Some times we don't want all capabilities to be available to all
our vcpus. One example for that is the OSI interface, implemented
in the next patch.
In order to have a generic mechanism in how to enable capabilities
individually, this patch introduces a new ioctl that can be used
for this purpose. That way features we don't want in all guests or
userspace configurations can just not be enabled and we're good.
Signed-off-by: Alexander Graf <agraf@xxxxxxx>
---
arch/powerpc/kvm/powerpc.c | 23 +++++++++++++++++++++++
include/linux/kvm.h | 8 ++++++++
2 files changed, 31 insertions(+), 0 deletions(-)
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index a28a512..f52752c 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -462,6 +462,20 @@ int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu, struct kvm_interrupt *irq)
return 0;
}
+static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,
+ struct kvm_enable_cap *cap)
+{
+ int r;
+
+ switch (cap->cap) {
+ default:
+ r = -EINVAL;
+ break;
+ }
+
+ return r;
+}
+
int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
struct kvm_mp_state *mp_state)
{
@@ -490,6 +504,15 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
r = kvm_vcpu_ioctl_interrupt(vcpu, &irq);
break;
}
+ case KVM_ENABLE_CAP:
+ {
+ struct kvm_enable_cap cap;
+ r = -EFAULT;
+ if (copy_from_user(&cap, argp, sizeof(cap)))
+ goto out;
+ r = kvm_vcpu_ioctl_enable_cap(vcpu, &cap);
+ break;
+ }
default:
r = -EINVAL;
}
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index ce28767..c7ed3cb 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -400,6 +400,12 @@ struct kvm_ioeventfd {
__u8 pad[36];
};
+/* for KVM_ENABLE_CAP */
+struct kvm_enable_cap {
+ /* in */
+ __u32 cap;
+};
+
#define KVMIO 0xAE
/*
@@ -696,6 +702,8 @@ struct kvm_clock_data {
/* Available with KVM_CAP_DEBUGREGS */
#define KVM_GET_DEBUGREGS _IOR(KVMIO, 0xa1, struct kvm_debugregs)
#define KVM_SET_DEBUGREGS _IOW(KVMIO, 0xa2, struct kvm_debugregs)
+/* No need for CAP, because then it just always fails */
+#define KVM_ENABLE_CAP _IOW(KVMIO, 0xa3, struct kvm_enable_cap)
#define KVM_DEV_ASSIGN_ENABLE_IOMMU (1 << 0)
--
1.6.0.2
--
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