Re: [Qemu-devel] RFC: vfio API changes needed for powerpc (v3)

[Yoder Stuart-B08248]

> -----Original Message-----
> From: Wood Scott-B07421
> Sent: Friday, April 05, 2013 5:17 PM
> To: Yoder Stuart-B08248
> Cc: Alex Williamson; Wood Scott-B07421; address@hidden; Bhushan 
> Bharat-R65777; Sethi Varun-B16395;
> address@hidden; address@hidden; address@hidden
> Subject: Re: RFC: vfio API changes needed for powerpc (v3)
> 
> On 04/04/2013 05:10:27 PM, Yoder Stuart-B08248 wrote:
> > /*
> >  * VFIO_IOMMU_PAMU_UNMAP_MSI_BANK
> >  *
> >  * Unmaps the MSI bank at the specified iova.
> >  * Caller provides struct vfio_pamu_msi_bank_unmap with all fields
> > set.
> >  * Operates on VFIO file descriptor (/dev/vfio/vfio).
> >  * Return: 0 on success, -errno on failure
> >  */
> >
> > struct vfio_pamu_msi_bank_unmap {
> >         __u32   argsz;
> >         __u32   flags;     /* no flags currently */
> >         __u64   iova;      /* the iova to be unmapped to */
> > };
> > #define VFIO_IOMMU_PAMU_UNMAP_MSI_BANK  _IO(VFIO_TYPE, VFIO_BASE + x,
> >         struct vfio_pamu_msi_bank_unmap )
> 
> What happens if a normal unmap call is done on the MSI iova?  Do we
> need a separate unmap?

I was thinking a normal unmap on an MSI windows would be an error...but
I'm not set on that.   I put the msi unmap there to make things symmetric,
a normal unmap would work as well...and then we could drop the msi unmap.

Stuart