diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 4bd878c9f7d2..90b7eee6d0f9 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -11846,24 +11846,6 @@ static void prepare_vmcs12(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, kvm_clear_interrupt_queue(vcpu); } -static void load_vmcs12_mmu_host_state(struct kvm_vcpu *vcpu, - struct vmcs12 *vmcs12) -{ - u32 entry_failure_code; - - nested_ept_uninit_mmu_context(vcpu); - - /* - * Only PDPTE load can fail as the value of cr3 was checked on entry and - * couldn't have changed. - */ - if (nested_vmx_load_cr3(vcpu, vmcs12->host_cr3, false, &entry_failure_code)) - nested_vmx_abort(vcpu, VMX_ABORT_LOAD_HOST_PDPTE_FAIL); - - if (!enable_ept) - vcpu->arch.walk_mmu->inject_page_fault = kvm_inject_page_fault; -} - /* * 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 @@ -11877,6 +11859,7 @@ static void load_vmcs12_host_state(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) { struct kvm_segment seg; + u32 entry_failure_code; if (vmcs12->vm_exit_controls & VM_EXIT_LOAD_IA32_EFER) vcpu->arch.efer = vmcs12->host_ia32_efer; @@ -11903,7 +11886,17 @@ static void load_vmcs12_host_state(struct kvm_vcpu *vcpu, vcpu->arch.cr4_guest_owned_bits = ~vmcs_readl(CR4_GUEST_HOST_MASK); vmx_set_cr4(vcpu, vmcs12->host_cr4); - load_vmcs12_mmu_host_state(vcpu, vmcs12); + nested_ept_uninit_mmu_context(vcpu); + + /* + * Only PDPTE load can fail as the value of cr3 was checked on entry and + * couldn't have changed. + */ + if (nested_vmx_load_cr3(vcpu, vmcs12->host_cr3, false, &entry_failure_code)) + nested_vmx_abort(vcpu, VMX_ABORT_LOAD_HOST_PDPTE_FAIL); + + if (!enable_ept) + vcpu->arch.walk_mmu->inject_page_fault = kvm_inject_page_fault; if (enable_vpid) { /* @@ -11994,6 +11987,140 @@ static void load_vmcs12_host_state(struct kvm_vcpu *vcpu, nested_vmx_abort(vcpu, VMX_ABORT_LOAD_HOST_MSR_FAIL); } +static inline u64 nested_vmx_get_vmcs01_guest_efer(struct vcpu_vmx *vmx) +{ + struct shared_msr_entry *efer_msr; + unsigned int i; + + if (vm_entry_controls_get(vmx) & VM_ENTRY_LOAD_IA32_EFER) + return vmcs_read64(GUEST_IA32_EFER); + + if (cpu_has_load_ia32_efer) + return host_efer; + + for (i = 0; i < vmx->msr_autoload.guest.nr; ++i) { + if (vmx->msr_autoload.guest.val[i].index == MSR_EFER) + return vmx->msr_autoload.guest.val[i].value; + } + + efer_msr = find_msr_entry(vmx, MSR_EFER); + if (efer_msr) + return efer_msr->data; + + return host_efer; +} + +static void nested_vmx_restore_host_state(struct kvm_vcpu *vcpu) +{ + struct vmcs12 *vmcs12 = get_vmcs12(vcpu); + struct vcpu_vmx *vmx = to_vmx(vcpu); + struct vmx_msr_entry g, h; + struct msr_data msr; + gpa_t gpa; + u32 i, j; + + vcpu->arch.pat = vmcs_read64(GUEST_IA32_PAT); + + if (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_DEBUG_CONTROLS) { + /* + * L1's host DR7 is lost if KVM_GUESTDBG_USE_HW_BP is set + * as vmcs01.GUEST_DR7 contains a userspace defined value + * and vcpu->arch.dr7 is not squirreled away before the + * nested VMENTER (not worth adding a variable in nested_vmx). + */ + if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP) + kvm_set_dr(vcpu, 7, DR7_FIXED_1); + else + WARN_ON(kvm_set_dr(vcpu, 7, vmcs_readl(GUEST_DR7))); + } + + /* + * Note that calling