On Wed, Nov 02, 2022 at 11:45:12AM -0700, Elliot Berman wrote:

+Michael

On 11/1/2022 10:14 PM, Greg Kroah-Hartman wrote:

quoted

On Wed, Oct 26, 2022 at 11:58:38AM -0700, Elliot Berman wrote:

quoted

+#define GH_CREATE_VM			_IO(GH_IOCTL_TYPE, 0x40) /* Returns a Gunyah VM fd */

Why 0x40?  Why not just use the same KVM ioctl numbers and names as you
are doing the same thing as them, right?

We've designed so that there are a few ioctls that will feel similar to KVM
ioctls since we know this design has been successful, but we don't intend to
support KVM ioctls 1:1. Gunyah has different semantics for many of the
name-identical ioctls. It seems odd to mix some re-used KVM ioctls with
novel Gunyah ioctls?

Even if you don't support it 1:1, at least for the ones that are the
same thing, pick the same numbers as that's a nicer thing to do, right?

quoted

Normally your first ioctl is "0x01", not "0x40", so this feels really
odd.

Documentation/userspace-api/ioctl/iocl-number.rst advises to pick an unused
block. We picked ioctl code 'G' and unused sequence numbers under that code.
I'm ok to move the block around.

How do you know you picked an unused block?  It wasn't obvious where you
got these values from at all, and unfortunatly, no one really ever
updates that documentation file.  Luckily it never really matters.

thanks,

greg k-h

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