_control & bit;
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}
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static inline bool nested_cpu_has2(struct vmcs12 *vmcs12, u32 bit)
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{
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return (vmcs12->cpu_based_vm_exec_control &
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CPU_BASED_ACTIVATE_SECONDARY_CONTROLS) &&
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(vmcs12->secondary_vm_exec_control & bit);
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}
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static int __find_msr_index(struct vcpu_vmx *vmx, u32 msr)
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{
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int i;
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@ -1441,6 +1459,22 @@ static void vmx_fpu_activate(struct kvm_vcpu *vcpu)
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static void vmx_decache_cr0_guest_bits(struct kvm_vcpu *vcpu);
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/*
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* Return the cr0 value that a nested guest would read. This is a combination
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* of the real cr0 used to run the guest (guest_cr0), and the bits shadowed by
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* its hypervisor (cr0_read_shadow).
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*/
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static inline unsigned long nested_read_cr0(struct vmcs12 *fields)
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{
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return (fields->guest_cr0 & ~fields->cr0_guest_host_mask) |
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(fields->cr0_read_shadow & fields->cr0_guest_host_mask);
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}
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static inline unsigned long nested_read_cr4(struct vmcs12 *fields)
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{
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return (fields->guest_cr4 & ~fields->cr4_guest_host_mask) |
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(fields->cr4_read_shadow & fields->cr4_guest_host_mask);
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}
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static void vmx_fpu_deactivate(struct kvm_vcpu *vcpu)
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{
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vmx_decache_cr0_guest_bits(vcpu);
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@ -3438,6 +3472,9 @@ static void set_cr4_guest_host_mask(struct vcpu_vmx *vmx)
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vmx->vcpu.arch.cr4_guest_owned_bits = KVM_CR4_GUEST_OWNED_BITS;
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if (enable_ept)
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vmx->vcpu.arch.cr4_guest_owned_bits |= X86_CR4_PGE;
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if (is_guest_mode(&vmx->vcpu))
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vmx->vcpu.arch.cr4_guest_owned_bits &=
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~get_vmcs12(&vmx->vcpu)->cr4_guest_host_mask;
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vmcs_writel(CR4_GUEST_HOST_MASK, ~vmx->vcpu.arch.cr4_guest_owned_bits);
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}
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@ -4736,6 +4773,11 @@ static void free_nested(struct vcpu_vmx *vmx)
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vmx->nested.current_vmptr = -1ull;
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vmx->nested.current_vmcs12 = NULL;
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}
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/* Unpin physical memory we referred to in current vmcs02 */
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if (vmx->nested.apic_access_page) {
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nested_release_page(vmx->nested.apic_access_page);
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vmx->nested.apic_access_page = 0;
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}
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nested_free_all_saved_vmcss(vmx);
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}
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@ -5810,6 +5852,243 @@ static void vmx_set_supported_cpuid(u32 func, struct kvm_cpuid_entry2 *entry)
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{
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}
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/*
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* prepare_vmcs02 is called when the L1 guest hypervisor runs its nested
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* L2 guest. L1 has a vmcs for L2 (vmcs12), and this function "merges" it
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* with L0's requirements for its guest (a.k.a. vmsc01), so we can run the L2
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* guest in a way that will both be appropriate to L1's requests, and our
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* needs. In addition to modifying the active vmcs (which is vmcs02), this
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* function also has additional necessary side-effects, like setting various
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* vcpu->arch fields.
