by Vitaly Kuznetsov

[permalink] [raw]

Subject: Re: [PATCH 3/5] KVM: nVMX: add enlightened VMCS state

Liran Alon <[email protected]> writes:

> ----- [email protected] wrote:
>
>> Adds hv_evmcs pointer and implement copy_enlightened_to_vmcs12() and
>> copy_enlightened_to_vmcs12().
>>
>> prepare_vmcs02()/prepare_vmcs02_full() separation is not valid for
>> Enlightened VMCS, do full sync for now.
>>
>> Suggested-by: Ladi Prosek <[email protected]>
>> Signed-off-by: Vitaly Kuznetsov <[email protected]>
>> ---
>> arch/x86/kvm/vmx.c | 431
>> +++++++++++++++++++++++++++++++++++++++++++++++++++--
>> 1 file changed, 417 insertions(+), 14 deletions(-)
>>
>> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
>> index 51749207cef1..e7fa9f9c6e36 100644
>> --- a/arch/x86/kvm/vmx.c
>> +++ b/arch/x86/kvm/vmx.c
>> @@ -640,10 +640,10 @@ struct nested_vmx {
>> */
>> struct vmcs12 *cached_vmcs12;
>> /*
>> - * Indicates if the shadow vmcs must be updated with the
>> - * data hold by vmcs12
>> + * Indicates if the shadow vmcs or enlightened vmcs must be updated
>> + * with the data held by struct vmcs12.
>> */
>> - bool sync_shadow_vmcs;
>> + bool need_vmcs12_sync;
>> bool dirty_vmcs12;
>>
>> bool change_vmcs01_virtual_apic_mode;
>> @@ -689,6 +689,8 @@ struct nested_vmx {
>> /* in guest mode on SMM entry? */
>> bool guest_mode;
>> } smm;
>> +
>> + struct hv_enlightened_vmcs *hv_evmcs;
>> };
>>
>> #define POSTED_INTR_ON 0
>> @@ -8010,7 +8012,7 @@ static inline void nested_release_vmcs12(struct
>> vcpu_vmx *vmx)
>> /* copy to memory all shadowed fields in case
>> they were modified */
>> copy_shadow_to_vmcs12(vmx);
>> - vmx->nested.sync_shadow_vmcs = false;
>> + vmx->nested.need_vmcs12_sync = false;
>> vmx_disable_shadow_vmcs(vmx);
>> }
>> vmx->nested.posted_intr_nv = -1;
>> @@ -8187,6 +8189,393 @@ static inline int vmcs12_write_any(struct
>> kvm_vcpu *vcpu,
>>
>> }
>>
>> +static int copy_enlightened_to_vmcs12(struct vcpu_vmx *vmx, bool
>> full)
>> +{
>> + struct vmcs12 *vmcs12 = vmx->nested.cached_vmcs12;
>> + struct hv_enlightened_vmcs *evmcs = vmx->nested.hv_evmcs;
>> +
>> + /* HV_VMX_ENLIGHTENED_CLEAN_FIELD_NONE */
>> + vmcs12->tpr_threshold = evmcs->tpr_threshold;
>> + vmcs12->guest_rip = evmcs->guest_rip;
>> +
>> + if (unlikely(full || !(evmcs->hv_clean_fields &
>> + HV_VMX_ENLIGHTENED_CLEAN_FIELD_GUEST_BASIC))) {
>> + vmcs12->guest_rsp = evmcs->guest_rsp;
>> + vmcs12->guest_rflags = evmcs->guest_rflags;
>> + vmcs12->guest_interruptibility_info =
>> + evmcs->guest_interruptibility_info;
>> + }
>> +
>> + if (unlikely(full || !(evmcs->hv_clean_fields &
>> + HV_VMX_ENLIGHTENED_CLEAN_FIELD_CONTROL_PROC))) {
>> + vmcs12->cpu_based_vm_exec_control =
>> + evmcs->cpu_based_vm_exec_control;
>> + }
>> +
>> + if (unlikely(full || !(evmcs->hv_clean_fields &
>> + HV_VMX_ENLIGHTENED_CLEAN_FIELD_CONTROL_PROC))) {
>> + vmcs12->exception_bitmap = evmcs->exception_bitmap;
>> + }
>> +
>> + if (unlikely(full || !(evmcs->hv_clean_fields &
>> + HV_VMX_ENLIGHTENED_CLEAN_FIELD_CONTROL_ENTRY))) {
>> + vmcs12->vm_entry_controls = evmcs->vm_entry_controls;
>> + }
>> +
>> + if (unlikely(full || !(evmcs->hv_clean_fields &
>> + HV_VMX_ENLIGHTENED_CLEAN_FIELD_CONTROL_EVENT))) {
>> + vmcs12->vm_entry_intr_info_field =
>> + evmcs->vm_entry_intr_info_field;
>> + vmcs12->vm_entry_exception_error_code =
>> + evmcs->vm_entry_exception_error_code;
>> + vmcs12->vm_entry_instruction_len =
>> + evmcs->vm_entry_instruction_len;
>> + }
>> +
>> + if (unlikely(full || !(evmcs->hv_clean_fields &
>> + HV_VMX_ENLIGHTENED_CLEAN_FIELD_HOST_GRP1))) {
>> + vmcs12->host_ia32_pat = evmcs->host_ia32_pat;
>> + vmcs12->host_ia32_efer = evmcs->host_ia32_efer;
>> + vmcs12->host_cr0 = evmcs->host_cr0;
>> + vmcs12->host_cr3 = evmcs->host_cr3;
>> + vmcs12->host_cr4 = evmcs->host_cr4;
>> + vmcs12->host_ia32_sysenter_esp = evmcs->host_ia32_sysenter_esp;
>> + vmcs12->host_ia32_sysenter_eip = evmcs->host_ia32_sysenter_eip;
>> + vmcs12->host_rip = evmcs->host_rip;
>> + vmcs12->host_ia32_sysenter_cs = evmcs->host_ia32_sysenter_cs;
>> + vmcs12->host_es_selector = evmcs->host_es_selector;
>> + vmcs12->host_cs_selector = evmcs->host_cs_selector;
>> + vmcs12->host_ss_selector = evmcs->host_ss_selector;
