lkml.org 
[lkml]   [2022]   [Sep]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] kvm/x86: reserve bit KVM_HINTS_PHYS_ADDRESS_SIZE_DATA_VALID
On Fri, Sep 09, 2022 at 07:02:24AM +0200, Gerd Hoffmann wrote:
> On Thu, Sep 08, 2022 at 02:52:36PM +0000, Sean Christopherson wrote:
> > On Thu, Sep 08, 2022, Gerd Hoffmann wrote:
> > > -#define KVM_HINTS_REALTIME 0
> > > +#define KVM_HINTS_REALTIME 0
> > > +#define KVM_HINTS_PHYS_ADDRESS_SIZE_DATA_VALID 1
> >
> > Why does KVM need to get involved? This is purely a userspace problem.
>
> It doesn't. I only need reserve a hints bit, and the canonical source
> for that happens to live in the kernel. That's why this patch doesn't
> touch any actual code ;)
>
> > E.g. why not use QEMU's fw_cfg to communicate this information to the
> > guest?
>
> That is indeed the other obvious way to implement this. Given this
> information will be needed in code paths which already do CPUID queries
> using CPUID to transport that information looked like the better option
> to me.

I'd like to move forward with this.

So, any comment further comments and opinions?
Is it ok to grab a hints bit given the explanation above?
Or should I go for the fw_cfg approach?

thanks & take care,
Gerd

\
 
 \ /
  Last update: 2022-09-21 15:43    [W:0.140 / U:0.280 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site