Re: [PATCH v3 0/4] powerpc/pseries/vas: VAS/NXGZIP support with LPM

[Haren Myneni <haren@linux.ibm.com>]

On Wed, 2022-02-23 at 19:38 +1000, Nicholas Piggin wrote:
> Excerpts from Haren Myneni's message of February 20, 2022 6:04 am:
> > Virtual Accelerator Switchboard (VAS) is an engine stays on the
> > chip. So all windows opened on a specific engine belongs to VAS
> > the chip.
> 
> The problem is more that PAPR does not virtualise the VAS windows,
> right? That's a whole other gripe but nothing you can do about it
> here.

Yes, There is no virtualization with VAS windows and they are specific
to the chip. 

> 
> Thanks,
> Nick
> 
> > The hypervisor expects the partition to close all
> > active windows on the sources system and reopen them after
> > migration on the destination machine.
> > 
> > This patch series adds VAS support with the partition migration.
> > When the migration initiates, the VAS migration handler will be
> > invoked before pseries_suspend() to close all active windows and
> > mark them in-active with VAS_WIN_MIGRATE_CLOSE status. Whereas
> > this migration handler is called after migration to reopen all
> > windows which has VAS_WIN_MIGRATE_CLOSE status and make them
> > active again. The user space gets paste instruction failure
> > when it sends requests on these in-active windows.
> > 
> > These patches depend on VAS/DLPAR support patch series
> > 
> > Changes in v2:
> > - Added new patch "Define global hv_cop_caps struct" to eliminate
> >   memory allocation failure during migration (suggestion by
> >   Nathan Lynch)
> > 
> > Changes in v3:
> > - Rebase on 5.17-rc4
> > - Naming changes for VAS capability struct elemets based on the V4
> > DLPAR
> >   support patch series.
> > 
> > Haren Myneni (4):
> >   powerpc/pseries/vas: Define global hv_cop_caps struct
> >   powerpc/pseries/vas: Modify reconfig open/close functions for
> >     migration
> >   powerpc/pseries/vas: Add VAS migration handler
> >   powerpc/pseries/vas: Disable window open during migration
> > 
> >  arch/powerpc/include/asm/vas.h            |   2 +
> >  arch/powerpc/platforms/pseries/mobility.c |   5 +
> >  arch/powerpc/platforms/pseries/vas.c      | 234 +++++++++++++++++-
> > ----
> >  arch/powerpc/platforms/pseries/vas.h      |   6 +
> >  4 files changed, 201 insertions(+), 46 deletions(-)
> > 
> > -- 
> > 2.27.0
> > 
> > 
> >