Re: [v2 04/11] vmx: add PML definition and feature detection.

[Kai Huang <kai.huang@linux.intel.com>]

On 04/17/2015 06:35 AM, Tian, Kevin wrote:
>> From: Kai Huang [mailto:kai.huang@linux.intel.com]
>> Sent: Wednesday, April 15, 2015 3:04 PM
>>
>> The patch adds PML definition and feature detection. Note PML won't be
>> detected
>> if PML is disabled from boot parameter. PML is also disabled in
>> construct_vmcs,
>> as it will only be enabled when domain is switched to log dirty mode.
>>
>> Signed-off-by: Kai Huang <kai.huang@linux.intel.com>
>> ---
>>   xen/arch/x86/hvm/vmx/vmcs.c        | 22 ++++++++++++++++++++++
>>   xen/include/asm-x86/hvm/vmx/vmcs.h |  6 ++++++
>>   xen/include/asm-x86/hvm/vmx/vmx.h  |  1 +
>>   3 files changed, 29 insertions(+)
>>
>> diff --git a/xen/arch/x86/hvm/vmx/vmcs.c b/xen/arch/x86/hvm/vmx/vmcs.c
>> index 4fff46d..d120370 100644
>> --- a/xen/arch/x86/hvm/vmx/vmcs.c
>> +++ b/xen/arch/x86/hvm/vmx/vmcs.c
>> @@ -141,6 +141,7 @@ static void __init vmx_display_features(void)
>>       P(cpu_has_vmx_virtual_intr_delivery, "Virtual Interrupt Delivery");
>>       P(cpu_has_vmx_posted_intr_processing, "Posted Interrupt Processing");
>>       P(cpu_has_vmx_vmcs_shadowing, "VMCS shadowing");
>> +    P(cpu_has_vmx_pml, "Page Modification Logging");
>>   #undef P
>>
>>       if ( !printed )
>> @@ -238,6 +239,8 @@ static int vmx_init_vmcs_config(void)
>>               opt |= SECONDARY_EXEC_ENABLE_VPID;
>>           if ( opt_unrestricted_guest_enabled )
>>               opt |= SECONDARY_EXEC_UNRESTRICTED_GUEST;
>> +        if ( opt_pml_enabled )
>> +            opt |= SECONDARY_EXEC_ENABLE_PML;
>>
>>           /*
>>            * "APIC Register Virtualization" and "Virtual Interrupt Delivery"
>> @@ -284,6 +287,14 @@ static int vmx_init_vmcs_config(void)
>>            */
>>           if ( !(_vmx_ept_vpid_cap & VMX_VPID_INVVPID_ALL_CONTEXT) )
>>               _vmx_secondary_exec_control &=
>> ~SECONDARY_EXEC_ENABLE_VPID;
>> +
>> +        /*
>> +         * PML cannot be supported if EPT A/D bits is not supported.
>> Actually,
>> +         * PML should not be detected if EPT A/D bits is not supported, but
>> for
>> +         * sure we do the check anyway.
>> +         */
>> +        if ( !(_vmx_ept_vpid_cap & VMX_EPT_AD_BIT) )
>> +            _vmx_secondary_exec_control &=
>> ~SECONDARY_EXEC_ENABLE_PML;
>>       }
> the comment is not very clear. I think you just want to say "EPT A/D bit is
> required for PML" or no comment at all.
Sure, I'll change it to "EPT A/D bit is required for PML".