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*/
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static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
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{
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struct vcpu_vmx *vmx = to_vmx(vcpu);
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u32 exec_control;
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vmcs_write16(GUEST_ES_SELECTOR, vmcs12->guest_es_selector);
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vmcs_write16(GUEST_CS_SELECTOR, vmcs12->guest_cs_selector);
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vmcs_write16(GUEST_SS_SELECTOR, vmcs12->guest_ss_selector);
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vmcs_write16(GUEST_DS_SELECTOR, vmcs12->guest_ds_selector);
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vmcs_write16(GUEST_FS_SELECTOR, vmcs12->guest_fs_selector);
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vmcs_write16(GUEST_GS_SELECTOR, vmcs12->guest_gs_selector);
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vmcs_write16(GUEST_LDTR_SELECTOR, vmcs12->guest_ldtr_selector);
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vmcs_write16(GUEST_TR_SELECTOR, vmcs12->guest_tr_selector);
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vmcs_write32(GUEST_ES_LIMIT, vmcs12->guest_es_limit);
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vmcs_write32(GUEST_CS_LIMIT, vmcs12->guest_cs_limit);
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vmcs_write32(GUEST_SS_LIMIT, vmcs12->guest_ss_limit);
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vmcs_write32(GUEST_DS_LIMIT, vmcs12->guest_ds_limit);
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vmcs_write32(GUEST_FS_LIMIT, vmcs12->guest_fs_limit);
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vmcs_write32(GUEST_GS_LIMIT, vmcs12->guest_gs_limit);
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vmcs_write32(GUEST_LDTR_LIMIT, vmcs12->guest_ldtr_limit);
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vmcs_write32(GUEST_TR_LIMIT, vmcs12->guest_tr_limit);
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vmcs_write32(GUEST_GDTR_LIMIT, vmcs12->guest_gdtr_limit);
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vmcs_write32(GUEST_IDTR_LIMIT, vmcs12->guest_idtr_limit);
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vmcs_write32(GUEST_ES_AR_BYTES, vmcs12->guest_es_ar_bytes);
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vmcs_write32(GUEST_CS_AR_BYTES, vmcs12->guest_cs_ar_bytes);
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vmcs_write32(GUEST_SS_AR_BYTES, vmcs12->guest_ss_ar_bytes);
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vmcs_write32(GUEST_DS_AR_BYTES, vmcs12->guest_ds_ar_bytes);
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vmcs_write32(GUEST_FS_AR_BYTES, vmcs12->guest_fs_ar_bytes);
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vmcs_write32(GUEST_GS_AR_BYTES, vmcs12->guest_gs_ar_bytes);
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vmcs_write32(GUEST_LDTR_AR_BYTES, vmcs12->guest_ldtr_ar_bytes);
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vmcs_write32(GUEST_TR_AR_BYTES, vmcs12->guest_tr_ar_bytes);
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vmcs_writel(GUEST_ES_BASE, vmcs12->guest_es_base);
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vmcs_writel(GUEST_CS_BASE, vmcs12->guest_cs_base);
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vmcs_writel(GUEST_SS_BASE, vmcs12->guest_ss_base);
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vmcs_writel(GUEST_DS_BASE, vmcs12->guest_ds_base);
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vmcs_writel(GUEST_FS_BASE, vmcs12->guest_fs_base);
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vmcs_writel(GUEST_GS_BASE, vmcs12->guest_gs_base);
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vmcs_writel(GUEST_LDTR_BASE, vmcs12->guest_ldtr_base);
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vmcs_writel(GUEST_TR_BASE, vmcs12->guest_tr_base);
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vmcs_writel(GUEST_GDTR_BASE, vmcs12->guest_gdtr_base);
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vmcs_writel(GUEST_IDTR_BASE, vmcs12->guest_idtr_base);
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vmcs_write64(GUEST_IA32_DEBUGCTL, vmcs12->guest_ia32_debugctl);
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vmcs_write32(VM_ENTRY_INTR_INFO_FIELD,
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vmcs12->vm_entry_intr_info_field);
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vmcs_write32(VM_ENTRY_EXCEPTION_ERROR_CODE,
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vmcs12->vm_entry_exception_error_code);
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vmcs_write32(VM_ENTRY_INSTRUCTION_LEN,
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vmcs12->vm_entry_instruction_len);
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vmcs_write32(GUEST_INTERRUPTIBILITY_INFO,
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vmcs12->guest_interruptibility_info);
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vmcs_write32(GUEST_ACTIVITY_STATE, vmcs12->guest_activity_state);
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vmcs_write32(GUEST_SYSENTER_CS, vmcs12->guest_sysenter_cs);
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vmcs_writel(GUEST_DR7, vmcs12->guest_dr7);
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vmcs_writel(GUEST_RFLAGS, vmcs12->guest_rflags);
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vmcs_writel(GUEST_PENDING_DBG_EXCEPTIONS,
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vmcs12->guest_pending_dbg_exceptions);
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vmcs_writel(GUEST_SYSENTER_ESP, vmcs12->guest_sysenter_esp);
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vmcs_writel(GUEST_SYSENTER_EIP, vmcs12->guest_sysenter_eip);
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vmcs_write64(VMCS_LINK_POINTER, -1ull);
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vmcs_write32(PIN_BASED_VM_EXEC_CONTROL,
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(vmcs_config.pin_based_exec_ctrl |
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vmcs12->pin_based_vm_exec_control));
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/*
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* Whether page-faults are trapped is determined by a combination of
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* 3 settings: PFEC_MASK, PFEC_MATCH and EXCEPTION_BITMAP.PF.