>> + vmcs12->host_ds_selector = evmcs->host_ds_selector;
>> + vmcs12->host_fs_selector = evmcs->host_fs_selector;
>> + vmcs12->host_gs_selector = evmcs->host_gs_selector;
>> + vmcs12->host_tr_selector = evmcs->host_tr_selector;
>> + }
>> +
>> + if (unlikely(full || !(evmcs->hv_clean_fields &
>> + HV_VMX_ENLIGHTENED_CLEAN_FIELD_HOST_GRP1))) {
>> + vmcs12->pin_based_vm_exec_control =
>> + evmcs->pin_based_vm_exec_control;
>> + vmcs12->vm_exit_controls = evmcs->vm_exit_controls;
>> + vmcs12->secondary_vm_exec_control =
>> + evmcs->secondary_vm_exec_control;
>> + }
>> +
>> + if (unlikely(full || !(evmcs->hv_clean_fields &
>> + HV_VMX_ENLIGHTENED_CLEAN_FIELD_IO_BITMAP))) {
>> + vmcs12->io_bitmap_a = evmcs->io_bitmap_a;
>> + vmcs12->io_bitmap_b = evmcs->io_bitmap_b;
>> + }
>> +
>> + if (unlikely(full || !(evmcs->hv_clean_fields &
>> + HV_VMX_ENLIGHTENED_CLEAN_FIELD_MSR_BITMAP))) {
>> + vmcs12->msr_bitmap = evmcs->msr_bitmap;
>> + }
>> +
>> + if (unlikely(full || !(evmcs->hv_clean_fields &
>> + HV_VMX_ENLIGHTENED_CLEAN_FIELD_GUEST_GRP2))) {
>> + vmcs12->guest_es_base = evmcs->guest_es_base;
>> + vmcs12->guest_cs_base = evmcs->guest_cs_base;
>> + vmcs12->guest_ss_base = evmcs->guest_ss_base;
>> + vmcs12->guest_ds_base = evmcs->guest_ds_base;
>> + vmcs12->guest_fs_base = evmcs->guest_fs_base;
>> + vmcs12->guest_gs_base = evmcs->guest_gs_base;
>> + vmcs12->guest_ldtr_base = evmcs->guest_ldtr_base;
>> + vmcs12->guest_tr_base = evmcs->guest_tr_base;
>> + vmcs12->guest_gdtr_base = evmcs->guest_gdtr_base;
>> + vmcs12->guest_idtr_base = evmcs->guest_idtr_base;
>> + vmcs12->guest_es_limit = evmcs->guest_es_limit;
>> + vmcs12->guest_cs_limit = evmcs->guest_cs_limit;
>> + vmcs12->guest_ss_limit = evmcs->guest_ss_limit;
>> + vmcs12->guest_ds_limit = evmcs->guest_ds_limit;
>> + vmcs12->guest_fs_limit = evmcs->guest_fs_limit;
>> + vmcs12->guest_gs_limit = evmcs->guest_gs_limit;
>> + vmcs12->guest_ldtr_limit = evmcs->guest_ldtr_limit;
>> + vmcs12->guest_tr_limit = evmcs->guest_tr_limit;
>> + vmcs12->guest_gdtr_limit = evmcs->guest_gdtr_limit;
>> + vmcs12->guest_idtr_limit = evmcs->guest_idtr_limit;
>> + vmcs12->guest_es_ar_bytes = evmcs->guest_es_ar_bytes;
>> + vmcs12->guest_cs_ar_bytes = evmcs->guest_cs_ar_bytes;
>> + vmcs12->guest_ss_ar_bytes = evmcs->guest_ss_ar_bytes;
>> + vmcs12->guest_ds_ar_bytes = evmcs->guest_ds_ar_bytes;
>> + vmcs12->guest_fs_ar_bytes = evmcs->guest_fs_ar_bytes;
>> + vmcs12->guest_gs_ar_bytes = evmcs->guest_gs_ar_bytes;
>> + vmcs12->guest_ldtr_ar_bytes = evmcs->guest_ldtr_ar_bytes;
>> + vmcs12->guest_tr_ar_bytes = evmcs->guest_tr_ar_bytes;
>> + vmcs12->guest_es_selector = evmcs->guest_es_selector;
>> + vmcs12->guest_cs_selector = evmcs->guest_cs_selector;
>> + vmcs12->guest_ss_selector = evmcs->guest_ss_selector;
>> + vmcs12->guest_ds_selector = evmcs->guest_ds_selector;
>> + vmcs12->guest_fs_selector = evmcs->guest_fs_selector;
>> + vmcs12->guest_gs_selector = evmcs->guest_gs_selector;
>> + vmcs12->guest_ldtr_selector = evmcs->guest_ldtr_selector;
>> + vmcs12->guest_tr_selector = evmcs->guest_tr_selector;
>> + }
>> +
>> + if (unlikely(full || !(evmcs->hv_clean_fields &
>> + HV_VMX_ENLIGHTENED_CLEAN_FIELD_CONTROL_GRP2))) {
>> + vmcs12->tsc_offset = evmcs->tsc_offset;
>> + vmcs12->virtual_apic_page_addr = evmcs->virtual_apic_page_addr;
>> + vmcs12->xss_exit_bitmap = evmcs->xss_exit_bitmap;
>> + }
>> +
>> + if (unlikely(full || !(evmcs->hv_clean_fields &
>> + HV_VMX_ENLIGHTENED_CLEAN_FIELD_CRDR))) {
>> + vmcs12->cr0_guest_host_mask = evmcs->cr0_guest_host_mask;
>> + vmcs12->cr4_guest_host_mask = evmcs->cr4_guest_host_mask;
>> + vmcs12->cr0_read_shadow = evmcs->cr0_read_shadow;
>> + vmcs12->cr4_read_shadow = evmcs->cr4_read_shadow;
>> + vmcs12->guest_cr0 = evmcs->guest_cr0;
>> + vmcs12->guest_cr3 = evmcs->guest_cr3;
>> + vmcs12->guest_cr4 = evmcs->guest_cr4;
>> + vmcs12->guest_dr7 = evmcs->guest_dr7;
>> + }
>> +
>> + if (unlikely(full || !(evmcs->hv_clean_fields &
>> + HV_VMX_ENLIGHTENED_CLEAN_FIELD_HOST_POINTER))) {
>> + vmcs12->host_fs_base = evmcs->host_fs_base;
>> + vmcs12->host_gs_base = evmcs->host_gs_base;
>> + vmcs12->host_tr_base = evmcs->host_tr_base;
>> + vmcs12->host_gdtr_base = evmcs->host_gdtr_base;
>> + vmcs12->host_idtr_base = evmcs->host_idtr_base;
