Number of CPUs is not validated

[jandubois]

Setting to 0 is valid because it is the "null" value, meaning to use the default setting.

I wonder if the --cpus flag should not print a message in that case.

Setting to negative numbers is not caught by validation, but will cause a failure to start the VM. This must be caught; limactl edit should never leave lima.yaml in a non-startable state.

We do have validation to reject string values, even though allowing max or host would maybe make sense (host being the number of CPUs of the host, and max maybe 2 less?).

❯ l edit -y foo --cpus 1
INFO[0000] Instance "foo" configuration edited

❯ l edit -y foo --cpus 0
INFO[0000] Instance "foo" configuration edited

❯ l edit -y foo --cpus -1
INFO[0000] Instance "foo" configuration edited

❯ l edit -y foo --cpus max
FATA[0000] invalid argument "max" for "--cpus" flag: strconv.ParseInt: parsing "max": invalid syntax

[afbjorklund]

Setting to 0 is valid because it is the "null" value, meaning to use the default setting.

Is this documented anywhere? I thought null (~) was the null value, in the lima.yaml.

---

I think it should be an integer, but we do allow string for --memory now - so maybe that is just backwards thinking...

Having to quote seems like a breaking change, so it would probably have to accept both cpus: 4 and cpus: host

                "cpus": {
                    "oneOf": [
                        {
                            "type": "integer"
                        },
                        {
                            "type": "string"
                        },
                        {
                            "type": "null"
                        }
                    ]
                },

EDIT: We don't actually have to change the JSON schema, only the limayaml type (from int to string)

However, it is not possible to validate the integer without invoking the driver - so not sure we should?

[k-veda]

Hello, @sneugle and I are students at UT-Austin taking a course on virtualization. As part of it, we are tasked to work on an open source project. We previously spoke to a maintainer for this repository on the Slack, and were wondering if we could be assigned this issue?

[afbjorklund]

Hello, @sneugle and I are students at UT-Austin taking a course on virtualization. As part of it, we are tasked to work on an open source project. We previously spoke to a maintainer for this repository on the Slack, and were wondering if we could be assigned this issue?

This issue is more about yaml engineering than it is about virtualization, but contributions are welcome

[afbjorklund]

Setting to negative numbers is not caught by validation, but will cause a failure to start the VM.

This depends on the driver, though. Some driver could (theoretically) have them as magic numbers?