[PATCH 3/9] KVM: s390: pv: Add query interface

Janosch Frank
2022-02-23T09:20:36Z

Some of the query information is already available via sysfs but
having a IOCTL makes the information easier to retrieve.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
---
arch/s390/kvm/kvm-s390.c | 47 ++++++++++++++++++++++++++++++++++++++++
include/uapi/linux/kvm.h | 23 ++++++++++++++++++++
2 files changed, 70 insertions(+)

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index faa85397b6fb..837f898ad2ff 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -2217,6 +2217,34 @@ static int kvm_s390_cpus_to_pv(struct kvm *kvm, u16 *rc, u16 *rrc)
return r;
}

+static int kvm_s390_handle_pv_info(struct kvm_s390_pv_info *info)
+{
+ u32 len;
+
+ switch (info->header.id) {
+ case KVM_PV_INFO_VM: {
+ len = sizeof(info->header) + sizeof(info->vm);
+
+ if (info->header.len < len)
+ return -EINVAL;
+
+ memcpy(info->vm.inst_calls_list,
+ uv_info.inst_calls_list,
+ sizeof(uv_info.inst_calls_list));
+
+ /* It's max cpuidm not max cpus so it's off by one */
+ info->vm.max_cpus = uv_info.max_guest_cpu_id + 1;
+ info->vm.max_guests = uv_info.max_num_sec_conf;
+ info->vm.max_guest_addr = uv_info.max_sec_stor_addr;
+ info->vm.feature_indication = uv_info.uv_feature_indications;
+
+ return 0;
+ }
+ default:
+ return -EINVAL;
+ }
+}
+
static int kvm_s390_handle_pv(struct kvm *kvm, struct kvm_pv_cmd *cmd)
{
int r = 0;
@@ -2353,6 +2381,25 @@ static int kvm_s390_handle_pv(struct kvm *kvm, struct kvm_pv_cmd *cmd)
cmd->rc, cmd->rrc);
break;
}
+ case KVM_PV_INFO: {
+ struct kvm_s390_pv_info info = {};
+
+ if (copy_from_user(&info, argp, sizeof(info.header)))
+ return -EFAULT;
+
+ if (info.header.len < sizeof(info.header))
+ return -EINVAL;
+
+ r = kvm_s390_handle_pv_info(&info);
+ if (r)
+ return r;
+
+ r = copy_to_user(argp, &info, sizeof(info));
+
+ if (r)
+ return -EFAULT;
+ return 0;
+ }
default:
r = -ENOTTY;
}
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index dbc550bbd9fa..96fceb204a92 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1642,6 +1642,28 @@ struct kvm_s390_pv_unp {
__u64 tweak;
};

+enum pv_cmd_info_id {
+ KVM_PV_INFO_VM,
+};
+
+struct kvm_s390_pv_info_vm {
+ __u64 inst_calls_list[4];
+ __u64 max_cpus;
+ __u64 max_guests;
+ __u64 max_guest_addr;
+ __u64 feature_indication;
+};
+
+struct kvm_s390_pv_info_header {
+ __u32 id;
+ __u32 len;
+};
+
+struct kvm_s390_pv_info {
+ struct kvm_s390_pv_info_header header;
+ struct kvm_s390_pv_info_vm vm;
+};
+
enum pv_cmd_id {
KVM_PV_ENABLE,
KVM_PV_DISABLE,
@@ -1650,6 +1672,7 @@ enum pv_cmd_id {
KVM_PV_VERIFY,
KVM_PV_PREP_RESET,
KVM_PV_UNSHARE_ALL,
+ KVM_PV_INFO,
};

struct kvm_pv_cmd {
--
2.32.0