>> + vmcs12->host_rsp = evmcs->host_rsp;
>> + }
>> +
>> + if (unlikely(full || !(evmcs->hv_clean_fields &
>> + HV_VMX_ENLIGHTENED_CLEAN_FIELD_CONTROL_XLAT))) {
>> + vmcs12->ept_pointer = evmcs->ept_pointer;
>> + vmcs12->virtual_processor_id = evmcs->virtual_processor_id;
>> + }
>> +
>> + if (unlikely(full || !(evmcs->hv_clean_fields &
>> + HV_VMX_ENLIGHTENED_CLEAN_FIELD_GUEST_GRP1))) {
>> + vmcs12->vmcs_link_pointer = evmcs->vmcs_link_pointer;
>> + vmcs12->guest_ia32_debugctl = evmcs->guest_ia32_debugctl;
>> + vmcs12->guest_ia32_pat = evmcs->guest_ia32_pat;
>> + vmcs12->guest_ia32_efer = evmcs->guest_ia32_efer;
>> + vmcs12->guest_pdptr0 = evmcs->guest_pdptr0;
>> + vmcs12->guest_pdptr1 = evmcs->guest_pdptr1;
>> + vmcs12->guest_pdptr2 = evmcs->guest_pdptr2;
>> + vmcs12->guest_pdptr3 = evmcs->guest_pdptr3;
>> + vmcs12->guest_pending_dbg_exceptions =
>> + evmcs->guest_pending_dbg_exceptions;
>> + vmcs12->guest_sysenter_esp = evmcs->guest_sysenter_esp;
>> + vmcs12->guest_sysenter_eip = evmcs->guest_sysenter_eip;
>> + vmcs12->guest_bndcfgs = evmcs->guest_bndcfgs;
>> + vmcs12->guest_activity_state = evmcs->guest_activity_state;
>> + vmcs12->guest_sysenter_cs = evmcs->guest_sysenter_cs;
>> + }
>> +
>> + /*
>> + * Not used?
>> + * vmcs12->vm_exit_msr_store_addr = evmcs->vm_exit_msr_store_addr;
>> + * vmcs12->vm_exit_msr_load_addr = evmcs->vm_exit_msr_load_addr;
>> + * vmcs12->vm_entry_msr_load_addr = evmcs->vm_entry_msr_load_addr;
>> + * vmcs12->cr3_target_value0 = evmcs->cr3_target_value0;
>> + * vmcs12->cr3_target_value1 = evmcs->cr3_target_value1;
>> + * vmcs12->cr3_target_value2 = evmcs->cr3_target_value2;
>> + * vmcs12->cr3_target_value3 = evmcs->cr3_target_value3;
>> + * vmcs12->page_fault_error_code_mask =
>> + * evmcs->page_fault_error_code_mask;
>> + * vmcs12->page_fault_error_code_match =
>> + * evmcs->page_fault_error_code_match;
>> + * vmcs12->cr3_target_count = evmcs->cr3_target_count;
>> + * vmcs12->vm_exit_msr_store_count =
>> evmcs->vm_exit_msr_store_count;
>> + * vmcs12->vm_exit_msr_load_count = evmcs->vm_exit_msr_load_count;
>> + * vmcs12->vm_entry_msr_load_count =
>> evmcs->vm_entry_msr_load_count;
>> + */
>> +
>> + /*
>> + * Read only fields:
>> + * vmcs12->guest_physical_address = evmcs->guest_physical_address;
>> + * vmcs12->vm_instruction_error = evmcs->vm_instruction_error;
>> + * vmcs12->vm_exit_reason = evmcs->vm_exit_reason;
>> + * vmcs12->vm_exit_intr_info = evmcs->vm_exit_intr_info;
>> + * vmcs12->vm_exit_intr_error_code =
>> evmcs->vm_exit_intr_error_code;
>> + * vmcs12->idt_vectoring_info_field =
>> evmcs->idt_vectoring_info_field;
>> + * vmcs12->idt_vectoring_error_code =
>> evmcs->idt_vectoring_error_code;
>> + * vmcs12->vm_exit_instruction_len =
>> evmcs->vm_exit_instruction_len;
>> + * vmcs12->vmx_instruction_info = evmcs->vmx_instruction_info;
>> + * vmcs12->exit_qualification = evmcs->exit_qualification;
>> + * vmcs12->guest_linear_address = evmcs->guest_linear_address;
>> + *
>> + * Not present in struct vmcs12:
>> + * vmcs12->exit_io_instruction_ecx =
>> evmcs->exit_io_instruction_ecx;
>> + * vmcs12->exit_io_instruction_esi =
>> evmcs->exit_io_instruction_esi;
>> + * vmcs12->exit_io_instruction_edi =
>> evmcs->exit_io_instruction_edi;
>> + * vmcs12->exit_io_instruction_eip =
>> evmcs->exit_io_instruction_eip;
>> + */
>> +
>> + return 0;
>> +}
>> +
>> +static int copy_vmcs12_to_enlightened(struct vcpu_vmx *vmx)
>> +{
>> + struct vmcs12 *vmcs12 = vmx->nested.cached_vmcs12;
>> + struct hv_enlightened_vmcs *evmcs = vmx->nested.hv_evmcs;
>> +
>> + /*
>> + * Should not be changed by KVM:
>> + *
>> + * evmcs->host_es_selector = vmcs12->host_es_selector;
>> + * evmcs->host_cs_selector = vmcs12->host_cs_selector;
>> + * evmcs->host_ss_selector = vmcs12->host_ss_selector;
>> + * evmcs->host_ds_selector = vmcs12->host_ds_selector;
>> + * evmcs->host_fs_selector = vmcs12->host_fs_selector;
>> + * evmcs->host_gs_selector = vmcs12->host_gs_selector;
>> + * evmcs->host_tr_selector = vmcs12->host_tr_selector;
>> + * evmcs->host_ia32_pat = vmcs12->host_ia32_pat;
>> + * evmcs->host_ia32_efer = vmcs12->host_ia32_efer;
>> + * evmcs->host_cr0 = vmcs12->host_cr0;
>> + * evmcs->host_cr3 = vmcs12->host_cr3;
