Re: [PATCH 2/4] s390/pci: track whether util_str is valid in the zpci_dev

[Matthew Rosato]

On 9/21/20 5:41 AM, Niklas Schnelle wrote:
> Hi Matthew,
>
> On 9/19/20 5:28 PM, Matthew Rosato wrote:
> > We'll need to keep track of whether or not the byte string in util_str is
> > valid and thus needs to be passed to a vfio-pci passthrough device.
> >
> > Signed-off-by: Matthew Rosato <mjrosato@xxxxxxxxxxxxx>
> > ---
> >   arch/s390/include/asm/pci.h | 3 ++-
> >   arch/s390/pci/pci_clp.c     | 1 +
> >   2 files changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/arch/s390/include/asm/pci.h b/arch/s390/include/asm/pci.h
> > index 882e233..32eb975 100644
> > --- a/arch/s390/include/asm/pci.h
> > +++ b/arch/s390/include/asm/pci.h
> > @@ -132,7 +132,8 @@ struct zpci_dev {
> >   	u8		rid_available	: 1;
> >   	u8		has_hp_slot	: 1;
> >   	u8		is_physfn	: 1;
> > -	u8		reserved	: 5;
> > +	u8		util_avail	: 1;
>
> Any reason you're not matching the util_str_avail name in the response struct? > I think this is currently always an EBCDIC encoded string so the 
information that
> even if it looks like binary for anyone with a non-mainframe background
> it is in fact a string seems quite helpful.

Frankly, the dropping of 'str_' was arbitrary on my part -- I'll go 
ahead and rename it to util_str_avail with v2.

> Other than that
>
> Acked-by: Niklas Schnelle <schnelle@xxxxxxxxxxxxx>

Thanks!

> > +	u8		reserved	: 4;
> >   	unsigned int	devfn;		/* DEVFN part of the RID*/
> >   
> >   	struct mutex lock;
> > diff --git a/arch/s390/pci/pci_clp.c b/arch/s390/pci/pci_clp.c
> > index 48bf316..d011134 100644
> > --- a/arch/s390/pci/pci_clp.c
> > +++ b/arch/s390/pci/pci_clp.c
> > @@ -168,6 +168,7 @@ static int clp_store_query_pci_fn(struct zpci_dev *zdev,
> >   	if (response->util_str_avail) {
> >   		memcpy(zdev->util_str, response->util_str,
> >   		       sizeof(zdev->util_str));
> > +		zdev->util_avail = 1;
> >   	}
> >   	zdev->mio_capable = response->mio_addr_avail;
> >   	for (i = 0; i < PCI_STD_NUM_BARS; i++) {