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Date:   Wed, 2 Nov 2022 11:45:12 -0700
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Subject: Re: [PATCH v6 13/21] gunyah: vm_mgr: Introduce basic VM Manager
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To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>, <mec@shout.net>
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References: <20221026185846.3983888-1-quic_eberman@quicinc.com>
 <20221026185846.3983888-14-quic_eberman@quicinc.com>
 <Y2H8oh7AvYDiMqKs@kroah.com>
From:   Elliot Berman <quic_eberman@quicinc.com>
In-Reply-To: <Y2H8oh7AvYDiMqKs@kroah.com>
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+Michael

On 11/1/2022 10:14 PM, Greg Kroah-Hartman wrote:
> On Wed, Oct 26, 2022 at 11:58:38AM -0700, Elliot Berman wrote:
>> +#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?

> 
> 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.

Thanks,
Elliot