>> + * evmcs->host_cr4 = vmcs12->host_cr4;
>> + * evmcs->host_ia32_sysenter_esp = vmcs12->host_ia32_sysenter_esp;
>> + * evmcs->host_ia32_sysenter_eip = vmcs12->host_ia32_sysenter_eip;
>> + * evmcs->host_rip = vmcs12->host_rip;
>> + * evmcs->host_ia32_sysenter_cs = vmcs12->host_ia32_sysenter_cs;
>> + * evmcs->host_fs_base = vmcs12->host_fs_base;
>> + * evmcs->host_gs_base = vmcs12->host_gs_base;
>> + * evmcs->host_tr_base = vmcs12->host_tr_base;
>> + * evmcs->host_gdtr_base = vmcs12->host_gdtr_base;
>> + * evmcs->host_idtr_base = vmcs12->host_idtr_base;
>> + * evmcs->host_rsp = vmcs12->host_rsp;
>> + * sync_vmcs12() doesn't read these:
>> + * evmcs->io_bitmap_a = vmcs12->io_bitmap_a;
>> + * evmcs->io_bitmap_b = vmcs12->io_bitmap_b;
>> + * evmcs->msr_bitmap = vmcs12->msr_bitmap;
>> + * evmcs->ept_pointer = vmcs12->ept_pointer;
>> + * evmcs->xss_exit_bitmap = vmcs12->xss_exit_bitmap;
>> + * evmcs->vm_exit_msr_store_addr = vmcs12->vm_exit_msr_store_addr;
>> + * evmcs->vm_exit_msr_load_addr = vmcs12->vm_exit_msr_load_addr;
>> + * evmcs->vm_entry_msr_load_addr = vmcs12->vm_entry_msr_load_addr;
>> + * evmcs->cr3_target_value0 = vmcs12->cr3_target_value0;
>> + * evmcs->cr3_target_value1 = vmcs12->cr3_target_value1;
>> + * evmcs->cr3_target_value2 = vmcs12->cr3_target_value2;
>> + * evmcs->cr3_target_value3 = vmcs12->cr3_target_value3;
>> + * evmcs->tpr_threshold = vmcs12->tpr_threshold;
>> + * evmcs->virtual_processor_id = vmcs12->virtual_processor_id;
>> + * evmcs->exception_bitmap = vmcs12->exception_bitmap;
>> + * evmcs->vmcs_link_pointer = vmcs12->vmcs_link_pointer;
>> + * evmcs->pin_based_vm_exec_control =
>> vmcs12->pin_based_vm_exec_control;
>> + * evmcs->vm_exit_controls = vmcs12->vm_exit_controls;
>> + * evmcs->secondary_vm_exec_control =
>> vmcs12->secondary_vm_exec_control;
>> + * evmcs->page_fault_error_code_mask =
>> + * vmcs12->page_fault_error_code_mask;
>> + * evmcs->page_fault_error_code_match =
>> + * vmcs12->page_fault_error_code_match;
>> + * evmcs->cr3_target_count = vmcs12->cr3_target_count;
>> + * evmcs->virtual_apic_page_addr = vmcs12->virtual_apic_page_addr;
>> + * evmcs->tsc_offset = vmcs12->tsc_offset;
>> + * evmcs->guest_ia32_debugctl = vmcs12->guest_ia32_debugctl;
>> + * evmcs->cr0_guest_host_mask = vmcs12->cr0_guest_host_mask;
>> + * evmcs->cr4_guest_host_mask = vmcs12->cr4_guest_host_mask;
>> + * evmcs->cr0_read_shadow = vmcs12->cr0_read_shadow;
>> + * evmcs->cr4_read_shadow = vmcs12->cr4_read_shadow;
>> + * evmcs->vm_exit_msr_store_count =
>> vmcs12->vm_exit_msr_store_count;
>> + * evmcs->vm_exit_msr_load_count = vmcs12->vm_exit_msr_load_count;
>> + * evmcs->vm_entry_msr_load_count =
>> vmcs12->vm_entry_msr_load_count;
>> + *
>> + * Not present in struct vmcs12:
>> + * evmcs->exit_io_instruction_ecx =
>> vmcs12->exit_io_instruction_ecx;
>> + * evmcs->exit_io_instruction_esi =
>> vmcs12->exit_io_instruction_esi;
>> + * evmcs->exit_io_instruction_edi =
>> vmcs12->exit_io_instruction_edi;
>> + * evmcs->exit_io_instruction_eip =
>> vmcs12->exit_io_instruction_eip;
>> + */
>> +
>> + evmcs->guest_es_selector = vmcs12->guest_es_selector;
>> + evmcs->guest_cs_selector = vmcs12->guest_cs_selector;
>> + evmcs->guest_ss_selector = vmcs12->guest_ss_selector;
>> + evmcs->guest_ds_selector = vmcs12->guest_ds_selector;
>> + evmcs->guest_fs_selector = vmcs12->guest_fs_selector;
>> + evmcs->guest_gs_selector = vmcs12->guest_gs_selector;
>> + evmcs->guest_ldtr_selector = vmcs12->guest_ldtr_selector;
>> + evmcs->guest_tr_selector = vmcs12->guest_tr_selector;
>> +
>> + evmcs->guest_es_limit = vmcs12->guest_es_limit;
>> + evmcs->guest_cs_limit = vmcs12->guest_cs_limit;
>> + evmcs->guest_ss_limit = vmcs12->guest_ss_limit;
>> + evmcs->guest_ds_limit = vmcs12->guest_ds_limit;
>> + evmcs->guest_fs_limit = vmcs12->guest_fs_limit;
>> + evmcs->guest_gs_limit = vmcs12->guest_gs_limit;
>> + evmcs->guest_ldtr_limit = vmcs12->guest_ldtr_limit;
>> + evmcs->guest_tr_limit = vmcs12->guest_tr_limit;
>> + evmcs->guest_gdtr_limit = vmcs12->guest_gdtr_limit;
>> + evmcs->guest_idtr_limit = vmcs12->guest_idtr_limit;
>> +
>> + evmcs->guest_es_ar_bytes = vmcs12->guest_es_ar_bytes;
>> + evmcs->guest_cs_ar_bytes = vmcs12->guest_cs_ar_bytes;
