Re: [Qemu-devel] [PATCH 2/2] ppc-e500: implement PCI INTx routing

["Michael S. Tsirkin" <mst@redhat.com>]

On Thu, Dec 19, 2013 at 03:39:58PM +0000, Bharat.Bhushan@freescale.com wrote:
> 
> 
> > -----Original Message-----
> > From: Michael S. Tsirkin [mailto:mst@redhat.com]
> > Sent: Thursday, December 19, 2013 3:55 AM
> > To: Alexander Graf
> > Cc: Bhushan Bharat-R65777; Wood Scott-B07421; QEMU Developers; qemu-ppc; Bhushan
> > Bharat-R65777
> > Subject: Re: [PATCH 2/2] ppc-e500: implement PCI INTx routing
> > 
> > On Wed, Dec 18, 2013 at 10:53:32PM +0100, Alexander Graf wrote:
> > >
> > > On 28.11.2013, at 07:35, Bharat Bhushan <r65777@freescale.com> wrote:
> > >
> > > > This patch adds pci pin to irq_num routing callback Without this
> > > > patch we gets below warning
> > > >
> > > > "
> > > >  PCI: Bug - unimplemented PCI INTx routing (e500-pcihost)
> > > >  qemu-system-ppc64: PCI: Bug - unimplemented PCI INTx routing
> > > > (e500-pcihost) "
> > > >
> > > > Signed-off-by: Bharat Bhushan <Bharat.Bhushan@freescale.com>
> > > > ---
> > > > hw/pci-host/ppce500.c |   20 ++++++++++++++++++--
> > > > 1 files changed, 18 insertions(+), 2 deletions(-)
> > > >
> > > > diff --git a/hw/pci-host/ppce500.c b/hw/pci-host/ppce500.c index
> > > > 49bfcc6..3c4cf9e 100644
> > > > --- a/hw/pci-host/ppce500.c
> > > > +++ b/hw/pci-host/ppce500.c
> > > > @@ -88,6 +88,7 @@ struct PPCE500PCIState {
> > > >     struct pci_inbound pib[PPCE500_PCI_NR_PIBS];
> > > >     uint32_t gasket_time;
> > > >     qemu_irq irq[PCI_NUM_PINS];
> > > > +    uint32_t irq_num[PCI_NUM_PINS];
> > > >     uint32_t first_slot;
> > > >     /* mmio maps */
> > > >     MemoryRegion container;
> > > > @@ -267,13 +268,26 @@ static int mpc85xx_pci_map_irq(PCIDevice
> > > > *pci_dev, int pin)
> > > >
> > > > static void mpc85xx_pci_set_irq(void *opaque, int pin, int level) {
> > > > -    qemu_irq *pic = opaque;
> > > > +    PPCE500PCIState *s = opaque;
> > > > +    qemu_irq *pic = s->irq;;
> > >
> > > Double semicolon?
> 
> Ok, will correct.
> 
> > >
> > > >
> > > >     pci_debug("%s: PCI irq %d, level:%d\n", __func__, pin , level);
> > > >
> > > >     qemu_set_irq(pic[pin], level);
> > > > }
> > > >
> > > > +static PCIINTxRoute e500_route_intx_pin_to_irq(void *opaque, int
> > > > +pin) {
> > > > +    PCIINTxRoute route;
> > > > +    PPCE500PCIState *s = opaque;
> > > > +
> > > > +    route.mode = PCI_INTX_ENABLED;
> > > > +    route.irq = s->irq_num[pin];
> > > > +
> > > > +    pci_debug("%s: PCI irq-pin = %d, irq_num= %d\n", __func__, pin,
> > route.irq);
> > > > +    return route;
> > > > +}
> > > > +
> > > > static const VMStateDescription vmstate_pci_outbound = {
> > > >     .name = "pci_outbound",
> > > >     .version_id = 0,
> > > > @@ -350,12 +364,13 @@ static int e500_pcihost_initfn(SysBusDevice
> > > > *dev)
> > > >
> > > >     for (i = 0; i < ARRAY_SIZE(s->irq); i++) {
> > > >         sysbus_init_irq(dev, &s->irq[i]);
> > > > +        s->irq_num[i] = i + 1;
> > >
> > > Doesn't this duplicate the logic from ppce500_pci_map_irq_slot()? I don't
> > understand the purpose of this whole exercise to be honest.
> > >
> > > Michael, could you please shed some light on this?
> > >
> > >
> > > Alex
> > 
> > This is printed by pci_device_route_intx_to_irq - it's used by device assignment
> > and vfio to figure out which irq does a given pci device drive.
> 
> Yes, exactly same reason.
> 
> Thanks
> -Bharat


you probably should say in commit log 
"this makes vfio work on ppc" - assumng it works for you of course.
as it is it makes it look like you are just trying to shut off
a warning.

> > 
> > > >     }
> > > >
> > > >     memory_region_init(&s->pio, OBJECT(s), "pci-pio",
> > > > PCIE500_PCI_IOLEN);
> > > >
> > > >     b = pci_register_bus(DEVICE(dev), NULL, mpc85xx_pci_set_irq,
> > > > -                         mpc85xx_pci_map_irq, s->irq, address_space_mem,
> > > > +                         mpc85xx_pci_map_irq, s, address_space_mem,
> > > >                          &s->pio, PCI_DEVFN(s->first_slot, 0), 4,
> > TYPE_PCI_BUS);
> > > >     h->bus = b;
> > > >
> > > > @@ -373,6 +388,7 @@ static int e500_pcihost_initfn(SysBusDevice *dev)
> > > >     memory_region_add_subregion(&s->container, PCIE500_REG_BASE, &s->iomem);
> > > >     sysbus_init_mmio(dev, &s->container);
> > > >     sysbus_init_mmio(dev, &s->pio);
> > > > +    pci_bus_set_route_irq_fn(b, e500_route_intx_pin_to_irq);
> > > >
> > > >     return 0;
> > > > }
> > > > --
> > > > 1.7.0.4
> > > >
> > > >
> >