diff options
| -rw-r--r-- | arch/x86/kvm/vmx.c | 193 |
1 files changed, 191 insertions, 2 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 2bc521c..84d9c93 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -4877,6 +4877,195 @@ static int handle_vmclear(struct kvm_vcpu *vcpu) return 1; } +enum vmcs_field_type { + VMCS_FIELD_TYPE_U16 = 0, + VMCS_FIELD_TYPE_U64 = 1, + VMCS_FIELD_TYPE_U32 = 2, + VMCS_FIELD_TYPE_NATURAL_WIDTH = 3 +}; + +static inline int vmcs_field_type(unsigned long field) +{ + if (0x1 & field) /* the *_HIGH fields are all 32 bit */ + return VMCS_FIELD_TYPE_U32; + return (field >> 13) & 0x3 ; +} + +static inline int vmcs_field_readonly(unsigned long field) +{ + return (((field >> 10) & 0x3) == 1); +} + +/* + * Read a vmcs12 field. Since these can have varying lengths and we return + * one type, we chose the biggest type (u64) and zero-extend the return value + * to that size. Note that the caller, handle_vmread, might need to use only + * some of the bits we return here (e.g., on 32-bit guests, only 32 bits of + * 64-bit fields are to be returned). + */ +static inline bool vmcs12_read_any(struct kvm_vcpu *vcpu, + unsigned long field, u64 *ret) +{ + short offset = vmcs_field_to_offset(field); + char *p; + + if (offset < 0) + return 0; + + p = ((char *)(get_vmcs12(vcpu))) + offset; + + switch (vmcs_field_type(field)) { + case VMCS_FIELD_TYPE_NATURAL_WIDTH: + *ret = *((natural_width *)p); + return 1; + case VMCS_FIELD_TYPE_U16: + *ret = *((u16 *)p); + return 1; + case VMCS_FIELD_TYPE_U32: + *ret = *((u32 *)p); + return 1; + case VMCS_FIELD_TYPE_U64: + *ret = *((u64 *)p); + return 1; + default: + return 0; /* can never happen. */ + } +} + +/* + * VMX instructions which assume a current vmcs12 (i.e., that VMPTRLD was + * used before) all generate the same failure when it is missing. + */ +static int nested_vmx_check_vmcs12(struct kvm_vcpu *vcpu) +{ + struct vcpu_vmx *vmx = to_vmx(vcpu); + if (vmx->nested.current_vmptr == -1ull) { + nested_vmx_failInvalid(vcpu); + skip_emulated_instruction(vcpu); + return 0; + } + return 1; +} + +static int handle_vmread(struct kvm_vcpu *vcpu) +{ + unsigned long field; + u64 field_value; + unsigned long exit_qualification = vmcs_readl(EXIT_QUALIFICATION); + u32 vmx_instruction_info = vmcs_read32(VMX_INSTRUCTION_INFO); + gva_t gva = 0; + + if (!nested_vmx_check_permission(vcpu) || + !nested_vmx_check_vmcs12(vcpu)) + return 1; + + /* Decode instruction info and find the field to read */ + field = kvm_register_read(vcpu, (((vmx_instruction_info) >> 28) & 0xf)); + /* Read the field, zero-extended to a u64 field_value */ + if (!vmcs12_read_any(vcpu, field, &field_value)) { + nested_vmx_failValid(vcpu, VMXERR_UNSUPPORTED_VMCS_COMPONENT); + skip_emulated_instruction(vcpu); + return 1; + } + /* + * Now copy part of this value to register or memory, as requested. + * Note that the number of bits actually copied is 32 or 64 depending + * on the guest's mode (32 or 64 bit), not on the given field's length. + */ + if (vmx_instruction_info & (1u << 10)) { + kvm_register_write(vcpu, (((vmx_instruction_info) >> 3) & 0xf), + field_value); + } else { + if (get_vmx_mem_address(vcpu, exit_qualification, + vmx_instruction_info, &gva)) + return 1; + /* _system ok, as nested_vmx_check_permission verified cpl=0 */ + kvm_write_guest_virt_system(&vcpu->arch.emulate_ctxt, gva, + &field_value, (is_long_mode(vcpu) ? 