>> + evmcs->guest_ss_ar_bytes = vmcs12->guest_ss_ar_bytes;
>> + evmcs->guest_ds_ar_bytes = vmcs12->guest_ds_ar_bytes;
>> + evmcs->guest_fs_ar_bytes = vmcs12->guest_fs_ar_bytes;
>> + evmcs->guest_gs_ar_bytes = vmcs12->guest_gs_ar_bytes;
>> + evmcs->guest_ldtr_ar_bytes = vmcs12->guest_ldtr_ar_bytes;
>> + evmcs->guest_tr_ar_bytes = vmcs12->guest_tr_ar_bytes;
>> +
>> + evmcs->guest_es_base = vmcs12->guest_es_base;
>> + evmcs->guest_cs_base = vmcs12->guest_cs_base;
>> + evmcs->guest_ss_base = vmcs12->guest_ss_base;
>> + evmcs->guest_ds_base = vmcs12->guest_ds_base;
>> + evmcs->guest_fs_base = vmcs12->guest_fs_base;
>> + evmcs->guest_gs_base = vmcs12->guest_gs_base;
>> + evmcs->guest_ldtr_base = vmcs12->guest_ldtr_base;
>> + evmcs->guest_tr_base = vmcs12->guest_tr_base;
>> + evmcs->guest_gdtr_base = vmcs12->guest_gdtr_base;
>> + evmcs->guest_idtr_base = vmcs12->guest_idtr_base;
>> +
>> + evmcs->guest_ia32_pat = vmcs12->guest_ia32_pat;
>> + evmcs->guest_ia32_efer = vmcs12->guest_ia32_efer;
>> +
>> + evmcs->guest_pdptr0 = vmcs12->guest_pdptr0;
>> + evmcs->guest_pdptr1 = vmcs12->guest_pdptr1;
>> + evmcs->guest_pdptr2 = vmcs12->guest_pdptr2;
>> + evmcs->guest_pdptr3 = vmcs12->guest_pdptr3;
>> +
>> + evmcs->guest_pending_dbg_exceptions =
>> + vmcs12->guest_pending_dbg_exceptions;
>> + evmcs->guest_sysenter_esp = vmcs12->guest_sysenter_esp;
>> + evmcs->guest_sysenter_eip = vmcs12->guest_sysenter_eip;
>> +
>> + evmcs->guest_activity_state = vmcs12->guest_activity_state;
>> + evmcs->guest_sysenter_cs = vmcs12->guest_sysenter_cs;
>> +
>> + evmcs->guest_cr0 = vmcs12->guest_cr0;
>> + evmcs->guest_cr3 = vmcs12->guest_cr3;
>> + evmcs->guest_cr4 = vmcs12->guest_cr4;
>> + evmcs->guest_dr7 = vmcs12->guest_dr7;
>> +
>> + evmcs->guest_physical_address = vmcs12->guest_physical_address;
>> +
>> + evmcs->vm_instruction_error = vmcs12->vm_instruction_error;
>> + evmcs->vm_exit_reason = vmcs12->vm_exit_reason;
>> + evmcs->vm_exit_intr_info = vmcs12->vm_exit_intr_info;
>> + evmcs->vm_exit_intr_error_code = vmcs12->vm_exit_intr_error_code;
>> + evmcs->idt_vectoring_info_field = vmcs12->idt_vectoring_info_field;
>> + evmcs->idt_vectoring_error_code = vmcs12->idt_vectoring_error_code;
>> + evmcs->vm_exit_instruction_len = vmcs12->vm_exit_instruction_len;
>> + evmcs->vmx_instruction_info = vmcs12->vmx_instruction_info;
>> +
>> + evmcs->exit_qualification = vmcs12->exit_qualification;
>> +
>> + evmcs->guest_linear_address = vmcs12->guest_linear_address;
>> + evmcs->guest_rsp = vmcs12->guest_rsp;
>> + evmcs->guest_rflags = vmcs12->guest_rflags;
>> +
>> + evmcs->guest_interruptibility_info =
>> + vmcs12->guest_interruptibility_info;
>> + evmcs->cpu_based_vm_exec_control =
>> vmcs12->cpu_based_vm_exec_control;
>> + evmcs->vm_entry_controls = vmcs12->vm_entry_controls;
>> + evmcs->vm_entry_intr_info_field = vmcs12->vm_entry_intr_info_field;
>> + evmcs->vm_entry_exception_error_code =
>> + vmcs12->vm_entry_exception_error_code;
>> + evmcs->vm_entry_instruction_len = vmcs12->vm_entry_instruction_len;
>> +
>> + evmcs->guest_rip = vmcs12->guest_rip;
>> +
>> + evmcs->guest_bndcfgs = vmcs12->guest_bndcfgs;
>> +
>> + return 0;
>> +}
>> +
>> /*
>> * Copy the writable VMCS shadow fields back to the VMCS12, in case
>> * they have been modified by the L1 guest. Note that the
>> "read-only"
>> @@ -8398,7 +8787,7 @@ static void set_current_vmptr(struct vcpu_vmx
>> *vmx, gpa_t vmptr)
>> SECONDARY_EXEC_SHADOW_VMCS);
>> vmcs_write64(VMCS_LINK_POINTER,
>> __pa(vmx->vmcs01.shadow_vmcs));
>> - vmx->nested.sync_shadow_vmcs = true;
>> + vmx->nested.need_vmcs12_sync = true;
>> }
>> vmx->nested.dirty_vmcs12 = true;
>> }
>> @@ -9960,9 +10349,16 @@ static void __noclone vmx_vcpu_run(struct
>> kvm_vcpu *vcpu)
>> vmcs_write32(PLE_WINDOW, vmx->ple_window);
>> }
>>
>> - if (vmx->nested.sync_shadow_vmcs) {
>> - copy_vmcs12_to_shadow(vmx);
>> - vmx->nested.sync_shadow_vmcs = false;
>> + if (vmx->nested.need_vmcs12_sync) {
>> + if (unlikely(vmx->nested.hv_evmcs)) {
>
> Why is this marked with unlikely()?
> In L1 guest use eVMCS, we will always have this as true for vmx_vcpu_run()
> after simulating VMExit from L2 to L1. You should not have here unlikely()
> just like you don't have it in new code added to nested_vmx_run().

