kvm创建虚拟pci设备的几个函数（老版本）

1：

1003 int pci_enable_capability_support(PCIDevice *pci_dev,
1004 uint32_t config_start,
1005 PCICapConfigReadFunc *config_read,
1006 PCICapConfigWriteFunc *config_write,
1007 PCICapConfigInitFunc *config_init)
1008 {
1009 if (!pci_dev)
1010 return -ENODEV;
1011

1012 pci_dev->config[0x06] |= 0x10; // status = capabilities
1013

1014 if (config_start == 0)
1015 pci_dev->cap.start = PCI_CAPABILITY_CONFIG_DEFAULT_START_ADDR;
1016 else if (config_start >= 0x40 && config_start < 0xff)
1017 pci_dev->cap.start = config_start;
1018 else
1019 return -EINVAL;
1020

1021 if (config_read)
1022 pci_dev->cap.config_read = config_read;
1023 else
1024 pci_dev->cap.config_read = pci_default_cap_read_config;
1025 if (config_write)
1026 pci_dev->cap.config_write = config_write;
1027 else
1028 pci_dev->cap.config_write = pci_default_cap_write_config;
1029 pci_dev->cap.supported = 1;
1030 pci_dev->config[PCI_CAPABILITY_LIST] = pci_dev->cap.start;
1031 return config_init(pci_dev);
1032 }

关于irqfd

+#ifdef KVM_CAP_IRQFD
+static int _kvm_irqfd(kvm_context_t kvm, int fd, int gsi, int flags)
+{
+	int r;
+	struct kvm_irqfd data = {
+		.fd    = fd,
+		.gsi   = gsi,
+		.flags = flags,
+	};
+
+	r = ioctl(kvm->vm_fd, KVM_IRQFD, &data);
+	if (r == -1)
+		r = -errno;
+	return r;
+}
+
+int kvm_create_irqfd(kvm_context_t kvm, int gsi, int flags)
+{
+	int r;
+	int fd;
+
+	if (!kvm_check_extension(kvm, KVM_CAP_IRQFD))
+		return -ENOENT;
+
+	fd = eventfd(0, 0);
+	if (fd < 0)
+		return -errno;
+
+	r = _kvm_irqfd(kvm, fd, gsi, 0);
+	if (r < 0) {
+		close(fd);
+		return -errno;
+	}
+
+	return fd;
+}
+
+int kvm_destroy_irqfd(kvm_context_t kvm, int fd, int gsi, int flags)
+{
+	return _kvm_irqfd(kvm, fd, gsi, KVM_IRQFD_FLAG_DEASSIGN);
+}
+
+#else /* KVM_CAP_IRQFD */
+
+int kvm_create_irqfd(kvm_context_t kvm, int gsi, int flags)
+{
+	return -ENOENT;
+}
+
+int kvm_destroy_irqfd(kvm_context_t kvm, int fd, int gsi, int flags)
+{
+	return -ENOENT;
+}
+
+#endif /* KVM_CAP_IRQFD */

+int kvm_assign_iofd(kvm_context_t kvm, unsigned long addr, size_t len,
+		    int fd, int type, int flags)
+{
+	int r;
+	struct kvm_iofd data = {
+		.addr  = addr,
+		.len   = len,
+		.fd    = fd,
+		.flags = type ? KVM_IOFD_FLAG_PIO : 0,
+	};
+
+	if (!kvm_check_extension(kvm, KVM_CAP_EVENTFD))
+		return -ENOENT;
+
+	r = ioctl(kvm->vm_fd, KVM_IOFD, &data);
+	if (r == -1)
+		r = -errno;
+	return r;
+}
+
+int kvm_deassign_iofd(kvm_context_t kvm, unsigned long addr, size_t len,
+		      int type, int flags)
+{
+	int r;
+	struct kvm_iofd data = {
+		.addr  = addr,
+		.len   = len,
+		.flags = KVM_IOFD_FLAG_DEASSIGN | (type ? KVM_IOFD_FLAG_PIO : 0),
+	};
+
+	if (!kvm_check_extension(kvm, KVM_CAP_EVENTFD))
+		return -ENOENT;
+
+	r = ioctl(kvm->vm_fd, KVM_IOFD, &data);
+	if (r == -1)
+		r = -errno;
+	return r;
+}
+
#else /* KVM_CAP_EVENTFD */