[PATCH v3 1/2] KVM: arm/arm64: Add vcpu ENABLE_CAP functionality

Alexander Graf
2016-09-16T06:26:26Z

In a follow-up patch we will need to enable capabilities on demand for
backwards compatibility. This patch adds the generic framework to handle
vcpu cap enablement to the arm code base.

Signed-off-by: Alexander Graf <agraf@suse.de>
---
Documentation/virtual/kvm/api.txt | 4 +++-
arch/arm/kvm/arm.c | 25 +++++++++++++++++++++++++
2 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 739db9a..23937e0 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -997,7 +997,9 @@ documentation when it pops into existence).

Capability: KVM_CAP_ENABLE_CAP, KVM_CAP_ENABLE_CAP_VM
Architectures: x86 (only KVM_CAP_ENABLE_CAP_VM),
- mips (only KVM_CAP_ENABLE_CAP), ppc, s390
+ mips (only KVM_CAP_ENABLE_CAP), ppc, s390,
+ arm (only KVM_CAP_ENABLE_CAP),
+ arm64 (only KVM_CAP_ENABLE_CAP)
Type: vcpu ioctl, vm ioctl (with KVM_CAP_ENABLE_CAP_VM)
Parameters: struct kvm_enable_cap (in)
Returns: 0 on success; -1 on error
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 75f130e..c84b6ad 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -878,6 +878,23 @@ static int kvm_arm_vcpu_has_attr(struct kvm_vcpu *vcpu,
return ret;
}

+static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,
+ struct kvm_enable_cap *cap)
+{
+ int r;
+
+ if (cap->flags)
+ return -EINVAL;
+
+ switch (cap->cap) {
+ default:
+ r = -EINVAL;
+ break;
+ }
+
+ return r;
+}
+
long kvm_arch_vcpu_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg)
{
@@ -941,6 +958,14 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
return -EFAULT;
return kvm_arm_vcpu_has_attr(vcpu, &attr);
}
+ case KVM_ENABLE_CAP:
+ {
+ struct kvm_enable_cap cap;
+
+ if (copy_from_user(&cap, argp, sizeof(cap)))
+ return -EFAULT;
+ return kvm_vcpu_ioctl_enable_cap(vcpu, &cap);
+ }
default:
return -EINVAL;
}
--
2.6.6