Re: [RFC PATCH v2 04/11] KVM: VMX: Add IA32_SPEC_CTRL virtualization support

[Chao Gao]

On Mon, Apr 17, 2023 at 02:48:56PM +0800, Chenyi Qiang wrote:
>> Co-developed-by: Chao Gao <chao.gao@xxxxxxxxx>
>> Signed-off-by: Chao Gao <chao.gao@xxxxxxxxx>
>> Signed-off-by: Zhang Chen <chen.zhang@xxxxxxxxx>
>> Signed-off-by: Chao Gao <chao.gao@xxxxxxxxx>
>
>Duplicated SOB. Move the Co-developed-by down like other patches.
>

OK. Will do

>> Tested-by: Jiaan Lu <jiaan.lu@xxxxxxxxx>
>> ---
>>  arch/x86/include/asm/vmx.h         |  5 ++++
>>  arch/x86/include/asm/vmxfeatures.h |  2 ++
>>  arch/x86/kvm/vmx/capabilities.h    |  5 ++++
>>  arch/x86/kvm/vmx/nested.c          | 13 ++++++++++
>>  arch/x86/kvm/vmx/vmcs.h            |  2 ++
>>  arch/x86/kvm/vmx/vmx.c             | 34 ++++++++++++++++++++-----
>>  arch/x86/kvm/vmx/vmx.h             | 40 +++++++++++++++++++++++++++++-
>>  7 files changed, 94 insertions(+), 7 deletions(-)
>> 
>> diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h
>> index 498dc600bd5c..b9f88ecf20c3 100644
>> --- a/arch/x86/include/asm/vmx.h
>> +++ b/arch/x86/include/asm/vmx.h
>> @@ -81,6 +81,7 @@
>>   * Definitions of Tertiary Processor-Based VM-Execution Controls.
>>   */
>>  #define TERTIARY_EXEC_IPI_VIRT			VMCS_CONTROL_BIT(IPI_VIRT)
>> +#define TERTIARY_EXEC_SPEC_CTRL_VIRT		VMCS_CONTROL_BIT(SPEC_CTRL_VIRT)
>>  
>>  #define PIN_BASED_EXT_INTR_MASK                 VMCS_CONTROL_BIT(INTR_EXITING)
>>  #define PIN_BASED_NMI_EXITING                   VMCS_CONTROL_BIT(NMI_EXITING)
>> @@ -233,6 +234,10 @@ enum vmcs_field {
>>  	TERTIARY_VM_EXEC_CONTROL_HIGH	= 0x00002035,
>>  	PID_POINTER_TABLE		= 0x00002042,
>>  	PID_POINTER_TABLE_HIGH		= 0x00002043,
>> +	IA32_SPEC_CTRL_MASK             = 0x0000204A,
>> +	IA32_SPEC_CTRL_MASK_HIGH        = 0x0000204B,
>> +	IA32_SPEC_CTRL_SHADOW           = 0x0000204C,
>> +	IA32_SPEC_CTRL_SHADOW_HIGH      = 0x0000204D,
>>  	GUEST_PHYSICAL_ADDRESS          = 0x00002400,
>>  	GUEST_PHYSICAL_ADDRESS_HIGH     = 0x00002401,
>>  	VMCS_LINK_POINTER               = 0x00002800,
>> diff --git a/arch/x86/include/asm/vmxfeatures.h b/arch/x86/include/asm/vmxfeatures.h
>> index c6a7eed03914..c70d0769b7d0 100644
>> --- a/arch/x86/include/asm/vmxfeatures.h
>> +++ b/arch/x86/include/asm/vmxfeatures.h
>> @@ -89,4 +89,6 @@
>>  
>>  /* Tertiary Processor-Based VM-Execution Controls, word 3 */
>>  #define VMX_FEATURE_IPI_VIRT		( 3*32+  4) /* Enable IPI virtualization */
>> +#define VMX_FEATURE_SPEC_CTRL_VIRT	( 3*32+  7) /* Enable IA32_SPEC_CTRL virtualization */
>> +
>>  #endif /* _ASM_X86_VMXFEATURES_H */
>> diff --git a/arch/x86/kvm/vmx/capabilities.h b/arch/x86/kvm/vmx/capabilities.h
>> index 45162c1bcd8f..a7ab70b55acf 100644
>> --- a/arch/x86/kvm/vmx/capabilities.h
>> +++ b/arch/x86/kvm/vmx/capabilities.h
>> @@ -138,6 +138,11 @@ static inline bool cpu_has_tertiary_exec_ctrls(void)
>>  		CPU_BASED_ACTIVATE_TERTIARY_CONTROLS;
>>  }
>>  
>> +static __always_inline bool cpu_has_spec_ctrl_virt(void)
>
>Do we need to use __always_inline to force generating inline code? or
>just align with other cpu_has_xxx() functions, use inline annotation.

__always_inline is needed because this function is called from 
vmx_spec_ctrl_restore_host() which is in .noinstr section. With just
__inline, the objtool may complain:

vmlinux.o: warning: objtool: vmx_spec_ctrl_restore_host+0xb3: call to cpu_has_spec_ctrl_virt() leaves .noinstr.text section

>
>> +{
>> +	return vmcs_config.cpu_based_3rd_exec_ctrl & TERTIARY_EXEC_SPEC_CTRL_VIRT;
>> +}
>> +
>>  static inline bool cpu_has_vmx_virtualize_apic_accesses(void)
>>  {
>>  	return vmcs_config.cpu_based_2nd_exec_ctrl &
>