I think I thought "eVMCS usage is rare" but I think you're right, I'll
drop this unlikely.

>
>> + copy_vmcs12_to_enlightened(vmx);
>> + /* All fields are clean */
>> + vmx->nested.hv_evmcs->hv_clean_fields |=
>> + HV_VMX_ENLIGHTENED_CLEAN_FIELD_ALL;
>> + } else {
>> + copy_vmcs12_to_shadow(vmx);
>> + }
>> + vmx->nested.need_vmcs12_sync = false;
>> }
>>
>> if (test_bit(VCPU_REGS_RSP, (unsigned long
>> *)&vcpu->arch.regs_dirty))
>> @@ -11281,7 +11677,7 @@ static int prepare_vmcs02(struct kvm_vcpu
>> *vcpu, struct vmcs12 *vmcs12,
>> struct vcpu_vmx *vmx = to_vmx(vcpu);
>> u32 exec_control, vmcs12_exec_ctrl;
>>
>> - if (vmx->nested.dirty_vmcs12) {
>> + if (vmx->nested.dirty_vmcs12 || vmx->nested.hv_evmcs) {
>> prepare_vmcs02_full(vcpu, vmcs12);
>> vmx->nested.dirty_vmcs12 = false;
>> }
>> @@ -11757,8 +12153,13 @@ static int nested_vmx_run(struct kvm_vcpu
>> *vcpu, bool launch)
>>
>> vmcs12 = get_vmcs12(vcpu);
>>
>> - if (enable_shadow_vmcs)
>> + if (vmx->nested.hv_evmcs) {
>> + copy_enlightened_to_vmcs12(vmx, vmx->nested.dirty_vmcs12);
>> + /* Enlightened VMCS doesn't have launch state */
>> + vmcs12->launch_state = !launch;
>> + } else if (enable_shadow_vmcs) {
>> copy_shadow_to_vmcs12(vmx);
>> + }
>>
>> /*
>> * The nested entry process starts with enforcing various
>> prerequisites
>> @@ -12383,8 +12784,8 @@ static void nested_vmx_vmexit(struct kvm_vcpu
>> *vcpu, u32 exit_reason,
>> */
>> kvm_make_request(KVM_REQ_APIC_PAGE_RELOAD, vcpu);
>>
>> - if (enable_shadow_vmcs && exit_reason != -1)
>> - vmx->nested.sync_shadow_vmcs = true;
>> + if ((exit_reason != -1) && (enable_shadow_vmcs ||
>> vmx->nested.hv_evmcs))
>> + vmx->nested.need_vmcs12_sync = true;
>>
>> /* in case we halted in L2 */
>> vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
>> @@ -12463,12 +12864,14 @@ static void nested_vmx_entry_failure(struct
>> kvm_vcpu *vcpu,
>> struct vmcs12 *vmcs12,
>> u32 reason, unsigned long qualification)
>> {
>> + struct vcpu_vmx *vmx = to_vmx(vcpu);
>> +
>> load_vmcs12_host_state(vcpu, vmcs12);
>> vmcs12->vm_exit_reason = reason | VMX_EXIT_REASONS_FAILED_VMENTRY;
>> vmcs12->exit_qualification = qualification;
>> nested_vmx_succeed(vcpu);
>> - if (enable_shadow_vmcs)
>> - to_vmx(vcpu)->nested.sync_shadow_vmcs = true;
>> + if (enable_shadow_vmcs || vmx->nested.hv_evmcs)
>> + vmx->nested.need_vmcs12_sync = true;
>> }
>>
>> static int vmx_check_intercept(struct kvm_vcpu *vcpu,
>> --
>> 2.14.4

