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 10:39 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 Thu, 2012-12-20 at 01:52 +0000, Hao, Xudong wrote:
> > > -----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?
> 
> Yes, I'd just drop that chunk and leave the original error string.

I'll send next version to remove it.

> Thanks,
> 
> Alex