On 2013-09-16 07:42, Arthur Chunqi Li wrote:
> On Sat, Sep 14, 2013 at 1:15 AM, Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote:
>> Il 06/09/2013 04:04, Arthur Chunqi Li ha scritto:
>>> This patch contains the following two changes:
>>> 1. Fix the bug in nested preemption timer support. If vmexit L2->L0
>>> with some reasons not emulated by L1, preemption timer value should
>>> be save in such exits.
>>> 2. Add support of "Save VMX-preemption timer value" VM-Exit controls
>>> to nVMX.
>>>
>>> With this patch, nested VMX preemption timer features are fully
>>> supported.
>>>
>>> Signed-off-by: Arthur Chunqi Li <yzt356@xxxxxxxxx>
>>> ---
>>> ChangeLog to v3:
>>> Move nested_adjust_preemption_timer to the latest place just before vmenter.
>>> Some minor changes.
>>>
>>> arch/x86/include/uapi/asm/msr-index.h | 1 +
>>> arch/x86/kvm/vmx.c | 49 +++++++++++++++++++++++++++++++--
>>> 2 files changed, 48 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/arch/x86/include/uapi/asm/msr-index.h b/arch/x86/include/uapi/asm/msr-index.h
>>> index bb04650..b93e09a 100644
>>> --- a/arch/x86/include/uapi/asm/msr-index.h
>>> +++ b/arch/x86/include/uapi/asm/msr-index.h
>>> @@ -536,6 +536,7 @@
>>>
>>> /* MSR_IA32_VMX_MISC bits */
>>> #define MSR_IA32_VMX_MISC_VMWRITE_SHADOW_RO_FIELDS (1ULL << 29)
>>> +#define MSR_IA32_VMX_MISC_PREEMPTION_TIMER_SCALE 0x1F
>>> /* AMD-V MSRs */
>>>
>>> #define MSR_VM_CR 0xc0010114
>>> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
>>> index 1f1da43..f364d16 100644
>>> --- a/arch/x86/kvm/vmx.c
>>> +++ b/arch/x86/kvm/vmx.c
>>> @@ -374,6 +374,8 @@ struct nested_vmx {
>>> */
>>> struct page *apic_access_page;
>>> u64 msr_ia32_feature_control;
>>> + /* Set if vmexit is L2->L1 */
>>> + bool nested_vmx_exit;
>>> };
>>>
>>> #define POSTED_INTR_ON 0
>>> @@ -2204,7 +2206,17 @@ static __init void nested_vmx_setup_ctls_msrs(void)
>>> #ifdef CONFIG_X86_64
>>> VM_EXIT_HOST_ADDR_SPACE_SIZE |
>>> #endif
>>> - VM_EXIT_LOAD_IA32_PAT | VM_EXIT_SAVE_IA32_PAT;
>>> + VM_EXIT_LOAD_IA32_PAT | VM_EXIT_SAVE_IA32_PAT |
>>> + VM_EXIT_SAVE_VMX_PREEMPTION_TIMER;
>>> + if (!(nested_vmx_pinbased_ctls_high &
>>> + PIN_BASED_VMX_PREEMPTION_TIMER) ||
>>> + !(nested_vmx_exit_ctls_high &
>>> + VM_EXIT_SAVE_VMX_PREEMPTION_TIMER)) {
>>
>> Align this under the other "!". Also, I prefer to have one long line
>> for the whole "!(... & ...) ||" (and likewise below), but I don't know
>> if Gleb agrees
>>
>>> + nested_vmx_exit_ctls_high &=
>>> + (~VM_EXIT_SAVE_VMX_PREEMPTION_TIMER);
>>
>> Please remove parentheses around ~VM_EXIT_SAVE_VMX_PREEMPTION_TIMER, and
>> likewise elsewhere in the patch.
>>
>>> + nested_vmx_pinbased_ctls_high &=
>>> + (~PIN_BASED_VMX_PREEMPTION_TIMER);
>>> + }
>>> nested_vmx_exit_ctls_high |= (VM_EXIT_ALWAYSON_WITHOUT_TRUE_MSR |
>>> VM_EXIT_LOAD_IA32_EFER);
>>>
>>> @@ -6707,6 +6719,24 @@ static void vmx_get_exit_info(struct kvm_vcpu *vcpu, u64 *info1, u64 *info2)
>>> *info2 = vmcs_read32(VM_EXIT_INTR_INFO);
>>> }
>>>
>>> +static void nested_adjust_preemption_timer(struct kvm_vcpu *vcpu)
>>> +{
>>> + u64 delta_tsc_l1;
>>> + u32 preempt_val_l1, preempt_val_l2, preempt_scale;
>>
>> Should this exit immediately if the preemption timer pin-based control
>> is disabled?
> Hi Paolo,
> How can I get pin-based control here from "struct kvm_vcpu *vcpu"?
You can find get_vmcs12(vcpu)->pin_based_vm_exec_control in existing code.
Jan
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