diff options
Diffstat (limited to 'arch/x86/kvm/vmx.c')
-rw-r--r-- | arch/x86/kvm/vmx.c | 262 |
1 files changed, 262 insertions, 0 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index f8dccb9df34b..7d778e4976ea 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -6144,6 +6144,268 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch) return 1; } +/* + * On a nested exit from L2 to L1, vmcs12.guest_cr0 might not be up-to-date + * because L2 may have changed some cr0 bits directly (CRO_GUEST_HOST_MASK). + * This function returns the new value we should put in vmcs12.guest_cr0. + * It's not enough to just return the vmcs02 GUEST_CR0. Rather, + * 1. Bits that neither L0 nor L1 trapped, were set directly by L2 and are now + * available in vmcs02 GUEST_CR0. (Note: It's enough to check that L0 + * didn't trap the bit, because if L1 did, so would L0). + * 2. Bits that L1 asked to trap (and therefore L0 also did) could not have + * been modified by L2, and L1 knows it. So just leave the old value of + * the bit from vmcs12.guest_cr0. Note that the bit from vmcs02 GUEST_CR0 + * isn't relevant, because if L0 traps this bit it can set it to anything. + * 3. Bits that L1 didn't trap, but L0 did. L1 believes the guest could have + * changed these bits, and therefore they need to be updated, but L0 + * didn't necessarily allow them to be changed in GUEST_CR0 - and rather + * put them in vmcs02 CR0_READ_SHADOW. So take these bits from there. + */ +static inline unsigned long +vmcs12_guest_cr0(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) +{ + return + /*1*/ (vmcs_readl(GUEST_CR0) & vcpu->arch.cr0_guest_owned_bits) | + /*2*/ (vmcs12->guest_cr0 & vmcs12->cr0_guest_host_mask) | + /*3*/ (vmcs_readl(CR0_READ_SHADOW) & ~(vmcs12->cr0_guest_host_mask | + vcpu->arch.cr0_guest_owned_bits)); +} + +static inline unsigned long +vmcs12_guest_cr4(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) +{ + return + /*1*/ (vmcs_readl(GUEST_CR4) & vcpu->arch.cr4_guest_owned_bits) | + /*2*/ (vmcs12->guest_cr4 & vmcs12->cr4_guest_host_mask) | + /*3*/ (vmcs_readl(CR4_READ_SHADOW) & ~(vmcs12->cr4_guest_host_mask | + vcpu->arch.cr4_guest_owned_bits)); +} + +/* + * prepare_vmcs12 is part of what we need to do when the nested L2 guest exits + * and we want to prepare to run its L1 parent. L1 keeps a vmcs for L2 (vmcs12), + * and this function updates it to reflect the changes to the guest state while + * L2 was running (and perhaps made some exits which were handled directly by L0 + * without going back to L1), and to reflect the exit reason. + * Note that we do not have to copy here all VMCS fields, just those that + * could have changed by the L2 guest or the exit - i.e., the guest-state and + * exit-information fields only. Other fields are modified by L1 with VMWRITE, + * which already writes to vmcs12 directly. + */ +void prepare_vmcs12(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) +{ + /* update guest state fields: */ + vmcs12->guest_cr0 = vmcs12_guest_cr0(vcpu, vmcs12); + vmcs12->guest_cr4 = vmcs12_guest_cr4(vcpu, vmcs12); + + kvm_get_dr(vcpu, 7, (unsigned long *)&vmcs12->guest_dr7); + vmcs12->guest_rsp = kvm_register_read(vcpu, VCPU_REGS_RSP); + vmcs12->guest_rip = kvm_register_read(vcpu, VCPU_REGS_RIP); + vmcs12->guest_rflags = vmcs_readl(GUEST_RFLAGS); + + vmcs12->guest_es_selector = vmcs_read16(GUEST_ES_SELECTOR); + vmcs12->guest_cs_selector = vmcs_read16(GUEST_CS_SELECTOR); + vmcs12->guest_ss_selector = vmcs_read16(GUEST_SS_SELECTOR); + vmcs12->guest_ds_selector = vmcs_read16(GUEST_DS_SELECTOR); + vmcs12->guest_fs_selector = vmcs_read16(GUEST_FS_SELECTOR); + vmcs12->guest_gs_selector = vmcs_read16(GUEST_GS_SELECTOR); + vmcs12->guest_ldtr_selector = vmcs_read16(GUEST_LDTR_SELECTOR); + vmcs12->guest_tr_selector = vmcs_read16(GUEST_TR_SELECTOR); + vmcs12->guest_es_limit = vmcs_read32(GUEST_ES_LIMIT); + vmcs12->guest_cs_limit = vmcs_read32(GUEST_CS_LIMIT); + vmcs12->guest_ss_limit = vmcs_read32(GUEST_SS_LIMIT); + vmcs12->guest_ds_limit = vmcs_read32(GUEST_DS_LIMIT); + vmcs12->guest_fs_limit = vmcs_read32(GUEST_FS_LIMIT); + vmcs12->guest_gs_limit = vmcs_read32(GUEST_GS_LIMIT); + vmcs12->guest_ldtr_limit = vmcs_read32(GUEST_LDTR_LIMIT); + vmcs12->guest_tr_limit = vmcs_read32(GUEST_TR_LIMIT); + vmcs12->guest_gdtr_limit = vmcs_read32(GUEST_GDTR_LIMIT); + vmcs12->guest_idtr_limit = vmcs_read32(GUEST_IDTR_LIMIT); + vmcs12->guest_es_ar_bytes = vmcs_read32(GUEST_ES_AR_BYTES); + vmcs12->guest_cs_ar_bytes = vmcs_read32(GUEST_CS_AR_BYTES); + vmcs12->guest_ss_ar_bytes = vmcs_read32(GUEST_SS_AR_BYTES); + vmcs12->guest_ds_ar_bytes = vmcs_read32(GUEST_DS_AR_BYTES); + vmcs12->guest_fs_ar_bytes = vmcs_read32(GUEST_FS_AR_BYTES); + vmcs12->guest_gs_ar_bytes = vmcs_read32(GUEST_GS_AR_BYTES); + vmcs12->guest_ldtr_ar_bytes = vmcs_read32(GUEST_LDTR_AR_BYTES); + vmcs12->guest_tr_ar_bytes = vmcs_read32(GUEST_TR_AR_BYTES); + vmcs12->guest_es_base = vmcs_readl(GUEST_ES_BASE); + vmcs12->guest_cs_base = vmcs_readl(GUEST_CS_BASE); + vmcs12->guest_ss_base = vmcs_readl(GUEST_SS_BASE); + vmcs12->guest_ds_base = vmcs_readl(GUEST_DS_BASE); + vmcs12->guest_fs_base = vmcs_readl(GUEST_FS_BASE); + vmcs12->guest_gs_base = vmcs_readl(GUEST_GS_BASE); + vmcs12->guest_ldtr_base = vmcs_readl(GUEST_LDTR_BASE); + vmcs12->guest_tr_base = vmcs_readl(GUEST_TR_BASE); + vmcs12->guest_gdtr_base = vmcs_readl(GUEST_GDTR_BASE); + vmcs12->guest_idtr_base = vmcs_readl(GUEST_IDTR_BASE); + + vmcs12->guest_activity_state = vmcs_read32(GUEST_ACTIVITY_STATE); + vmcs12->guest_interruptibility_info = + vmcs_read32(GUEST_INTERRUPTIBILITY_INFO); + vmcs12->guest_pending_dbg_exceptions = + vmcs_readl(GUEST_PENDING_DBG_EXCEPTIONS); + + /* TODO: These cannot have changed unless we have MSR bitmaps and + * the relevant bit asks not to trap the change */ + vmcs12->guest_ia32_debugctl = vmcs_read64(GUEST_IA32_DEBUGCTL); + if (vmcs12->vm_entry_controls & VM_EXIT_SAVE_IA32_PAT) + vmcs12->guest_ia32_pat = vmcs_read64(GUEST_IA32_PAT); + vmcs12->guest_sysenter_cs = vmcs_read32(GUEST_SYSENTER_CS); + vmcs12->guest_sysenter_esp = vmcs_readl(GUEST_SYSENTER_ESP); + vmcs12->guest_sysenter_eip = vmcs_readl(GUEST_SYSENTER_EIP); + + /* update exit information fields: */ + + vmcs12->vm_exit_reason = vmcs_read32(VM_EXIT_REASON); + vmcs12->exit_qualification = vmcs_readl(EXIT_QUALIFICATION); + + vmcs12->vm_exit_intr_info = vmcs_read32(VM_EXIT_INTR_INFO); + vmcs12->vm_exit_intr_error_code = vmcs_read32(VM_EXIT_INTR_ERROR_CODE); + vmcs12->idt_vectoring_info_field = + vmcs_read32(IDT_VECTORING_INFO_FIELD); + vmcs12->idt_vectoring_error_code = + vmcs_read32(IDT_VECTORING_ERROR_CODE); + vmcs12->vm_exit_instruction_len = vmcs_read32(VM_EXIT_INSTRUCTION_LEN); + vmcs12->vmx_instruction_info = vmcs_read32(VMX_INSTRUCTION_INFO); + + /* clear vm-entry fields which are to be cleared on exit */ + if (!(vmcs12->vm_exit_reason & VMX_EXIT_REASONS_FAILED_VMENTRY)) + vmcs12->vm_entry_intr_info_field &= ~INTR_INFO_VALID_MASK; +} + +/* + * A part of what we need to when the nested L2 guest exits and we want to + * run its L1 parent, is to reset L1's guest state to the host state specified + * in vmcs12. + * This function is to be called not only on normal nested exit, but also on + * a nested entry failure, as explained in Intel's spec, 3B.23.7 ("VM-Entry + * Failures During or After Loading Guest State"). + * This function should be called when the active VMCS is L1's (vmcs01). + */ +void load_vmcs12_host_state(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) +{ + if (vmcs12->vm_exit_controls & VM_EXIT_LOAD_IA32_EFER) + vcpu->arch.efer = vmcs12->host_ia32_efer; + if (vmcs12->vm_exit_controls & VM_EXIT_HOST_ADDR_SPACE_SIZE) + vcpu->arch.efer |= (EFER_LMA | EFER_LME); + else + vcpu->arch.efer &= ~(EFER_LMA | EFER_LME); + vmx_set_efer(vcpu, vcpu->arch.efer); + + kvm_register_write(vcpu, VCPU_REGS_RSP, vmcs12->host_rsp); + kvm_register_write(vcpu, VCPU_REGS_RIP, vmcs12->host_rip); + /* + * Note that calling vmx_set_cr0 is important, even if cr0 hasn't + * actually changed, because it depends on the current state of + * fpu_active (which may have changed). + * Note that vmx_set_cr0 refers to efer set above. + */ + kvm_set_cr0(vcpu, vmcs12->host_cr0); + /* + * If we did fpu_activate()/fpu_deactivate() during L2's run, we need + * to apply the same changes to L1's vmcs. We just set cr0 correctly, + * but we also need to update cr0_guest_host_mask and exception_bitmap. + */ + update_exception_bitmap(vcpu); + vcpu->arch.cr0_guest_owned_bits = (vcpu->fpu_active ? X86_CR0_TS : 0); + vmcs_writel(CR0_GUEST_HOST_MASK, ~vcpu->arch.cr0_guest_owned_bits); + + /* + * Note that CR4_GUEST_HOST_MASK is already set in the original vmcs01 + * (KVM doesn't change it)- no reason to call set_cr4_guest_host_mask(); + */ + 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 */ + kvm_set_cr3(vcpu, vmcs12->host_cr3); + kvm_mmu_reset_context(vcpu); + + if (enable_vpid) { + /* + * Trivially support vpid by letting L2s share their parent + * L1's