From 2fdadd02e675caca4aba4ae26317701fe2c4c901 Mon Sep 17 00:00:00 2001 From: BALATON Zoltan Date: Thu, 16 Feb 2023 21:21:35 +0100 Subject: [PATCH] hw/isa/vt82c686: Implement PCI IRQ routing MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The real VIA south bridges implement a PCI IRQ router which is configured by the BIOS or the OS. In order to respect these configurations, QEMU needs to implement it as well. The real chip may allow routing IRQs from internal functions independently of PCI interrupts but since guests usually configute it to a single shared interrupt we don't model that here for simplicity. Note: The implementation was taken from piix4_set_irq() in hw/isa/piix4. Suggested-by: Bernhard Beschow Signed-off-by: BALATON Zoltan Reviewed-by: Bernhard Beschow Tested-by: Rene Engel Message-Id: Signed-off-by: Philippe Mathieu-Daudé --- hw/isa/vt82c686.c | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) diff --git a/hw/isa/vt82c686.c b/hw/isa/vt82c686.c index 01e0148967..71da316052 100644 --- a/hw/isa/vt82c686.c +++ b/hw/isa/vt82c686.c @@ -604,6 +604,46 @@ static void via_isa_request_i8259_irq(void *opaque, int irq, int level) qemu_set_irq(s->cpu_intr, level); } +static int via_isa_get_pci_irq(const ViaISAState *s, int irq_num) +{ + switch (irq_num) { + case 0: + return s->dev.config[0x55] >> 4; + case 1: + return s->dev.config[0x56] & 0xf; + case 2: + return s->dev.config[0x56] >> 4; + case 3: + return s->dev.config[0x57] >> 4; + } + return 0; +} + +static void via_isa_set_pci_irq(void *opaque, int irq_num, int level) +{ + ViaISAState *s = opaque; + PCIBus *bus = pci_get_bus(&s->dev); + int i, pic_level, pic_irq = via_isa_get_pci_irq(s, irq_num); + + /* IRQ 0: disabled, IRQ 2,8,13: reserved */ + if (!pic_irq) { + return; + } + if (unlikely(pic_irq == 2 || pic_irq == 8 || pic_irq == 13)) { + qemu_log_mask(LOG_GUEST_ERROR, "Invalid ISA IRQ routing"); + } + + /* The pic level is the logical OR of all the PCI irqs mapped to it. */ + pic_level = 0; + for (i = 0; i < PCI_NUM_PINS; i++) { + if (pic_irq == via_isa_get_pci_irq(s, i)) { + pic_level |= pci_bus_get_irq_level(bus, i); + } + } + /* Now we change the pic irq level according to the via irq mappings. */ + qemu_set_irq(s->isa_irqs_in[pic_irq], pic_level); +} + static void via_isa_realize(PCIDevice *d, Error **errp) { ViaISAState *s = VIA_ISA(d); @@ -627,6 +667,8 @@ static void via_isa_realize(PCIDevice *d, Error **errp) i8254_pit_init(isa_bus, 0x40, 0, NULL); i8257_dma_init(isa_bus, 0); + qdev_init_gpio_in_named(dev, via_isa_set_pci_irq, "pirq", PCI_NUM_PINS); + /* RTC */ qdev_prop_set_int32(DEVICE(&s->rtc), "base_year", 2000); if (!qdev_realize(DEVICE(&s->rtc), BUS(isa_bus), errp)) {