xref: /kvmtool/pci.c (revision 70d08766efca03080e262585487cb0f329db5edb)
1 #include "kvm/pci.h"
2 #include "kvm/ioport.h"
3 #include "kvm/util.h"
4 
5 #include <stdint.h>
6 
7 static struct pci_config_address pci_config_address;
8 
9 static bool pci_config_address_out(struct kvm *self, uint16_t port, void *data, int size, uint32_t count)
10 {
11 	struct pci_config_address *addr = data;
12 
13 	pci_config_address	= *addr;
14 
15 	return true;
16 }
17 
18 static bool pci_config_address_in(struct kvm *self, uint16_t port, void *data, int size, uint32_t count)
19 {
20 	struct pci_config_address *addr = data;
21 
22 	*addr		=  pci_config_address;
23 
24 	return true;
25 }
26 
27 static struct ioport_operations pci_config_address_ops = {
28 	.io_in		= pci_config_address_in,
29 	.io_out		= pci_config_address_out,
30 };
31 
32 static bool pci_config_data_out(struct kvm *self, uint16_t port, void *data, int size, uint32_t count)
33 {
34 	return true;
35 }
36 
37 #define PCI_VENDOR_ID_REDHAT_QUMRANET	0x1af4
38 #define PCI_DEVICE_ID_VIRTIO_BLK	0x1001
39 
40 static struct pci_device_header virtio_device = {
41 	.vendor_id		= PCI_VENDOR_ID_REDHAT_QUMRANET,
42 	.device_id		= PCI_DEVICE_ID_VIRTIO_BLK,
43 	.header_type		= PCI_HEADER_TYPE_NORMAL,
44 };
45 
46 static bool pci_device_matches(uint8_t bus_number, uint8_t device_number, uint8_t function_number)
47 {
48 	if (pci_config_address.bus_number != bus_number)
49 		return false;
50 
51 	if (pci_config_address.device_number != device_number)
52 		return false;
53 
54 	return pci_config_address.function_number == function_number;
55 }
56 
57 static bool pci_config_data_in(struct kvm *self, uint16_t port, void *data, int size, uint32_t count)
58 {
59 	unsigned long start;
60 
61 	/*
62 	 * If someone accesses PCI configuration space offsets that are not
63 	 * aligned to 4 bytes, it uses ioports to signify that.
64 	 */
65 	start = port - PCI_CONFIG_DATA;
66 
67 	if (pci_device_matches(0, 1, 0)) {
68 		unsigned long offset;
69 
70 		offset = start + (pci_config_address.register_number << 2);
71 		if (offset < sizeof(struct pci_device_header)) {
72 			void *p = &virtio_device;
73 			memcpy(data, p + offset, size);
74 		} else
75 			memset(data, 0x00, size);
76 	} else
77 		memset(data, 0xff, size);
78 
79 	return true;
80 }
81 
82 static struct ioport_operations pci_config_data_ops = {
83 	.io_in		= pci_config_data_in,
84 	.io_out		= pci_config_data_out,
85 };
86 
87 void pci__init(void)
88 {
89 	ioport__register(PCI_CONFIG_DATA + 0,	&pci_config_data_ops);
90 	ioport__register(PCI_CONFIG_DATA + 1,	&pci_config_data_ops);
91 	ioport__register(PCI_CONFIG_DATA + 2,	&pci_config_data_ops);
92 	ioport__register(PCI_CONFIG_DATA + 3,	&pci_config_data_ops);
93 
94 	ioport__register(PCI_CONFIG_ADDRESS,	&pci_config_address_ops);
95 }
96