diff options
| -rw-r--r-- | arch/x86/include/asm/vmx.h | 8 | ||||
| -rw-r--r-- | arch/x86/kvm/vmx.c | 101 |
2 files changed, 109 insertions, 0 deletions
diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h index b747773cf83b..2caf290e9895 100644 --- a/arch/x86/include/asm/vmx.h +++ b/arch/x86/include/asm/vmx.h @@ -431,6 +431,14 @@ struct vmx_msr_entry { } __aligned(16); /* + * Exit Qualifications for entry failure during or after loading guest state + */ +#define ENTRY_FAIL_DEFAULT 0 +#define ENTRY_FAIL_PDPTE 2 +#define ENTRY_FAIL_NMI 3 +#define ENTRY_FAIL_VMCS_LINK_PTR 4 + +/* * VM-instruction error numbers */ enum vm_instruction_error_number { diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 7d778e4976ea..ee25b9fdfa82 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -865,6 +865,10 @@ static inline bool nested_cpu_has2(struct vmcs12 *vmcs12, u32 bit) (vmcs12->secondary_vm_exec_control & bit); } +static void nested_vmx_entry_failure(struct kvm_vcpu *vcpu, + struct vmcs12 *vmcs12, + u32 reason, unsigned long qualification); + static int __find_msr_index(struct vcpu_vmx *vmx, u32 msr) { int i; @@ -6116,6 +6120,86 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch) skip_emulated_instruction(vcpu); vmcs12 = get_vmcs12(vcpu); + /* + * The nested entry process starts with enforcing various prerequisites + * on vmcs12 as required by the Intel SDM, and act appropriately when + * they fail: As the SDM explains, some conditions should cause the + * instruction to fail, while others will cause the instruction to seem + * to succeed, but return an EXIT_REASON_INVALID_STATE. + * To speed up the normal (success) code path, we should avoid checking + * for misconfigurations which will anyway be caught by the processor + * when using the merged vmcs02. + */ + if (vmcs12->launch_state == launch) { + nested_vmx_failValid(vcpu, + launch ? VMXERR_VMLAUNCH_NONCLEAR_VMCS + : VMXERR_VMRESUME_NONLAUNCHED_VMCS); + return 1; + } + + if ((vmcs12->cpu_based_vm_exec_control & CPU_BASED_USE_MSR_BITMAPS) && + !IS_ALIGNED(vmcs12->msr_bitmap, PAGE_SIZE)) { + /*TODO: Also verify bits beyond physical address width are 0*/ + nested_vmx_failValid(vcpu, VMXERR_ENTRY_INVALID_CONTROL_FIELD); + return 1; + } + + if (nested_cpu_has2(vmcs12, SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES) && + !IS_ALIGNED(vmcs12->apic_access_addr, PAGE_SIZE)) { + /*TODO: Also verify bits beyond physical address width are 0*/ + nested_vmx_failValid(vcpu, VMXERR_ENTRY_INVALID_CONTROL_FIELD); + return 1; + } + + if (vmcs12->vm_entry_msr_load_count > 0 || + vmcs12->vm_exit_msr_load_count > 0 || + vmcs12->vm_exit_msr_store_count > 0) { + if (printk_ratelimit()) + printk(KERN_WARNING + "%s: VMCS MSR_{LOAD,STORE} unsupported\n", __func__); + nested_vmx_failValid(vcpu, VMXERR_ENTRY_INVALID_CONTROL_FIELD); + return 1; + } + + if (!vmx_control_verify(vmcs12->cpu_based_vm_exec_control, + nested_vmx_procbased_ctls_low, nested_vmx_procbased_ctls_high) || + !vmx_control_verify(vmcs12->secondary_vm_exec_control, + nested_vmx_secondary_ctls_low, nested_vmx_secondary_ctls_high) || + !vmx_control_verify(vmcs12->pin_based_vm_exec_control, + nested_vmx_pinbased_ctls_low, nested_vmx_pinbased_ctls_high) || + !vmx_control_verify(vmcs12->vm_exit_controls, + nested_vmx_exit_ctls_low, nested_vmx_exit_ctls_high) || + !vmx_control_verify(vmcs12->vm_entry_controls, + nested_vmx_entry_ctls_low, nested_vmx_entry_ctls_high)) + { + nested_vmx_failValid(vcpu, VMXERR_ENTRY_INVALID_CONTROL_FIELD); + return 1; + } + + if (((vmcs12->host_cr0 & VMXON_CR0_ALWAYSON) != VMXON_CR0_ALWAYSON) || + ((vmcs12->host_cr4 & VMXON_CR4_ALWAYSON) != VMXON_CR4_ALWAYSON)) { + nested_vmx_failValid(vcpu, + VMXERR_ENTRY_INVALID_HOST_STATE_FIELD); + return 1; + } + + if (((vmcs12->guest_cr0 & VMXON_CR0_ALWAYSON) != VMXON_CR0_ALWAYSON) || + ((vmcs12->guest_cr4 & VMXON_CR4_ALWAYSON) != VMXON_CR4_ALWAYSON)) { + nested_vmx_entry_failure(vcpu, vmcs12, + EXIT_REASON_INVALID_STATE, ENTRY_FAIL_DEFAULT); + return 1; + } + if (vmcs12->vmcs_link_pointer != -1ull) { + nested_vmx_entry_failure(vcpu, vmcs12, + EXIT_REASON_INVALID_STATE, ENTRY_FAIL_VMCS_LINK_PTR); + return 1; + } + + /* + * We're finally done with prerequisite checking, and can start with + * the nested entry. + */ + vmcs02 = nested_get_current_vmcs02(vmx); if (!vmcs02) return -ENOMEM; @@ -6406,6 +6490,23 @@ static void nested_vmx_vmexit(struct kvm_vcpu *vcpu) nested_vmx_succeed(vcpu); } +/* + * L1's failure to enter L2 is a subset of a normal exit, as explained in + * 23.7 "VM-entry failures during or after loading guest state" (this also + * lists the acceptable exit-reason and exit-qualification parameters). + * It should only be called before L2 actually succeeded to run, and when + * vmcs01 is current (it doesn't leave_guest_mode() or switch vmcss). + */ +static void nested_vmx_entry_failure(struct kvm_vcpu *vcpu, + struct vmcs12 *vmcs12, + u32 reason, unsigned long qualification) +{ + load_vmcs12_host_state(vcpu, vmcs12); + vmcs12->vm_exit_reason = reason | VMX_EXIT_REASONS_FAILED_VMENTRY; + vmcs12->exit_qualification = qualification; + nested_vmx_succeed(vcpu); +} + static int vmx_check_intercept(struct kvm_vcpu *vcpu, struct x86_instruction_info *info, enum x86_intercept_stage stage) |
