Re: [Qemu-devel] [PATCH v2] qemu-kvm/pci-assign: 64 bits bar emulation

[Hao, Xudong]

> -----Original Message-----
> From: Alex Williamson [mailto:address@hidden
> Sent: Thursday, December 20, 2012 12:06 AM
> To: Hao, Xudong
> Cc: address@hidden; address@hidden; address@hidden;
> address@hidden
> Subject: Re: [PATCH v2] qemu-kvm/pci-assign: 64 bits bar emulation
> 
> On Wed, 2012-12-19 at 16:47 +0800, Xudong Hao wrote:
> > Enable 64 bits bar emulation.
> >
> > v2 changes from v1:
> > - Change 0lx% to 0x%016 when print a 64 bit variable.
> >
> > Test pass with the current seabios which already support 64bit pci bars.
> >
> > Signed-off-by: Xudong Hao <address@hidden>
> > ---
> >  hw/kvm/pci-assign.c |   22 ++++++++++++++--------
> >  1 files changed, 14 insertions(+), 8 deletions(-)
> >
> > diff --git a/hw/kvm/pci-assign.c b/hw/kvm/pci-assign.c
> > index 7a0998c..fb58ca9 100644
> > --- a/hw/kvm/pci-assign.c
> > +++ b/hw/kvm/pci-assign.c
> > @@ -46,6 +46,7 @@
> >  #define IORESOURCE_IRQ      0x00000400
> >  #define IORESOURCE_DMA      0x00000800
> >  #define IORESOURCE_PREFETCH 0x00002000  /* No side effects */
> > +#define IORESOURCE_MEM_64   0x00100000
> >
> >  //#define DEVICE_ASSIGNMENT_DEBUG
> >
> > @@ -442,9 +443,13 @@ static int assigned_dev_register_regions(PCIRegion
> *io_regions,
> >
> >          /* handle memory io regions */
> >          if (cur_region->type & IORESOURCE_MEM) {
> > -            int t = cur_region->type & IORESOURCE_PREFETCH
> > -                ? PCI_BASE_ADDRESS_MEM_PREFETCH
> > -                : PCI_BASE_ADDRESS_SPACE_MEMORY;
> > +            int t = PCI_BASE_ADDRESS_SPACE_MEMORY;
> > +            if (cur_region->type & IORESOURCE_PREFETCH) {
> > +                t |= PCI_BASE_ADDRESS_MEM_PREFETCH;
> > +            }
> > +            if (cur_region->type & IORESOURCE_MEM_64) {
> > +                t |= PCI_BASE_ADDRESS_MEM_TYPE_64;
> > +            }
> >
> >              /* map physical memory */
> >              pci_dev->v_addrs[i].u.r_virtbase = mmap(NULL,
> cur_region->size,
> > @@ -468,10 +473,10 @@ static int
> assigned_dev_register_regions(PCIRegion *io_regions,
> >                  (cur_region->base_addr & 0xFFF);
> >
> >              if (cur_region->size & 0xFFF) {
> > -                error_report("PCI region %d at address 0x%" PRIx64 "
> has "
> > -                             "size 0x%" PRIx64 ", which is not a
> multiple of "
> > -                             "4K.  You might experience some
> performance hit "
> > -                             "due to that.",
> > +                error_report("PCI region %d at address 0x%016" PRIx64
> " has "
> > +                             "size 0x%016" PRIx64 ", which is not a
> multiple "
> > +                             "of 4K.  You might experience some
> performance "
> > +                             "hit due to that.",
> 
> nit, these changes to %016 don't make sense.  If the size is not a
> multiple of 4k, then it's less than 4k, so adding leading zeros is just
> a waste.  Also, are BARs that small likely to be 64bit?  Seems like not,
> so more unnecessary zeros.  Thanks,
> 

Alex,
You're right for this error_report print less than 4k. So your comments is 
removing 016 and just remain the original code is fine, right?