diff options
| -rw-r--r-- | arch/x86/kvm/vmx.c | 253 |
1 files changed, 252 insertions, 1 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index ee25b9fdfa82..7f62dc36af9b 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -346,6 +346,8 @@ struct nested_vmx { struct list_head vmcs02_pool; int vmcs02_num; u64 vmcs01_tsc_offset; + /* L2 must run next, and mustn't decide to exit to L1. */ + bool nested_run_pending; /* * Guest pages referred to in vmcs02 with host-physical pointers, so * we must keep them pinned while L2 runs. @@ -865,6 +867,19 @@ static inline bool nested_cpu_has2(struct vmcs12 *vmcs12, u32 bit) (vmcs12->secondary_vm_exec_control & bit); } +static inline bool nested_cpu_has_virtual_nmis(struct vmcs12 *vmcs12, + struct kvm_vcpu *vcpu) +{ + return vmcs12->pin_based_vm_exec_control & PIN_BASED_VIRTUAL_NMIS; +} + +static inline bool is_exception(u32 intr_info) +{ + return (intr_info & (INTR_INFO_INTR_TYPE_MASK | INTR_INFO_VALID_MASK)) + == (INTR_TYPE_HARD_EXCEPTION | INTR_INFO_VALID_MASK); +} + +static void nested_vmx_vmexit(struct kvm_vcpu *vcpu); static void nested_vmx_entry_failure(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, u32 reason, unsigned long qualification); @@ -5277,6 +5292,229 @@ static int (*kvm_vmx_exit_handlers[])(struct kvm_vcpu *vcpu) = { static const int kvm_vmx_max_exit_handlers = ARRAY_SIZE(kvm_vmx_exit_handlers); +/* + * Return 1 if we should exit from L2 to L1 to handle an MSR access access, + * rather than handle it ourselves in L0. I.e., check whether L1 expressed + * disinterest in the current event (read or write a specific MSR) by using an + * MSR bitmap. This may be the case even when L0 doesn't use MSR bitmaps. + */ +static bool nested_vmx_exit_handled_msr(struct kvm_vcpu *vcpu, + struct vmcs12 *vmcs12, u32 exit_reason) +{ + u32 msr_index = vcpu->arch.regs[VCPU_REGS_RCX]; + gpa_t bitmap; + + if (!nested_cpu_has(get_vmcs12(vcpu), CPU_BASED_USE_MSR_BITMAPS)) + return 1; + + /* + * The MSR_BITMAP page is divided into four 1024-byte bitmaps, + * for the four combinations of read/write and low/high MSR numbers. + * First we need to figure out which of the four to use: + */ + bitmap = vmcs12->msr_bitmap; + if (exit_reason == EXIT_REASON_MSR_WRITE) + bitmap += 2048; + if (msr_index >= 0xc0000000) { + msr_index -= 0xc0000000; + bitmap += 1024; + } + + /* Then read the msr_index'th bit from this bitmap: */ + if (msr_index < 1024*8) { + unsigned char b; + kvm_read_guest(vcpu->kvm, bitmap + msr_index/8, &b, 1); + return 1 & (b >> (msr_index & 7)); + } else + return 1; /* let L1 handle the wrong parameter */ +} + +/* + * Return 1 if we should exit from L2 to L1 to handle a CR access exit, + * rather than handle it ourselves in L0. I.e., check if L1 wanted to + * intercept (via guest_host_mask etc.) the current event. + */ +static bool nested_vmx_exit_handled_cr(struct kvm_vcpu *vcpu, + struct vmcs12 *vmcs12) +{ + unsigned long exit_qualification = vmcs_readl(EXIT_QUALIFICATION); + int cr = exit_qualification & 15; + int reg = (exit_qualification >> 8) & 15; + unsigned long val = kvm_register_read(vcpu, reg); + + switch ((exit_qualification >> 4) & 3) { + case 0: /* mov to cr */ + switch (cr) { + case 0: + if (vmcs12->cr0_guest_host_mask & + (val ^ vmcs12->cr0_read_shadow)) + return 1; + break; + case 3: + if ((vmcs12->cr3_target_count >= 1 && + vmcs12->cr3_target_value0 == val) || + (vmcs12->cr3_target_count >= 2 && + vmcs12->cr3_target_value1 == val) || + (vmcs12->cr3_target_count >= 3 && + vmcs12->cr3_target_value2 == val) || + (vmcs12->cr3_target_count >= 4 && + vmcs12->cr3_target_value3 == val)) + return 0; + if (nested_cpu_has(vmcs12, CPU_BASED_CR3_LOAD_EXITING)) + return 1; + break; + case 4: + if (vmcs12->cr4_guest_host_mask & + (vmcs12->cr4_read_shadow ^ val)) + return 1; + break; + case 8: + if (nested_cpu_has(vmcs12, CPU_BASED_CR8_LOAD_EXITING)) + return 1; + break; + } + break; + case 2: /* clts */ + if ((vmcs12->cr0_guest_host_mask & X86_CR0_TS) && + (vmcs12->cr0_read_shadow & X86_CR0_TS)) + return 1; + break; + case 1: /* mov from cr */ + switch (cr) { + case 3: + if (vmcs12->cpu_based_vm_exec_control & + CPU_BASED_CR3_STORE_EXITING) + return 1; + break; + case 8: + if (vmcs12->cpu_based_vm_exec_control & + CPU_BASED_CR8_STORE_EXITING) + return 1; + break; + } + break; + case 3: /* lmsw */ + /* + * lmsw can change bits 1..3 of cr0, and only set bit 0 of + * cr0. Other attempted changes are ignored, with no exit. + */ + if (vmcs12->cr0_guest_host_mask & 0xe & + (val ^ vmcs12->cr0_read_shadow)) + return 1; + if ((vmcs12->cr0_guest_host_mask & 0x1) && + !(vmcs12->cr0_read_shadow & 0x1) && + (val & 0x1)) + return 1; + break; + } + return 0; +} + +/* + * Return 1 if we should exit from L2 to L1 to handle an exit, or 0 if we + * should handle it ourselves in L0 (and then continue L2). Only call this + * when in is_guest_mode (L2). + */ +static bool nested_vmx_exit_handled(struct kvm_vcpu *vcpu) +{ + u32 exit_reason = vmcs_read32(VM_EXIT_REASON); + u32 intr_info = vmcs_read32(VM_EXIT_INTR_INFO); + struct vcpu_vmx *vmx = to_vmx(vcpu); + struct vmcs12 *vmcs12 = get_vmcs12(vcpu); + + if (vmx->nested.nested_run_pending) + return 0; + + if (unlikely(vmx->fail)) { + printk(KERN_INFO "%s failed vm entry %x\n", + __func__, vmcs_read32(VM_INSTRUCTION_ERROR)); + return 1; + } + + switch (exit_reason) { + case EXIT_REASON_EXCEPTION_NMI: + if (!is_exception(intr_info)) + return 0; + else if (is_page_fault(intr_info)) + return enable_ept; + return vmcs12->exception_bitmap & + (1u << (intr_info & INTR_INFO_VECTOR_MASK)); + case EXIT_REASON_EXTERNAL_INTERRUPT: + return 0; + case EXIT_REASON_TRIPLE_FAULT: + return 1; + case EXIT_REASON_PENDING_INTERRUPT: + case EXIT_REASON_NMI_WINDOW: + /* + * prepare_vmcs02() set the CPU_BASED_VIRTUAL_INTR_PENDING bit + * (aka Interrupt Window Exiting) only when L1 turned it on, + * so if we got a PENDING_INTERRUPT exit, this must be for L1. + * Same for NMI Window Exiting. + */ + return 1; + case EXIT_REASON_TASK_SWITCH: + return 1; + case EXIT_REASON_CPUID: + return 1; + case EXIT_REASON_HLT: + return nested_cpu_has(vmcs12, CPU_BASED_HLT_EXITING); + case EXIT_REASON_INVD: + return 1; + case EXIT_REASON_INVLPG: + return nested_cpu_has(vmcs12, CPU_BASED_INVLPG_EXITING); + case EXIT_REASON_RDPMC: + return nested_cpu_has(vmcs12, CPU_BASED_RDPMC_EXITING); + case EXIT_REASON_RDTSC: + return nested_cpu_has(vmcs12, CPU_BASED_RDTSC_EXITING); + case EXIT_REASON_VMCALL: case EXIT_REASON_VMCLEAR: + case EXIT_REASON_VMLAUNCH: case EXIT_REASON_VMPTRLD: + case EXIT_REASON_VMPTRST: case EXIT_REASON_VMREAD: + case EXIT_REASON_VMRESUME: case EXIT_REASON_VMWRITE: + case EXIT_REASON_VMOFF: case EXIT_REASON_VMON: + /* + * VMX instructions trap unconditionally. This allows L1 to + * emulate them for its L2 guest, i.e., allows 3-level nesting! + */ + return 1; + case EXIT_REASON_CR_ACCESS: + return nested_vmx_exit_handled_cr(vcpu, vmcs12); + case EXIT_REASON_DR_ACCESS: + return nested_cpu_has(vmcs12, CPU_BASED_MOV_DR_EXITING); + case EXIT_REASON_IO_INSTRUCTION: + /* TODO: support IO bitmaps */ + return 1; + case EXIT_REASON_MSR_READ: + case EXIT_REASON_MSR_WRITE: + return nested_vmx_exit_handled_msr(vcpu, vmcs12, exit_reason); + case EXIT_REASON_INVALID_STATE: + return 1; + case EXIT_REASON_MWAIT_INSTRUCTION: + return nested_cpu_has(vmcs12, CPU_BASED_MWAIT_EXITING); + case EXIT_REASON_MONITOR_INSTRUCTION: + return nested_cpu_has(vmcs12, CPU_BASED_MONITOR_EXITING); + case EXIT_REASON_PAUSE_INSTRUCTION: + return nested_cpu_has(vmcs12, CPU_BASED_PAUSE_EXITING) || + nested_cpu_has2(vmcs12, + SECONDARY_EXEC_PAUSE_LOOP_EXITING); + case EXIT_REASON_MCE_DURING_VMENTRY: + return 0; + case EXIT_REASON_TPR_BELOW_THRESHOLD: + return 1; + case EXIT_REASON_APIC_ACCESS: + return nested_cpu_has2(vmcs12, + SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES); + case EXIT_REASON_EPT_VIOLATION: + case EXIT_REASON_EPT_MISCONFIG: + return 0; + case EXIT_REASON_WBINVD: + return nested_cpu_has2(vmcs12, SECONDARY_EXEC_WBINVD_EXITING); + case EXIT_REASON_XSETBV: + return 1; + default: + return 1; + } +} + static void vmx_get_exit_info(struct kvm_vcpu *vcpu, u64 *info1, u64 *info2) { *info1 = vmcs_readl(EXIT_QUALIFICATION); @@ -5299,6 +5537,17 @@ static int vmx_handle_exit(struct kvm_vcpu *vcpu) if (vmx->emulation_required && emulate_invalid_guest_state) return handle_invalid_guest_state(vcpu); + if (exit_reason == EXIT_REASON_VMLAUNCH || + exit_reason == EXIT_REASON_VMRESUME) + vmx->nested.nested_run_pending = 1; + else + vmx->nested.nested_run_pending = 0; + + if (is_guest_mode(vcpu) && nested_vmx_exit_handled(vcpu)) { + nested_vmx_vmexit(vcpu); + return 1; + } + if (exit_reason & VMX_EXIT_REASONS_FAILED_VMENTRY) { vcpu->run->exit_reason = KVM_EXIT_FAIL_ENTRY; vcpu->run->fail_entry.hardware_entry_failure_reason @@ -5321,7 +5570,9 @@ static int vmx_handle_exit(struct kvm_vcpu *vcpu) "(0x%x) and exit reason is 0x%x\n", __func__, vectoring_info, exit_reason); - if (unlikely(!cpu_has_virtual_nmis() && vmx->soft_vnmi_blocked)) { + if (unlikely(!cpu_has_virtual_nmis() && vmx->soft_vnmi_blocked && + !(is_guest_mode(vcpu) && nested_cpu_has_virtual_nmis( + get_vmcs12(vcpu), vcpu)))) { if (vmx_interrupt_allowed(vcpu)) { vmx->soft_vnmi_blocked = 0; } else if (vmx->vnmi_blocked_time > 1000000000LL && |