Re: [PATCH v5 26/26] nvme: make lba data size configurable

[Maxim Levitsky]

On Thu, 2020-02-06 at 08:24 +0100, Klaus Birkelund Jensen wrote:
> On Feb  5 01:43, Keith Busch wrote:
> > On Tue, Feb 04, 2020 at 10:52:08AM +0100, Klaus Jensen wrote:
> > > Signed-off-by: Klaus Jensen <address@hidden>
> > > ---
> > >  hw/block/nvme-ns.c | 2 +-
> > >  hw/block/nvme-ns.h | 4 +++-
> > >  hw/block/nvme.c    | 1 +
> > >  3 files changed, 5 insertions(+), 2 deletions(-)
> > > 
> > > diff --git a/hw/block/nvme-ns.c b/hw/block/nvme-ns.c
> > > index 0e5be44486f4..981d7101b8f2 100644
> > > --- a/hw/block/nvme-ns.c
> > > +++ b/hw/block/nvme-ns.c
> > > @@ -18,7 +18,7 @@ static int nvme_ns_init(NvmeNamespace *ns)
> > >  {
> > >      NvmeIdNs *id_ns = &ns->id_ns;
> > >  
> > > -    id_ns->lbaf[0].ds = BDRV_SECTOR_BITS;
> > > +    id_ns->lbaf[0].ds = ns->params.lbads;
> > >      id_ns->nuse = id_ns->ncap = id_ns->nsze =
> > >          cpu_to_le64(nvme_ns_nlbas(ns));
> > >  
> > > diff --git a/hw/block/nvme-ns.h b/hw/block/nvme-ns.h
> > > index b564bac25f6d..f1fe4db78b41 100644
> > > --- a/hw/block/nvme-ns.h
> > > +++ b/hw/block/nvme-ns.h
> > > @@ -7,10 +7,12 @@
> > >  
> > >  #define DEFINE_NVME_NS_PROPERTIES(_state, _props) \
> > >      DEFINE_PROP_DRIVE("drive", _state, blk), \
> > > -    DEFINE_PROP_UINT32("nsid", _state, _props.nsid, 0)
> > > +    DEFINE_PROP_UINT32("nsid", _state, _props.nsid, 0), \
> > > +    DEFINE_PROP_UINT8("lbads", _state, _props.lbads, BDRV_SECTOR_BITS)
> > 
> > I think we need to validate the parameter is between 9 and 12 before
> > trusting it can be used safely.
> > 
> > Alternatively, add supported formats to the lbaf array and let the host
> > decide on a live system with the 'format' command.
> 
> The device does not yet support Format NVM, but we have a patch ready
> for that to be submitted with a new series when this is merged.
> 
> For now, while it does not support Format, I will change this patch such
> that it defaults to 9 (BRDV_SECTOR_BITS) and only accept 12 as an
> alternative (while always keeping the number of formats available to 1).
Looks like a good idea.

Best regards,
        Maxim Levitsky