Re: [kvm-unit-tests PATCH 2/7] pci: use uint32_t for unsigned long values

Andrew Jones
2020-02-28T12:47:06Z

On Fri, Feb 28, 2020 at 12:04:38PM +0100, Paolo Bonzini wrote:
> On 26/02/20 10:44, Bill Wendling wrote:
> > The "pci_bar_*" functions use 64-bit masks, but the results are assigned
> > to 32-bit variables. Use 32-bit masks, since we're interested only in
> > the least significant 4-bits.
> >
> > Signed-off-by: Bill Wendling <morbo@google.com>
> > ---
> > lib/linux/pci_regs.h | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/lib/linux/pci_regs.h b/lib/linux/pci_regs.h
> > index 1becea8..3bc2b92 100644
> > --- a/lib/linux/pci_regs.h
> > +++ b/lib/linux/pci_regs.h
> > @@ -96,8 +96,8 @@
> > #define PCI_BASE_ADDRESS_MEM_TYPE_1M 0x02 /* Below 1M [obsolete] */
> > #define PCI_BASE_ADDRESS_MEM_TYPE_64 0x04 /* 64 bit address */
> > #define PCI_BASE_ADDRESS_MEM_PREFETCH 0x08 /* prefetchable? */
> > -#define PCI_BASE_ADDRESS_MEM_MASK (~0x0fUL)
> > -#define PCI_BASE_ADDRESS_IO_MASK (~0x03UL)
> > +#define PCI_BASE_ADDRESS_MEM_MASK (~0x0fU)
> > +#define PCI_BASE_ADDRESS_IO_MASK (~0x03U)
> > /* bit 1 is reserved if address_space = 1 */
> >
> > /* Header type 0 (normal devices) */
> >
>
> Removing the "U" is even better because it will then sign-extend
> automatically.
>

We don't want this patch at all though. We shouldn't change pci_regs.h
since it comes from linux and someday we may update again and lose
any changes we make. We should change how these masks are used instead.

Thanks,
drew