--
Vitaly

2018-06-15 10:35:40

by Vitaly Kuznetsov

[permalink] [raw]

Subject: Re: [PATCH 2/5] KVM: nVMX: add KVM_CAP_HYPERV_ENLIGHTENED_VMCS capability

Liran Alon <[email protected]> writes:

> ----- [email protected] wrote:
>
>> Enlightened VMCS is opt-in. The current version does not contain all
>> fields supported by nested VMX so we must not advertise the
>> corresponding VMX features if enlightened VMCS is enabled.
>>
>> Userspace is given the enlightened VMCS version supported by KVM as
>> part of enabling KVM_CAP_HYPERV_ENLIGHTENED_VMCS. The version is to
>> be advertised to the nested hypervisor, currently done via a cpuid
>> leaf for Hyper-V.
>>
>> Suggested-by: Ladi Prosek <[email protected]>
>> Signed-off-by: Vitaly Kuznetsov <[email protected]>
>> ---
>> arch/x86/include/asm/kvm_host.h | 3 +
>> arch/x86/kvm/svm.c | 9 +++
>> arch/x86/kvm/vmx.c | 138
>> ++++++++++++++++++++++------------------
>> arch/x86/kvm/x86.c | 15 +++++
>> include/uapi/linux/kvm.h | 1 +
>> 5 files changed, 105 insertions(+), 61 deletions(-)
>>
>> diff --git a/arch/x86/include/asm/kvm_host.h
>> b/arch/x86/include/asm/kvm_host.h
>> index 0ebe659f2802..d7e8f7155d79 100644
>> --- a/arch/x86/include/asm/kvm_host.h
>> +++ b/arch/x86/include/asm/kvm_host.h
>> @@ -1095,6 +1095,9 @@ struct kvm_x86_ops {
>> int (*mem_enc_unreg_region)(struct kvm *kvm, struct kvm_enc_region
>> *argp);
>>
>> int (*get_msr_feature)(struct kvm_msr_entry *entry);
>> +
>> + int (*nested_enable_evmcs)(struct kvm_vcpu *vcpu,
>> + uint16_t *vmcs_version);
>> };
>>
>> struct kvm_arch_async_pf {
>> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
>> index d9305f1723f5..6dc42c870565 100644
>> --- a/arch/x86/kvm/svm.c
>> +++ b/arch/x86/kvm/svm.c
>> @@ -7009,6 +7009,13 @@ static int svm_unregister_enc_region(struct kvm
>> *kvm,
>> return ret;
>> }
>>
>> +static int nested_enable_evmcs(struct kvm_vcpu *vcpu,
>> + uint16_t *vmcs_version)
>> +{
>> + /* Intel-only feature */
>> + return -ENODEV;
>> +}
>> +
>> static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
>> .cpu_has_kvm_support = has_svm,
>> .disabled_by_bios = is_disabled,
>> @@ -7135,6 +7142,8 @@ static struct kvm_x86_ops svm_x86_ops
>> __ro_after_init = {
>> .mem_enc_op = svm_mem_enc_op,
>> .mem_enc_reg_region = svm_register_enc_region,
>> .mem_enc_unreg_region = svm_unregister_enc_region,
>> +
>> + .nested_enable_evmcs = nested_enable_evmcs,
>> };
>>
>> static int __init svm_init(void)
>> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
>> index 48989f78be60..51749207cef1 100644
>> --- a/arch/x86/kvm/vmx.c
>> +++ b/arch/x86/kvm/vmx.c
>> @@ -648,6 +648,13 @@ struct nested_vmx {
>>
>> bool change_vmcs01_virtual_apic_mode;
>>
>> + /*
>> + * Enlightened VMCS has been enabled. It does not mean that L1 has
>> to
>> + * use it. However, VMX features available to L1 will be limited
>> based
>> + * on what the enlightened VMCS supports.
>> + */
>> + bool enlightened_vmcs_enabled;
>> +
>> /* L2 must run next, and mustn't decide to exit to L1. */
>> bool nested_run_pending;
>>
>> @@ -1186,6 +1193,49 @@ DEFINE_STATIC_KEY_FALSE(enable_evmcs);
>>
>> #define KVM_EVMCS_VERSION 1
>>
>> +/*
>> + * Enlightened VMCSv1 doesn't support these:
>> + *
>> + * POSTED_INTR_NV = 0x00000002,
>> + * GUEST_INTR_STATUS = 0x00000810,
>> + * APIC_ACCESS_ADDR = 0x00002014,
>> + * POSTED_INTR_DESC_ADDR = 0x00002016,
>> + * EOI_EXIT_BITMAP0 = 0x0000201c,
>> + * EOI_EXIT_BITMAP1 = 0x0000201e,
>> + * EOI_EXIT_BITMAP2 = 0x00002020,
>> + * EOI_EXIT_BITMAP3 = 0x00002022,
>> + * GUEST_PML_INDEX = 0x00000812,
>> + * PML_ADDRESS = 0x0000200e,
>> + * VM_FUNCTION_CONTROL = 0x00002018,
>> + * EPTP_LIST_ADDRESS = 0x00002024,
>> + * VMREAD_BITMAP = 0x00002026,
>> + * VMWRITE_BITMAP = 0x00002028,
>> + *
>> + * TSC_MULTIPLIER = 0x00002032,
>> + * PLE_GAP = 0x00004020,
>> + * PLE_WINDOW = 0x00004022,
>> + * VMX_PREEMPTION_TIMER_VALUE = 0x0000482E,
>> + * GUEST_IA32_PERF_GLOBAL_CTRL = 0x00002808,
>> + * HOST_IA32_PERF_GLOBAL_CTRL = 0x00002c04,
>> + *
>> + * Currently unsupported in KVM:
>> + * GUEST_IA32_RTIT_CTL = 0x00002814,
>> + */
>> +#define EVMCS1_UNSUPPORTED_PINCTRL (PIN_BASED_POSTED_INTR | \
>> + PIN_BASED_VMX_PREEMPTION_TIMER)
>> +#define EVMCS1_UNSUPPORTED_2NDEXEC \
>> + (SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY | \
>> + SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES | \
>> + SECONDARY_EXEC_APIC_REGISTER_VIRT | \
>> + SECONDARY_EXEC_ENABLE_PML | \
>> + SECONDARY_EXEC_ENABLE_VMFUNC | \
>> + SECONDARY_EXEC_SHADOW_VMCS | \
>> + SECONDARY_EXEC_TSC_SCALING | \
>> + SECONDARY_EXEC_PAUSE_LOOP_EXITING)
>> +#define EVMCS1_UNSUPPORTED_VMEXIT_CTRL
>> (VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL)
>> +#define EVMCS1_UNSUPPORTED_VMENTRY_CTRL
>> (VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL)
>> +#define EVMCS1_UNSUPPORTED_VMFUNC (VMX_VMFUNC_EPTP_SWITCHING)
>> +
>> #if IS_ENABLED(CONFIG_HYPERV)
>> static bool __read_mostly enlightened_vmcs = true;
>> module_param(enlightened_vmcs, bool, 0444);
>> @@ -1278,69 +1328,12 @@ static void evmcs_load(u64 phys_addr)
>>
>> static void evmcs_sanitize_exec_ctrls(struct vmcs_config *vmcs_conf)
>> {
>> - /*
>> - * Enlightened VMCSv1 doesn't support these:
>> - *
>> - * POSTED_INTR_NV = 0x00000002,
>> - * GUEST_INTR_STATUS = 0x00000810,
>> - * APIC_ACCESS_ADDR = 0x00002014,
>> - * POSTED_INTR_DESC_ADDR = 0x00002016,
>> - * EOI_EXIT_BITMAP0 = 0x0000201c,
>> - * EOI_EXIT_BITMAP1 = 0x0000201e,
>> - * EOI_EXIT_BITMAP2 = 0x00002020,
>> - * EOI_EXIT_BITMAP3 = 0x00002022,
>> - */
>> - vmcs_conf->pin_based_exec_ctrl &= ~PIN_BASED_POSTED_INTR;
>> - vmcs_conf->cpu_based_2nd_exec_ctrl &=
>> - ~SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY;
>> - vmcs_conf->cpu_based_2nd_exec_ctrl &=
>> - ~SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES;
>> - vmcs_conf->cpu_based_2nd_exec_ctrl &=
>> - ~SECONDARY_EXEC_APIC_REGISTER_VIRT;
>> -
>> - /*
>> - * GUEST_PML_INDEX = 0x00000812,
>> - * PML_ADDRESS = 0x0000200e,
>> - */
>> - vmcs_conf->cpu_based_2nd_exec_ctrl &= ~SECONDARY_EXEC_ENABLE_PML;
>> + vmcs_conf->pin_based_exec_ctrl &= ~EVMCS1_UNSUPPORTED_PINCTRL;
>> + vmcs_conf->cpu_based_2nd_exec_ctrl &= ~EVMCS1_UNSUPPORTED_2NDEXEC;
>>
>> - /* VM_FUNCTION_CONTROL = 0x00002018, */
>> - vmcs_conf->cpu_based_2nd_exec_ctrl &=
>> ~SECONDARY_EXEC_ENABLE_VMFUNC;
>> + vmcs_conf->vmexit_ctrl &= ~EVMCS1_UNSUPPORTED_VMEXIT_CTRL;
>> + vmcs_conf->vmentry_ctrl &= ~EVMCS1_UNSUPPORTED_VMENTRY_CTRL;
>>
>> - /*
>> - * EPTP_LIST_ADDRESS = 0x00002024,
>> - * VMREAD_BITMAP = 0x00002026,
>> - * VMWRITE_BITMAP = 0x00002028,
>> - */
>> - vmcs_conf->cpu_based_2nd_exec_ctrl &= ~SECONDARY_EXEC_SHADOW_VMCS;
>> -
>> - /*
>> - * TSC_MULTIPLIER = 0x00002032,
>> - */
>> - vmcs_conf->cpu_based_2nd_exec_ctrl &= ~SECONDARY_EXEC_TSC_SCALING;
>> -
>> - /*
>> - * PLE_GAP = 0x00004020,
>> - * PLE_WINDOW = 0x00004022,
>> - */
>> - vmcs_conf->cpu_based_2nd_exec_ctrl &=
>> ~SECONDARY_EXEC_PAUSE_LOOP_EXITING;
>> -
>> - /*
>> - * VMX_PREEMPTION_TIMER_VALUE = 0x0000482E,
>> - */
>> - vmcs_conf->pin_based_exec_ctrl &= ~PIN_BASED_VMX_PREEMPTION_TIMER;
>> -
>> - /*
>> - * GUEST_IA32_PERF_GLOBAL_CTRL = 0x00002808,
>> - * HOST_IA32_PERF_GLOBAL_CTRL = 0x00002c04,
>> - */
>> - vmcs_conf->vmexit_ctrl &= ~VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL;
>> - vmcs_conf->vmentry_ctrl &= ~VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL;
>> -
>> - /*
>> - * Currently unsupported in KVM:
>> - * GUEST_IA32_RTIT_CTL = 0x00002814,
>> - */
>
> The creation of the EVMCS1_UNSUPPORTED_* macros and the refactor to evmcs_sanitize_exec_ctrls()
> should be done in a separate patch in this series before this one.
>

