[PATCH 1/3] KVM: add valid_vcpu() helper

From: Avi Kivity
Date: Wed Dec 13 2006 - 08:15:26 EST


From: James Morris <jmorris@xxxxxxxxx>

Consolidate the logic for checking whether a vcpu index is valid. Also,
use likely(), as a valid value should be the overwhelmingly common case.

Signed-off-by: James Morris <jmorris@xxxxxxxxx>
Signed-off-by: Avi Kivity <avi@xxxxxxxxxxxx>

Index: linux-2.6/drivers/kvm/kvm_main.c
===================================================================
--- linux-2.6.orig/drivers/kvm/kvm_main.c
+++ linux-2.6/drivers/kvm/kvm_main.c
@@ -113,6 +113,11 @@ unsigned long segment_base(u16 selector)
}
EXPORT_SYMBOL_GPL(segment_base);

+static inline int valid_vcpu(int n)
+{
+ return likely(n >= 0 && n < KVM_MAX_VCPUS);
+}
+
int kvm_read_guest(struct kvm_vcpu *vcpu,
gva_t addr,
unsigned long size,
@@ -494,7 +499,7 @@ static int kvm_dev_ioctl_create_vcpu(str
struct kvm_vcpu *vcpu;

r = -EINVAL;
- if (n < 0 || n >= KVM_MAX_VCPUS)
+ if (!valid_vcpu(n))
goto out;

vcpu = &kvm->vcpus[n];
@@ -1179,7 +1184,7 @@ static int kvm_dev_ioctl_run(struct kvm
struct kvm_vcpu *vcpu;
int r;

- if (kvm_run->vcpu < 0 || kvm_run->vcpu >= KVM_MAX_VCPUS)
+ if (!valid_vcpu(kvm_run->vcpu))
return -EINVAL;

vcpu = vcpu_load(kvm, kvm_run->vcpu);
@@ -1208,7 +1213,7 @@ static int kvm_dev_ioctl_get_regs(struct
{
struct kvm_vcpu *vcpu;

- if (regs->vcpu < 0 || regs->vcpu >= KVM_MAX_VCPUS)
+ if (!valid_vcpu(regs->vcpu))
return -EINVAL;

vcpu = vcpu_load(kvm, regs->vcpu);
@@ -1254,7 +1259,7 @@ static int kvm_dev_ioctl_set_regs(struct
{
struct kvm_vcpu *vcpu;

- if (regs->vcpu < 0 || regs->vcpu >= KVM_MAX_VCPUS)
+ if (!valid_vcpu(regs->vcpu))
return -EINVAL;

vcpu = vcpu_load(kvm, regs->vcpu);
@@ -1301,7 +1306,7 @@ static int kvm_dev_ioctl_get_sregs(struc
struct kvm_vcpu *vcpu;
struct descriptor_table dt;

- if (sregs->vcpu < 0 || sregs->vcpu >= KVM_MAX_VCPUS)
+ if (!valid_vcpu(sregs->vcpu))
return -EINVAL;
vcpu = vcpu_load(kvm, sregs->vcpu);
if (!vcpu)
@@ -1353,7 +1358,7 @@ static int kvm_dev_ioctl_set_sregs(struc
int i;
struct descriptor_table dt;

- if (sregs->vcpu < 0 || sregs->vcpu >= KVM_MAX_VCPUS)
+ if (!valid_vcpu(sregs->vcpu))
return -EINVAL;
vcpu = vcpu_load(kvm, sregs->vcpu);
if (!vcpu)
@@ -1444,7 +1449,7 @@ static int __msr_io(struct kvm *kvm, str
struct kvm_vcpu *vcpu;
int i;

- if (msrs->vcpu < 0 || msrs->vcpu >= KVM_MAX_VCPUS)
+ if (!valid_vcpu(msrs->vcpu))
return -EINVAL;

vcpu = vcpu_load(kvm, msrs->vcpu);
@@ -1537,7 +1542,7 @@ static int kvm_dev_ioctl_interrupt(struc
{
struct kvm_vcpu *vcpu;

- if (irq->vcpu < 0 || irq->vcpu >= KVM_MAX_VCPUS)
+ if (!valid_vcpu(irq->vcpu))
return -EINVAL;
if (irq->irq < 0 || irq->irq >= 256)
return -EINVAL;
@@ -1559,7 +1564,7 @@ static int kvm_dev_ioctl_debug_guest(str
struct kvm_vcpu *vcpu;
int r;

- if (dbg->vcpu < 0 || dbg->vcpu >= KVM_MAX_VCPUS)
+ if (!valid_vcpu(dbg->vcpu))
return -EINVAL;
vcpu = vcpu_load(kvm, dbg->vcpu);
if (!vcpu)
-
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