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* If enable_ept, L0 doesn't care about page faults and we should
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* set all of these to L1's desires. However, if !enable_ept, L0 does
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* care about (at least some) page faults, and because it is not easy
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* (if at all possible?) to merge L0 and L1's desires, we simply ask
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* to exit on each and every L2 page fault. This is done by setting
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* MASK=MATCH=0 and (see below) EB.PF=1.
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* Note that below we don't need special code to set EB.PF beyond the
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* "or"ing of the EB of vmcs01 and vmcs12, because when enable_ept,
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* vmcs01's EB.PF is 0 so the "or" will take vmcs12's value, and when
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* !enable_ept, EB.PF is 1, so the "or" will always be 1.
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*
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* A problem with this approach (when !enable_ept) is that L1 may be
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* injected with more page faults than it asked for. This could have
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* caused problems, but in practice existing hypervisors don't care.
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* To fix this, we will need to emulate the PFEC checking (on the L1
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* page tables), using walk_addr(), when injecting PFs to L1.
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*/
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vmcs_write32(PAGE_FAULT_ERROR_CODE_MASK,
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enable_ept ? vmcs12->page_fault_error_code_mask : 0);
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vmcs_write32(PAGE_FAULT_ERROR_CODE_MATCH,
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enable_ept ? vmcs12->page_fault_error_code_match : 0);
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if (cpu_has_secondary_exec_ctrls()) {
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u32 exec_control = vmx_secondary_exec_control(vmx);
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if (!vmx->rdtscp_enabled)
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exec_control &= ~SECONDARY_EXEC_RDTSCP;
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/* Take the following fields only from vmcs12 */
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exec_control &= ~SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES;
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if (nested_cpu_has(vmcs12,
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CPU_BASED_ACTIVATE_SECONDARY_CONTROLS))
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exec_control |= vmcs12->secondary_vm_exec_control;
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if (exec_control & SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES) {
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/*
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* Translate L1 physical address to host physical
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* address for vmcs02. Keep the page pinned, so this
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* physical address remains valid. We keep a reference
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* to it so we can release it later.
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*/
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if (vmx->nested.apic_access_page) /* shouldn't happen */
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nested_release_page(vmx->nested.apic_access_page);
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vmx->nested.apic_access_page =
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nested_get_page(vcpu, vmcs12->apic_access_addr);
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/*
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* If translation failed, no matter: This feature asks
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* to exit when accessing the given address, and if it
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* can never be accessed, this feature won't do
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* anything anyway.
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*/
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if (!vmx->nested.apic_access_page)
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exec_control &=
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~SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES;
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else
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vmcs_write64(APIC_ACCESS_ADDR,
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page_to_phys(vmx->nested.apic_access_page));
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}
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vmcs_write32(SECONDARY_VM_EXEC_CONTROL, exec_control);
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}
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/*
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* Set host-state according to L0's settings (vmcs12 is irrelevant here)
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* Some constant fields are set here by vmx_set_constant_host_state().
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* Other fields are different per CPU, and will be set later when
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* vmx_vcpu_load() is called, and when vmx_save_host_state() is called.
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*/
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vmx_set_constant_host_state();
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/*
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* HOST_RSP is normally set correctly in vmx_vcpu_run() just before
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* entry, but only if the current (host) sp changed from the value
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* we wrote last (vmx->host_rsp). This cache is no longer relevant
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* if we switch vmcs, and rather than hold a separate cache per vmcs,
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* here we just force the write to happen on entry.