Sure, will do!

>> }
>> #else /* !IS_ENABLED(CONFIG_HYPERV) */
>> static inline void evmcs_write64(unsigned long field, u64 value) {}
>> @@ -1354,6 +1347,27 @@ static inline void
>> evmcs_sanitize_exec_ctrls(struct vmcs_config *vmcs_conf) {}
>> static inline void evmcs_touch_msr_bitmap(void) {}
>> #endif /* IS_ENABLED(CONFIG_HYPERV) */
>>
>> +static int nested_enable_evmcs(struct kvm_vcpu *vcpu,
>> + uint16_t *vmcs_version)
>> +{
>> + struct vcpu_vmx *vmx = to_vmx(vcpu);
>> +
>> + /* We don't support disabling the feature for simplicity. */
>> + if (vmx->nested.enlightened_vmcs_enabled)
>> + return 0;
>> +
>> + vmx->nested.enlightened_vmcs_enabled = true;
>> + *vmcs_version = (KVM_EVMCS_VERSION << 8) | 1;
>
> Please add a comment here explaining the "<< 8) | 1" part.
>

Got it.

>> +
>> + vmx->nested.msrs.pinbased_ctls_high &= ~EVMCS1_UNSUPPORTED_PINCTRL;
>> + vmx->nested.msrs.entry_ctls_high &=
>> ~EVMCS1_UNSUPPORTED_VMENTRY_CTRL;
>> + vmx->nested.msrs.exit_ctls_high &= ~EVMCS1_UNSUPPORTED_VMEXIT_CTRL;
>> + vmx->nested.msrs.secondary_ctls_high &=
>> ~EVMCS1_UNSUPPORTED_2NDEXEC;
>> + vmx->nested.msrs.vmfunc_controls &= ~EVMCS1_UNSUPPORTED_VMFUNC;
>> +
>> + return 0;
>> +}
>> +
>> static inline bool is_exception_n(u32 intr_info, u8 vector)
>> {
>> return (intr_info & (INTR_INFO_INTR_TYPE_MASK |
>> INTR_INFO_VECTOR_MASK |
>> @@ -13039,6 +13053,8 @@ static struct kvm_x86_ops vmx_x86_ops
>> __ro_after_init = {
>> .pre_enter_smm = vmx_pre_enter_smm,
>> .pre_leave_smm = vmx_pre_leave_smm,
>> .enable_smi_window = enable_smi_window,
>> +
>> + .nested_enable_evmcs = nested_enable_evmcs,
>> };
>>
>> static int __init vmx_init(void)
>> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
>> index a57766b940a5..51488019dec2 100644
>> --- a/arch/x86/kvm/x86.c
>> +++ b/arch/x86/kvm/x86.c
>> @@ -2873,6 +2873,7 @@ int kvm_vm_ioctl_check_extension(struct kvm
>> *kvm, long ext)
>> case KVM_CAP_HYPERV_VP_INDEX:
>> case KVM_CAP_HYPERV_EVENTFD:
>> case KVM_CAP_HYPERV_TLBFLUSH:
>> + case KVM_CAP_HYPERV_ENLIGHTENED_VMCS:
>> case KVM_CAP_PCI_SEGMENT:
>> case KVM_CAP_DEBUGREGS:
>> case KVM_CAP_X86_ROBUST_SINGLESTEP:
>> @@ -3650,6 +3651,10 @@ static int kvm_set_guest_paused(struct kvm_vcpu
>> *vcpu)
>> static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,
>> struct kvm_enable_cap *cap)
>> {
>> + int r;
>> + uint16_t vmcs_version;
>> + void __user *user_ptr;
>> +
>> if (cap->flags)
>> return -EINVAL;
>>
>> @@ -3662,6 +3667,16 @@ static int kvm_vcpu_ioctl_enable_cap(struct
>> kvm_vcpu *vcpu,
>> return -EINVAL;
>> return kvm_hv_activate_synic(vcpu, cap->cap ==
>> KVM_CAP_HYPERV_SYNIC2);
>> + case KVM_CAP_HYPERV_ENLIGHTENED_VMCS:
>> + r = kvm_x86_ops->nested_enable_evmcs(vcpu, &vmcs_version);
>> + if (!r) {
>> + user_ptr = (void __user *)(uintptr_t)cap->args[0];
>> + if (copy_to_user(user_ptr, &vmcs_version,
>> + sizeof(vmcs_version)))
>> + r = -EFAULT;
>> + }
>> + return r;
>> +
>> default:
>> return -EINVAL;
>> }
>> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
>> index b6270a3b38e9..5c4b79c1af19 100644
>> --- a/include/uapi/linux/kvm.h
>> +++ b/include/uapi/linux/kvm.h
>> @@ -949,6 +949,7 @@ struct kvm_ppc_resize_hpt {
>> #define KVM_CAP_GET_MSR_FEATURES 153
>> #define KVM_CAP_HYPERV_EVENTFD 154
>> #define KVM_CAP_HYPERV_TLBFLUSH 155
>> +#define KVM_CAP_HYPERV_ENLIGHTENED_VMCS 156
>>
>> #ifdef KVM_CAP_IRQ_ROUTING
>>
>> --
>> 2.14.4
>
> Besides above comments,
> Reviewed-By: Liran Alon <[email protected]>

Thank you for reviewing the series!

--
Vitaly