vpid. TODO: move to a more elaborate solution, giving + * each L2 its own vpid and exposing the vpid feature to L1. + */ + vmx_flush_tlb(vcpu); + } + + + vmcs_write32(GUEST_SYSENTER_CS, vmcs12->host_ia32_sysenter_cs); + vmcs_writel(GUEST_SYSENTER_ESP, vmcs12->host_ia32_sysenter_esp); + vmcs_writel(GUEST_SYSENTER_EIP, vmcs12->host_ia32_sysenter_eip); + vmcs_writel(GUEST_IDTR_BASE, vmcs12->host_idtr_base); + vmcs_writel(GUEST_GDTR_BASE, vmcs12->host_gdtr_base); + vmcs_writel(GUEST_TR_BASE, vmcs12->host_tr_base); + vmcs_writel(GUEST_GS_BASE, vmcs12->host_gs_base); + vmcs_writel(GUEST_FS_BASE, vmcs12->host_fs_base); + vmcs_write16(GUEST_ES_SELECTOR, vmcs12->host_es_selector); + vmcs_write16(GUEST_CS_SELECTOR, vmcs12->host_cs_selector); + vmcs_write16(GUEST_SS_SELECTOR, vmcs12->host_ss_selector); + vmcs_write16(GUEST_DS_SELECTOR, vmcs12->host_ds_selector); + vmcs_write16(GUEST_FS_SELECTOR, vmcs12->host_fs_selector); + vmcs_write16(GUEST_GS_SELECTOR, vmcs12->host_gs_selector); + vmcs_write16(GUEST_TR_SELECTOR, vmcs12->host_tr_selector); + + if (vmcs12->vm_exit_controls & VM_EXIT_LOAD_IA32_PAT) + vmcs_write64(GUEST_IA32_PAT, vmcs12->host_ia32_pat); + if (vmcs12->vm_exit_controls & VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL) + vmcs_write64(GUEST_IA32_PERF_GLOBAL_CTRL, + vmcs12->host_ia32_perf_global_ctrl); +} + +/* + * Emulate an exit from nested guest (L2) to L1, i.e., prepare to run L1 + * and modify vmcs12 to make it see what it would expect to see there if + * L2 was its real guest. Must only be called when in L2 (is_guest_mode()) + */ +static void nested_vmx_vmexit(struct kvm_vcpu *vcpu) +{ + struct vcpu_vmx *vmx = to_vmx(vcpu); + int cpu; + struct vmcs12 *vmcs12 = get_vmcs12(vcpu); + + leave_guest_mode(vcpu); + prepare_vmcs12(vcpu, vmcs12); + + cpu = get_cpu(); + vmx->loaded_vmcs = &vmx->vmcs01; + vmx_vcpu_put(vcpu); + vmx_vcpu_load(vcpu, cpu); + vcpu->cpu = cpu; + put_cpu(); + + /* if no vmcs02 cache requested, remove the one we used */ + if (VMCS02_POOL_SIZE == 0) + nested_free_vmcs02(vmx, vmx->nested.current_vmptr); + + load_vmcs12_host_state(vcpu, vmcs12); + + /* Update TSC_OFFSET if vmx_adjust_tsc_offset() was used while L2 ran */ + vmcs_write64(TSC_OFFSET, vmx->nested.vmcs01_tsc_offset); + + /* This is needed for same reason as it was needed in prepare_vmcs02 */ + vmx->host_rsp = 0; + + /* Unpin physical memory we referred to in vmcs02 */ + if (vmx->nested.apic_access_page) { + nested_release_page(vmx->nested.apic_access_page); + vmx->nested.apic_access_page = 0; + } + + /* + * Exiting from L2 to L1, we're now back to L1 which thinks it just + * finished a VMLAUNCH or VMRESUME instruction, so we need to set the + * success or failure flag accordingly. + */ + if (unlikely(vmx->fail)) { + vmx->fail = 0; + nested_vmx_failValid(vcpu, vmcs_read32(VM_INSTRUCTION_ERROR)); + } else + nested_vmx_succeed(vcpu); +} + static int vmx_check_intercept(struct kvm_vcpu *vcpu, struct x86_instruction_info *info, enum x86_intercept_stage stage) |