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| author | Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> | 2012-02-07 23:19:20 +0530 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2012-03-08 14:10:11 +0200 |
| commit | 10166744b80a41c30d82bc6e11140f5b28d257ab (patch) | |
| tree | 53b362f77d16ed91d8ecf373f7106fde12027ab7 /arch/x86/kvm/vmx.c | |
| parent | e26101b116a6235bcd80b3a4c38c9fe91286cd79 (diff) | |
| download | lwn-10166744b80a41c30d82bc6e11140f5b28d257ab.tar.gz lwn-10166744b80a41c30d82bc6e11140f5b28d257ab.zip | |
KVM: VMX: remove yield_on_hlt
yield_on_hlt was introduced for CPU bandwidth capping. Now it is
redundant with CFS hardlimit.
yield_on_hlt also complicates the scenario in paravirtual environment,
that needs to trap halt. for e.g. paravirtualized ticket spinlocks.
Acked-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'arch/x86/kvm/vmx.c')
| -rw-r--r-- | arch/x86/kvm/vmx.c | 22 |
1 files changed, 1 insertions, 21 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 575fb742a6fc..d2bd719925a6 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -70,9 +70,6 @@ module_param(emulate_invalid_guest_state, bool, S_IRUGO); static bool __read_mostly vmm_exclusive = 1; module_param(vmm_exclusive, bool, S_IRUGO); -static bool __read_mostly yield_on_hlt = 1; -module_param(yield_on_hlt, bool, S_IRUGO); - static bool __read_mostly fasteoi = 1; module_param(fasteoi, bool, S_IRUGO); @@ -1655,17 +1652,6 @@ static void skip_emulated_instruction(struct kvm_vcpu *vcpu) vmx_set_interrupt_shadow(vcpu, 0); } -static void vmx_clear_hlt(struct kvm_vcpu *vcpu) -{ - /* Ensure that we clear the HLT state in the VMCS. We don't need to - * explicitly skip the instruction because if the HLT state is set, then - * the instruction is already executing and RIP has already been - * advanced. */ - if (!yield_on_hlt && - vmcs_read32(GUEST_ACTIVITY_STATE) == GUEST_ACTIVITY_HLT) - vmcs_write32(GUEST_ACTIVITY_STATE, GUEST_ACTIVITY_ACTIVE); -} - /* * KVM wants to inject page-faults which it got to the guest. This function * checks whether in a nested guest, we need to inject them to L1 or L2. @@ -1718,7 +1704,6 @@ static void vmx_queue_exception(struct kvm_vcpu *vcpu, unsigned nr, intr_info |= INTR_TYPE_HARD_EXCEPTION; vmcs_write32(VM_ENTRY_INTR_INFO_FIELD, intr_info); - vmx_clear_hlt(vcpu); } static bool vmx_rdtscp_supported(void) @@ -2405,7 +2390,7 @@ static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf) &_pin_based_exec_control) < 0) return -EIO; - min = + min = CPU_BASED_HLT_EXITING | #ifdef CONFIG_X86_64 CPU_BASED_CR8_LOAD_EXITING | CPU_BASED_CR8_STORE_EXITING | @@ -2420,9 +2405,6 @@ static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf) CPU_BASED_INVLPG_EXITING | CPU_BASED_RDPMC_EXITING; - if (yield_on_hlt) - min |= CPU_BASED_HLT_EXITING; - opt = CPU_BASED_TPR_SHADOW | CPU_BASED_USE_MSR_BITMAPS | CPU_BASED_ACTIVATE_SECONDARY_CONTROLS; @@ -4009,7 +3991,6 @@ static void vmx_inject_irq(struct kvm_vcpu *vcpu) } else intr |= INTR_TYPE_EXT_INTR; vmcs_write32(VM_ENTRY_INTR_INFO_FIELD, intr); - vmx_clear_hlt(vcpu); } static void vmx_inject_nmi(struct kvm_vcpu *vcpu) @@ -4041,7 +4022,6 @@ static void vmx_inject_nmi(struct kvm_vcpu *vcpu) } vmcs_write32(VM_ENTRY_INTR_INFO_FIELD, INTR_TYPE_NMI_INTR | INTR_INFO_VALID_MASK | NMI_VECTOR); - vmx_clear_hlt(vcpu); } static int vmx_nmi_allowed(struct kvm_vcpu *vcpu) |