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*/
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vmx->host_rsp = 0;
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exec_control = vmx_exec_control(vmx); /* L0's desires */
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exec_control &= ~CPU_BASED_VIRTUAL_INTR_PENDING;
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exec_control &= ~CPU_BASED_VIRTUAL_NMI_PENDING;
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exec_control &= ~CPU_BASED_TPR_SHADOW;
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exec_control |= vmcs12->cpu_based_vm_exec_control;
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/*
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* Merging of IO and MSR bitmaps not currently supported.
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* Rather, exit every time.
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*/
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exec_control &= ~CPU_BASED_USE_MSR_BITMAPS;
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exec_control &= ~CPU_BASED_USE_IO_BITMAPS;
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exec_control |= CPU_BASED_UNCOND_IO_EXITING;
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vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, exec_control);
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/* EXCEPTION_BITMAP and CR0_GUEST_HOST_MASK should basically be the
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* bitwise-or of what L1 wants to trap for L2, and what we want to
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* trap. Note that CR0.TS also needs updating - we do this later.
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*/
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update_exception_bitmap(vcpu);
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vcpu->arch.cr0_guest_owned_bits &= ~vmcs12->cr0_guest_host_mask;
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vmcs_writel(CR0_GUEST_HOST_MASK, ~vcpu->arch.cr0_guest_owned_bits);
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/* Note: IA32_MODE, LOAD_IA32_EFER are modified by vmx_set_efer below */
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vmcs_write32(VM_EXIT_CONTROLS,
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vmcs12->vm_exit_controls | vmcs_config.vmexit_ctrl);
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vmcs_write32(VM_ENTRY_CONTROLS, vmcs12->vm_entry_controls |
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(vmcs_config.vmentry_ctrl & ~VM_ENTRY_IA32E_MODE));
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if (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_PAT)
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vmcs_write64(GUEST_IA32_PAT, vmcs12->guest_ia32_pat);
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else if (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_PAT)
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vmcs_write64(GUEST_IA32_PAT, vmx->vcpu.arch.pat);
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set_cr4_guest_host_mask(vmx);
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vmcs_write64(TSC_OFFSET,
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vmx->nested.vmcs01_tsc_offset + vmcs12->tsc_offset);
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if (enable_vpid) {
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/*
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* Trivially support vpid by letting L2s share their parent
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* L1's vpid. TODO: move to a more elaborate solution, giving
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* each L2 its own vpid and exposing the vpid feature to L1.
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*/
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vmcs_write16(VIRTUAL_PROCESSOR_ID, vmx->vpid);
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vmx_flush_tlb(vcpu);
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}
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if (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_EFER)
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vcpu->arch.efer = vmcs12->guest_ia32_efer;
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if (vmcs12->vm_entry_controls & VM_ENTRY_IA32E_MODE)
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vcpu->arch.efer |= (EFER_LMA | EFER_LME);
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else
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vcpu->arch.efer &= ~(EFER_LMA | EFER_LME);
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/* Note: modifies VM_ENTRY/EXIT_CONTROLS and GUEST/HOST_IA32_EFER */
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vmx_set_efer(vcpu, vcpu->arch.efer);
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/*
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* This sets GUEST_CR0 to vmcs12->guest_cr0, with possibly a modified
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* TS bit (for lazy fpu) and bits which we consider mandatory enabled.
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* The CR0_READ_SHADOW is what L2 should have expected to read given
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* the specifications by L1; It's not enough to take
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* vmcs12->cr0_read_shadow because on our cr0_guest_host_mask we we
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* have more bits than L1 expected.
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*/
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vmx_set_cr0(vcpu, vmcs12->guest_cr0);
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vmcs_writel(CR0_READ_SHADOW, nested_read_cr0(vmcs12));
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vmx_set_cr4(vcpu, vmcs12->guest_cr4);
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vmcs_writel(CR4_READ_SHADOW, nested_read_cr4(vmcs12));
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/* shadow page tables on either EPT or shadow page tables */
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kvm_set_cr3(vcpu, vmcs12->guest_cr3);
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kvm_mmu_reset_context(vcpu);
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kvm_register_write(vcpu, VCPU_REGS_RSP, vmcs12->guest_rsp);
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kvm_register_write(vcpu, VCPU_REGS_RIP, vmcs12->guest_rip);
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}
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static int vmx_check_intercept(struct kvm_vcpu *vcpu,
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struct x86_instruction_info *info,
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enum x86_intercept_stage stage)
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