qemu-devel
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [PATCH v4 16/21] i386: track explicit 'hv-*' features enablement/dis


From: Vitaly Kuznetsov
Subject: Re: [PATCH v4 16/21] i386: track explicit 'hv-*' features enablement/disablement
Date: Mon, 15 Feb 2021 09:56:19 +0100

Igor Mammedov <imammedo@redhat.com> writes:

> On Fri, 12 Feb 2021 16:26:03 +0100
> Vitaly Kuznetsov <vkuznets@redhat.com> wrote:
>
>> Vitaly Kuznetsov <vkuznets@redhat.com> writes:
>> 
>> > Igor Mammedov <imammedo@redhat.com> writes:
>> >  
>> >>
>> >> Please try reusing scratch CPU approach, see
>> >>   kvm_arm_get_host_cpu_features()
>> >> for an example. You will very likely end up with simpler series,
>> >> compared to reinventing wheel.  
>> >
>> > Even if I do that (and I serioulsy doubt it's going to be easier than
>> > just adding two 'u64's, kvm_arm_get_host_cpu_features() alone is 200
>> > lines long) this is not going to give us what we need to distinguish
>> > between
>> >
>> > 'hv-passthrough,hv-evmcs'
>> >
>> > and 
>> >
>> > 'hv-passthrough'
>> >
>> > when 'hv-evmcs' *is* supported by the host. When guest CPU lacks VMX we
>> > don't want to enable it unless it was requested explicitly (former but
>> > not the later).  
>> 
>> ... and if for whatever reason we decide that this is also bad/not
>> needed, I can just drop patches 16-18 from the series (leaving
>> 'hv-passthrough,hv-feature=off' problem to better times).
> that's also an option,
> we would need to make sure that hv-passthrough is mutually exclusive
> with ''all'' other hv- properties to avoid above combination being
> ever (mis)used.

That's an option to finally get these patches merged, not a good option
for end users. 

'hv-passthrough,hv-feature' works today and it's useful. Should we drop
it?

'hv-passthrough/hv-default' and 'hv-passthrough/hv-default,hv-evmcs'
should give us sane results.

'hv-passthrough,hv-feature=off' is convenient.

Why droppping this all? To save 9 (nine) lines of code in the parser? 

-- 
Vitaly




reply via email to

[Prev in Thread] Current Thread [Next in Thread]