On Mon, Dec 13, 2010 at 04:56:29PM -0700, Alex Williamson wrote:
> On Tue, 2010-12-14 at 00:25 +0100, Jan Kiszka wrote:
> > From: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
> >
> > Define a mask of PCI command register bits that need to be emulated,
> > i.e. read back from their shadow state. We will need this for
> > selectively emulating the INTx mask bit.
> >
> > Note: No initialization of emulate_cmd_mask to zero needed, the device
> > state is already zero-initialized.
> >
> > Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
> > ---
> > hw/device-assignment.c | 18 ++++++++++--------
> > hw/device-assignment.h | 2 +-
> > 2 files changed, 11 insertions(+), 9 deletions(-)
> >
> > diff --git a/hw/device-assignment.c b/hw/device-assignment.c
> > index ef045f4..26d3bd7 100644
> > --- a/hw/device-assignment.c
> > +++ b/hw/device-assignment.c
> > @@ -525,14 +525,17 @@ again:
> > DEBUG("(%x.%x): address=%04x val=0x%08x len=%d\n",
> > (d->devfn >> 3) & 0x1F, (d->devfn & 0x7), address, val, len);
> >
> > - if (pci_dev->need_emulate_cmd &&
> > + if (pci_dev->emulate_cmd_mask &&
> > ranges_overlap(address, len, PCI_COMMAND, 2)) {
> > if (address == PCI_COMMAND) {
> > - val &= 0xffff0000;
> > - val |= pci_default_read_config(d, PCI_COMMAND, 2);
> > + val &= ~pci_dev->emulate_cmd_mask;
> > + val |= pci_default_read_config(d, PCI_COMMAND, 2) &
> > + pci_dev->emulate_cmd_mask;
> > } else {
> > /* high-byte access */
> > - val = pci_default_read_config(d, PCI_COMMAND+1, 1);
> > + val &= ~(pci_dev->emulate_cmd_mask >> 8);
> > + val |= pci_default_read_config(d, PCI_COMMAND+1, 1) &
> > + (pci_dev->emulate_cmd_mask >> 8);
> > }
> > }
>
> We should definitely be using merge_bits here, this is the sort of thing
> I had in mind for it:
>
> val = merge_bits(val, pci_default_read_config(d, address, len), PCI_COMMAND, pci_dev->emulate_cmd_mask);
Not a comment on this patch at all, rather on
assigned-devices support code generally:
I think code will become cleaner if we add a mask array mapping the
config space, along the lines of wmask and friends in pci.c
I think this will make it possible to mostly get rid of
merge_bits and tricky range check hacks.
> > @@ -800,10 +803,9 @@ again:
> >
> > /* dealing with virtual function device */
> > snprintf(name, sizeof(name), "%sphysfn/", dir);
> > - if (!stat(name, &statbuf))
> > - pci_dev->need_emulate_cmd = 1;
> > - else
> > - pci_dev->need_emulate_cmd = 0;
> > + if (!stat(name, &statbuf)) {
> > + pci_dev->emulate_cmd_mask = 0xffff;
> > + }
> >
> > dev->region_number = r;
> > return 0;
> > diff --git a/hw/device-assignment.h b/hw/device-assignment.h
> > index c94a730..9ead022 100644
> > --- a/hw/device-assignment.h
> > +++ b/hw/device-assignment.h
> > @@ -109,7 +109,7 @@ typedef struct AssignedDevice {
> > void *msix_table_page;
> > target_phys_addr_t msix_table_addr;
> > int mmio_index;
> > - int need_emulate_cmd;
> > + uint32_t emulate_cmd_mask;
> > char *configfd_name;
> > QLIST_ENTRY(AssignedDevice) next;
> > } AssignedDevice;
>
>
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