From f9bf77dd1f838b0061172fe41709b221956da2f5 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Wed, 25 Nov 2009 15:44:40 +0200 Subject: [PATCH] pci: interrupt status bit implementation interrupt status is a mandatory feature in PCI spec, so devices must implement it to be spec compliant. Signed-off-by: Michael S. Tsirkin Acked-by: Isaku Yamahata --- hw/pci.c | 26 +++++++++++++++++++++++++- hw/pci.h | 1 + 2 files changed, 26 insertions(+), 1 deletion(-) diff --git a/hw/pci.c b/hw/pci.c index a0df618e53..25dbb38bb8 100644 --- a/hw/pci.c +++ b/hw/pci.c @@ -128,11 +128,23 @@ static void pci_change_irq_level(PCIDevice *pci_dev, int irq_num, int change) bus->set_irq(bus->irq_opaque, irq_num, bus->irq_count[irq_num] != 0); } +/* Update interrupt status bit in config space on interrupt + * state change. */ +static void pci_update_irq_status(PCIDevice *dev) +{ + if (dev->irq_state) { + dev->config[PCI_STATUS] |= PCI_STATUS_INTERRUPT; + } else { + dev->config[PCI_STATUS] &= ~PCI_STATUS_INTERRUPT; + } +} + static void pci_device_reset(PCIDevice *dev) { int r; dev->irq_state = 0; + pci_update_irq_status(dev); dev->config[PCI_COMMAND] &= ~(PCI_COMMAND_IO | PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER); dev->config[PCI_CACHE_LINE_SIZE] = 0x0; @@ -377,12 +389,23 @@ static inline const VMStateDescription *pci_get_vmstate(PCIDevice *s) void pci_device_save(PCIDevice *s, QEMUFile *f) { + /* Clear interrupt status bit: it is implicit + * in irq_state which we are saving. + * This makes us compatible with old devices + * which never set or clear this bit. */ + s->config[PCI_STATUS] &= ~PCI_STATUS_INTERRUPT; vmstate_save_state(f, pci_get_vmstate(s), s); + /* Restore the interrupt status bit. */ + pci_update_irq_status(s); } int pci_device_load(PCIDevice *s, QEMUFile *f) { - return vmstate_load_state(f, pci_get_vmstate(s), s, s->version_id); + int ret; + ret = vmstate_load_state(f, pci_get_vmstate(s), s, s->version_id); + /* Restore the interrupt status bit. */ + pci_update_irq_status(s); + return ret; } static int pci_set_default_subsystem_id(PCIDevice *pci_dev) @@ -955,6 +978,7 @@ static void pci_set_irq(void *opaque, int irq_num, int level) return; pci_set_irq_state(pci_dev, irq_num, level); + pci_update_irq_status(pci_dev); pci_change_irq_level(pci_dev, irq_num, change); } diff --git a/hw/pci.h b/hw/pci.h index ebf6c39d52..dc9b8604fe 100644 --- a/hw/pci.h +++ b/hw/pci.h @@ -102,6 +102,7 @@ typedef struct PCIIORegion { #define PCI_COMMAND_MEMORY 0x2 /* Enable response in Memory space */ #define PCI_COMMAND_MASTER 0x4 /* Enable bus master */ #define PCI_STATUS 0x06 /* 16 bits */ +#define PCI_STATUS_INTERRUPT 0x08 #define PCI_REVISION_ID 0x08 /* 8 bits */ #define PCI_CLASS_PROG 0x09 /* Reg. Level Programming Interface */ #define PCI_CLASS_DEVICE 0x0a /* Device class */