Before virt machine or vcpu is created, vmm need check supported
features from KVM. Here ioctl command KVM_HAS_DEVICE_ATTR is added
for VM, and macro KVM_LOONGARCH_VM_FEAT_CTRL is added to check
supported feature.
Three sub-features relative with LBT are added, in later any new
feature can be added if it is used for vmm. The sub-features is
KVM_LOONGARCH_VM_FEAT_X86BT
KVM_LOONGARCH_VM_FEAT_ARMBT
KVM_LOONGARCH_VM_FEAT_MIPSBT
Signed-off-by: Bibo Mao <maobibo@xxxxxxxxxxx>
---
arch/loongarch/include/uapi/asm/kvm.h | 6 ++++
arch/loongarch/kvm/vm.c | 44 ++++++++++++++++++++++++++-
2 files changed, 49 insertions(+), 1 deletion(-)
diff --git a/arch/loongarch/include/uapi/asm/kvm.h b/arch/loongarch/include/uapi/asm/kvm.h
index 656aa6a723a6..ed12e509815c 100644
--- a/arch/loongarch/include/uapi/asm/kvm.h
+++ b/arch/loongarch/include/uapi/asm/kvm.h
@@ -91,6 +91,12 @@ struct kvm_fpu {
#define KVM_IOC_CSRID(REG) LOONGARCH_REG_64(KVM_REG_LOONGARCH_CSR, REG)
#define KVM_IOC_CPUCFG(REG) LOONGARCH_REG_64(KVM_REG_LOONGARCH_CPUCFG, REG)
+/* Device Control API on vm fd */
+#define KVM_LOONGARCH_VM_FEAT_CTRL 0
+#define KVM_LOONGARCH_VM_FEAT_X86BT 0
+#define KVM_LOONGARCH_VM_FEAT_ARMBT 1
+#define KVM_LOONGARCH_VM_FEAT_MIPSBT 2
+
/* Device Control API on vcpu fd */
#define KVM_LOONGARCH_VCPU_CPUCFG 0
#define KVM_LOONGARCH_VCPU_PVTIME_CTRL 1
diff --git a/arch/loongarch/kvm/vm.c b/arch/loongarch/kvm/vm.c
index 6b2e4f66ad26..09e05108c68b 100644
--- a/arch/loongarch/kvm/vm.c
+++ b/arch/loongarch/kvm/vm.c
@@ -99,7 +99,49 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
return r;
}
+static int kvm_vm_feature_has_attr(struct kvm *kvm, struct kvm_device_attr *attr)
+{
+ switch (attr->attr) {
+ case KVM_LOONGARCH_VM_FEAT_X86BT:
+ if (cpu_has_lbt_x86)
+ return 0;
+ return -ENXIO;
+ case KVM_LOONGARCH_VM_FEAT_ARMBT:
+ if (cpu_has_lbt_arm)
+ return 0;
+ return -ENXIO;
+ case KVM_LOONGARCH_VM_FEAT_MIPSBT:
+ if (cpu_has_lbt_mips)
+ return 0;
+ return -ENXIO;
+ default:
+ return -ENXIO;
+ }
+}
+
+static int kvm_vm_has_attr(struct kvm *kvm, struct kvm_device_attr *attr)
+{
+ switch (attr->group) {
+ case KVM_LOONGARCH_VM_FEAT_CTRL:
+ return kvm_vm_feature_has_attr(kvm, attr);
+ default:
+ return -ENXIO;
+ }
+}
+
int kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)
{
- return -ENOIOCTLCMD;
+ struct kvm *kvm = filp->private_data;
+ void __user *argp = (void __user *)arg;
+ struct kvm_device_attr attr;
+
+ switch (ioctl) {
+ case KVM_HAS_DEVICE_ATTR:
+ if (copy_from_user(&attr, argp, sizeof(attr)))
+ return -EFAULT;
+
+ return kvm_vm_has_attr(kvm, &attr);
+ default:
+ return -EINVAL;
+ }
}
--
2.39.3