vmx_set_{efer,cr0,cr4} is important as they + * handle a variety of side effects to KVM's software model. + */ + vmx_set_efer(vcpu, nested_vmx_get_vmcs01_guest_efer(vmx)); + + vcpu->arch.cr0_guest_owned_bits = X86_CR0_TS; + vmx_set_cr0(vcpu, vmcs_readl(CR0_READ_SHADOW)); + + vcpu->arch.cr4_guest_owned_bits = ~vmcs_readl(CR4_GUEST_HOST_MASK); + vmx_set_cr4(vcpu, vmcs_readl(CR4_READ_SHADOW)); + + nested_ept_uninit_mmu_context(vcpu); + vcpu->arch.cr3 = vmcs_readl(GUEST_CR3); + __set_bit(VCPU_EXREG_CR3, (ulong *)&vcpu->arch.regs_avail); + + /* + * Use ept_save_pdptrs(vcpu) to load the MMU's cached PDPTRs + * from vmcs01 (if necessary). The PDPTRs are not loaded on + * VMFail, like everything else we just need to ensure our + * software model is up-to-date. + */ + ept_save_pdptrs(vcpu); + + kvm_mmu_reset_context(vcpu); + + if (cpu_has_vmx_msr_bitmap()) + vmx_update_msr_bitmap(vcpu); + + /* + * This nasty bit of open coding is a compromise between blindly + * loading L1's MSRs using the exit load lists (incorrect emulation + * of VMFail), leaving the nested VM's MSRs in the software model + * (incorrect behavior) and snapshotting the modified MSRs (too + * expensive since the lists are unbound by hardware). For each + * MSR that was (prematurely) loaded from the nested VMEntry load + * list, reload it from the exit load list if it exists and differs + * from the guest value. The intent is to stuff host state as + * silently as possible, not to fully process the exit load list. + */ + msr.host_initiated = false; + for (i = 0; i < vmcs12->vm_entry_msr_load_count; i++) { + gpa = vmcs12->vm_entry_msr_load_addr + (i * sizeof(g)); + if (kvm_vcpu_read_guest(vcpu, gpa, &g, sizeof(g))) { + pr_debug_ratelimited( + "%s read MSR index failed (%u, 0x%08llx)\n", + __func__, i, gpa); + goto vmabort; + } + + for (j = 0; j < vmcs12->vm_exit_msr_load_count; j++) { + gpa = vmcs12->vm_exit_msr_load_addr + (j * sizeof(h)); + if (kvm_vcpu_read_guest(vcpu, gpa, &h, sizeof(h))) { + pr_debug_ratelimited( + "%s read MSR failed (%u, 0x%08llx)\n", + __func__, j, gpa); + goto vmabort; + } + if (h.index != g.index) + continue; + if (h.value == g.value) + break; + + if (nested_vmx_load_msr_check(vcpu, &h)) { + pr_debug_ratelimited( + "%s check failed (%u, 0x%x, 0x%x)\n", + __func__, j, h.index, h.reserved); + goto vmabort; + } + + msr.index = h.index; + msr.data = h.value; + if (kvm_set_msr(vcpu, &msr)) { + pr_debug_ratelimited( + "%s WRMSR failed (%u, 0x%x, 0x%llx)\n", + __func__, j, h.index, h.value); + goto vmabort; + } + } + } + + return; + +vmabort: + nested_vmx_abort(vcpu, VMX_ABORT_LOAD_HOST_MSR_FAIL); +} + /* * 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 @@ -12126,7 +12253,13 @@ static void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 exit_reason, */ nested_vmx_failValid(vcpu, VMXERR_ENTRY_INVALID_CONTROL_FIELD); - load_vmcs12_mmu_host_state(vcpu, vmcs12); + /* + * Restore L1's host state to KVM's software model. We're here + * because a consistency check was caught by hardware, which + * means some amount of guest state has been propagated to KVM's + * model and needs to be unwound to the host's state. + */ + nested_vmx_restore_host_state(vcpu); /* * The emulated instruction was already skipped in