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KVM: VMX: remove yield_on_hlt

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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>
This commit is contained in:
Raghavendra K T 2012-02-07 23:19:20 +05:30 committed by Avi Kivity
parent e26101b116
commit 10166744b8
1 changed files with 1 additions and 21 deletions
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22
arch/x86/kvm/vmx.c
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@ -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)