Re: [PATCH v2 07/18] hw/ide/piix: Ensure IDE output IRQs are wired at realization

+Daniel, Igor, Marcel & libvirt On 16/2/23 16:33, Philippe Mathieu-Daudé wrote: > On 16/2/23 15:43, Bernhard Beschow wrote: > > > > > > On Wed, Feb 15, 2023 at 5:20 PM Philippe Mathieu-Daudé > > <philmd(a)linaro.org <mailto:philmd@linaro.org>> wrote: > > > >     Ensure both IDE output IRQ lines are wired. > > > >     We can remove the last use of isa_get_irq(NULL). > > > >     Signed-off-by: Philippe Mathieu-Daudé <philmd(a)linaro.org > >     <mailto:philmd@linaro.org>> > >     --- > >       hw/ide/piix.c | 13 ++++++++----- > >       1 file changed, 8 insertions(+), 5 deletions(-) > > > >     diff --git a/hw/ide/piix.c b/hw/ide/piix.c > >     index 9d876dd4a7..b75a4ddcca 100644 > >     --- a/hw/ide/piix.c > >     +++ b/hw/ide/piix.c > >     @@ -133,14 +133,17 @@ static bool pci_piix_init_bus(PCIIDEState *d, > >     unsigned i, Error **errp) > >           static const struct { > >               int iobase; > >               int iobase2; > >     -        int isairq; > >           } port_info[] = { > >     -        {0x1f0, 0x3f6, 14}, > >     -        {0x170, 0x376, 15}, > >     +        {0x1f0, 0x3f6}, > >     +        {0x170, 0x376}, > >           }; > >           int ret; > > > >     -    qemu_irq irq_out = d->irq[i] ? : isa_get_irq(NULL, > >     port_info[i].isairq); > >     +    if (!d->irq[i]) { > >     +        error_setg(errp, "output IDE IRQ %u not connected", i); > >     +        return false; > >     +    } > >     + > >           ide_bus_init(&d->bus[i], sizeof(d->bus[i]), DEVICE(d), i, 2); > >           ret = ide_init_ioport(&d->bus[i], NULL, port_info[i].iobase, > >                                 port_info[i].iobase2); > >     @@ -149,7 +152,7 @@ static bool pci_piix_init_bus(PCIIDEState *d, > >     unsigned i, Error **errp) > >                                object_get_typename(OBJECT(d)), i); > >               return false; > >           } > >     -    ide_bus_init_output_irq(&d->bus[i], irq_out); > >     +    ide_bus_init_output_irq(&d->bus[i], d->irq[i]); > > > >           bmdma_init(&d->bus[i], &d->bmdma[i], d); > >           d->bmdma[i].bus = &d->bus[i]; > >     --     2.38.1 > > > > > > This now breaks user-created  piix3-ide: > > > >    qemu-system-x86_64 -M q35 -device piix3-ide > > > > Results in: > > > >    qemu-system-x86_64: -device piix3-ide: output IDE IRQ 0 not connected > > Thank you for this real-life-impossible-but-exists-in-QEMU test-case! Do we really want to maintain this Frankenstein use case? 1/ Q35 comes with a PCIe bus on which sits a ICH chipset, which already contains a AHCI function exposing multiple IDE buses. What is the point on using an older tech? 2/ Why can we plug a PCI function on a PCIe bridge without using a pcie-pci-bridge?

3/ Chipsets come as a whole. Software drivers might expect all PCI functions working (Linux considering each function individually is not the norm)

But the hardware really looks Frankenstein now: (qemu) info qom-tree /machine (pc-q35-8.0-machine) /peripheral-anon (container) /device[0] (piix3-ide) /bmdma[0] (memory-region) /bmdma[1] (memory-region) /bus master container[0] (memory-region) /bus master[0] (memory-region) /ide.6 (IDE) /ide.7 (IDE) /ide[0] (memory-region) /ide[1] (memory-region) /ide[2] (memory-region) /ide[3] (memory-region) /piix-bmdma-container[0] (memory-region) /piix-bmdma[0] (memory-region) /piix-bmdma[1] (memory-region) /q35 (q35-pcihost) /unattached (container) /device[17] (ich9-ahci) /ahci-idp[0] (memory-region) /ahci[0] (memory-region) /bus master container[0] (memory-region) /bus master[0] (memory-region) /ide.0 (IDE) /ide.1 (IDE) /ide.2 (IDE) /ide.3 (IDE) /ide.4 (IDE) /ide.5 (IDE) /device[2] (ICH9-LPC) /bus master container[0] (memory-region) /bus master[0] (memory-region) /ich9-pm[0] (memory-region) /isa.0 (ISA) I guess the diff [*] is acceptable as a kludge, but we might consider deprecating such use. Paolo, Michael & libvirt folks, what do you think?