Thanks,
-Kai
>
>>       if ( _vmx_secondary_exec_control & SECONDARY_EXEC_ENABLE_EPT )
>> @@ -304,6 +315,14 @@ static int vmx_init_vmcs_config(void)
>>                     SECONDARY_EXEC_UNRESTRICTED_GUEST);
>>       }
>>
>> +    /* PML cannot be supported if EPT is not used */
>> +    if ( !(_vmx_secondary_exec_control &
>> SECONDARY_EXEC_ENABLE_EPT) )
>> +        _vmx_secondary_exec_control &=
>> ~SECONDARY_EXEC_ENABLE_PML;
>> +
>> +    /* Turn off opt_pml_enabled if PML feature is not present */
>> +    if ( !(_vmx_secondary_exec_control &
>> SECONDARY_EXEC_ENABLE_PML) )
>> +        opt_pml_enabled = 0;
>> +
>>       if ( (_vmx_secondary_exec_control &
>> SECONDARY_EXEC_PAUSE_LOOP_EXITING) &&
>>             ple_gap == 0 )
>>       {
>> @@ -1039,6 +1058,9 @@ static int construct_vmcs(struct vcpu *v)
>>           __vmwrite(POSTED_INTR_NOTIFICATION_VECTOR,
>> posted_intr_vector);
>>       }
>>
>> +    /* Disable PML anyway here as it will only be enabled in log dirty mode
>> */
>> +    v->arch.hvm_vmx.secondary_exec_control &=
>> ~SECONDARY_EXEC_ENABLE_PML;
>> +
>>       /* Host data selectors. */
>>       __vmwrite(HOST_SS_SELECTOR, __HYPERVISOR_DS);
>>       __vmwrite(HOST_DS_SELECTOR, __HYPERVISOR_DS);
>> diff --git a/xen/include/asm-x86/hvm/vmx/vmcs.h
>> b/xen/include/asm-x86/hvm/vmx/vmcs.h
>> index 6fce6aa..f831a78 100644
>> --- a/xen/include/asm-x86/hvm/vmx/vmcs.h
>> +++ b/xen/include/asm-x86/hvm/vmx/vmcs.h
>> @@ -215,6 +215,7 @@ extern u32 vmx_vmentry_control;
>>   #define SECONDARY_EXEC_ENABLE_INVPCID           0x00001000
>>   #define SECONDARY_EXEC_ENABLE_VMFUNC            0x00002000
>>   #define SECONDARY_EXEC_ENABLE_VMCS_SHADOWING    0x00004000
>> +#define SECONDARY_EXEC_ENABLE_PML               0x00020000
>>   extern u32 vmx_secondary_exec_control;
>>
>>   #define VMX_EPT_EXEC_ONLY_SUPPORTED             0x00000001
>> @@ -226,6 +227,7 @@ extern u32 vmx_secondary_exec_control;
>>   #define VMX_EPT_INVEPT_INSTRUCTION              0x00100000
>>   #define VMX_EPT_INVEPT_SINGLE_CONTEXT           0x02000000
>>   #define VMX_EPT_INVEPT_ALL_CONTEXT              0x04000000
>> +#define VMX_EPT_AD_BIT                          0x00200000
>>
>>   #define VMX_MISC_VMWRITE_ALL                    0x20000000
>>
>> @@ -274,6 +276,8 @@ extern u32 vmx_secondary_exec_control;
>>       (vmx_pin_based_exec_control & PIN_BASED_POSTED_INTERRUPT)
>>   #define cpu_has_vmx_vmcs_shadowing \
>>       (vmx_secondary_exec_control &
>> SECONDARY_EXEC_ENABLE_VMCS_SHADOWING)
>> +#define cpu_has_vmx_pml \
>> +    (vmx_secondary_exec_control & SECONDARY_EXEC_ENABLE_PML)
>>
>>   #define VMCS_RID_TYPE_MASK              0x80000000
>>
>> @@ -318,6 +322,7 @@ enum vmcs_field {
>>       GUEST_LDTR_SELECTOR             = 0x0000080c,
>>       GUEST_TR_SELECTOR               = 0x0000080e,
>>       GUEST_INTR_STATUS               = 0x00000810,
>> +    GUEST_PML_INDEX                 = 0x00000812,
>>       HOST_ES_SELECTOR                = 0x00000c00,
>>       HOST_CS_SELECTOR                = 0x00000c02,
>>       HOST_SS_SELECTOR                = 0x00000c04,
>> @@ -331,6 +336,7 @@ enum vmcs_field {
>>       VM_EXIT_MSR_STORE_ADDR          = 0x00002006,
>>       VM_EXIT_MSR_LOAD_ADDR           = 0x00002008,
>>       VM_ENTRY_MSR_LOAD_ADDR          = 0x0000200a,
>> +    PML_ADDRESS                     = 0x0000200e,
>>       TSC_OFFSET                      = 0x00002010,
>>       VIRTUAL_APIC_PAGE_ADDR          = 0x00002012,
>>       APIC_ACCESS_ADDR                = 0x00002014,
>> diff --git a/xen/include/asm-x86/hvm/vmx/vmx.h
>> b/xen/include/asm-x86/hvm/vmx/vmx.h
>> index 91c5e18..50f1bfc 100644
>> --- a/xen/include/asm-x86/hvm/vmx/vmx.h
>> +++ b/xen/include/asm-x86/hvm/vmx/vmx.h
>> @@ -185,6 +185,7 @@ static inline unsigned long pi_get_pir(struct pi_desc
>> *pi_desc, int group)
>>   #define EXIT_REASON_XSETBV              55
>>   #define EXIT_REASON_APIC_WRITE          56
>>   #define EXIT_REASON_INVPCID             58
>> +#define EXIT_REASON_PML_FULL            62
>>
>>   /*
>>    * Interruption-information format
>> --
>> 2.1.0
>
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