8 : 4), NULL); + } + + nested_vmx_succeed(vcpu); + skip_emulated_instruction(vcpu); + return 1; +} + + +static int handle_vmwrite(struct kvm_vcpu *vcpu) +{ + unsigned long field; + gva_t gva; + unsigned long exit_qualification = vmcs_readl(EXIT_QUALIFICATION); + u32 vmx_instruction_info = vmcs_read32(VMX_INSTRUCTION_INFO); + char *p; + short offset; + /* The value to write might be 32 or 64 bits, depending on L1's long + * mode, and eventually we need to write that into a field of several + * possible lengths. The code below first zero-extends the value to 64 + * bit (field_value), and then copies only the approriate number of + * bits into the vmcs12 field. + */ + u64 field_value = 0; + struct x86_exception e; + + if (!nested_vmx_check_permission(vcpu) || + !nested_vmx_check_vmcs12(vcpu)) + return 1; + + if (vmx_instruction_info & (1u << 10)) + field_value = kvm_register_read(vcpu, + (((vmx_instruction_info) >> 3) & 0xf)); + else { + if (get_vmx_mem_address(vcpu, exit_qualification, + vmx_instruction_info, &gva)) + return 1; + if (kvm_read_guest_virt(&vcpu->arch.emulate_ctxt, gva, + &field_value, (is_long_mode(vcpu) ? 8 : 4), &e)) { + kvm_inject_page_fault(vcpu, &e); + return 1; + } + } + + + field = kvm_register_read(vcpu, (((vmx_instruction_info) >> 28) & 0xf)); + if (vmcs_field_readonly(field)) { + nested_vmx_failValid(vcpu, + VMXERR_VMWRITE_READ_ONLY_VMCS_COMPONENT); + skip_emulated_instruction(vcpu); + return 1; + } + + offset = vmcs_field_to_offset(field); + if (offset < 0) { + nested_vmx_failValid(vcpu, VMXERR_UNSUPPORTED_VMCS_COMPONENT); + skip_emulated_instruction(vcpu); + return 1; + } + p = ((char *) get_vmcs12(vcpu)) + offset; + + switch (vmcs_field_type(field)) { + case VMCS_FIELD_TYPE_U16: + *(u16 *)p = field_value; + break; + case VMCS_FIELD_TYPE_U32: + *(u32 *)p = field_value; + break; + case VMCS_FIELD_TYPE_U64: + *(u64 *)p = field_value; + break; + case VMCS_FIELD_TYPE_NATURAL_WIDTH: + *(natural_width *)p = field_value; + break; + default: + nested_vmx_failValid(vcpu, VMXERR_UNSUPPORTED_VMCS_COMPONENT); + skip_emulated_instruction(vcpu); + return 1; + } + + nested_vmx_succeed(vcpu); + skip_emulated_instruction(vcpu); + return 1; +} + /* Emulate the VMPTRLD instruction */ static int handle_vmptrld(struct kvm_vcpu *vcpu) { @@ -4988,9 +5177,9 @@ static int (*kvm_vmx_exit_handlers[])(struct kvm_vcpu *vcpu) = { [EXIT_REASON_VMLAUNCH] = handle_vmx_insn, [EXIT_REASON_VMPTRLD] = handle_vmptrld, [EXIT_REASON_VMPTRST] = handle_vmptrst, - [EXIT_REASON_VMREAD] = handle_vmx_insn, + [EXIT_REASON_VMREAD] = handle_vmread, [EXIT_REASON_VMRESUME] = handle_vmx_insn, - [EXIT_REASON_VMWRITE] = handle_vmx_insn, + [EXIT_REASON_VMWRITE] = handle_vmwrite, [EXIT_REASON_VMOFF] = handle_vmoff, [EXIT_REASON_VMON] = handle_vmon, [EXIT_REASON_TPR_BELOW_THRESHOLD] = handle_tpr_below_threshold, |