2 * This file is part of the Palacios Virtual Machine Monitor developed
3 * by the V3VEE Project with funding from the United States National
4 * Science Foundation and the Department of Energy.
6 * The V3VEE Project is a joint project between Northwestern University
7 * and the University of New Mexico. You can find out more at
10 * Copyright (c) 2008, Jack Lange <jarusl@cs.northwestern.edu>
11 * Copyright (c) 2008, The V3VEE Project <http://www.v3vee.org>
12 * All rights reserved.
14 * Author: Jack Lange <jarusl@cs.northwestern.edu>
16 * This is free software. You are permitted to use,
17 * redistribute, and modify it as specified in the file "V3VEE_LICENSE".
20 #include <palacios/vmm.h>
21 #include <palacios/vmm_dev_mgr.h>
22 #include <devices/lnx_virtio_pci.h>
23 #include <palacios/vm_guest_mem.h>
25 #include <devices/pci.h>
28 #define BLN_REQUESTED_PORT 20
29 #define BLN_ALLOCATED_PORT 28
32 #define PAGE_SIZE 4096
35 struct balloon_config {
36 uint32_t requested_pages;
37 uint32_t allocated_pages;
38 } __attribute__((packed));
43 * A ballooning request is made by specifying the new memory size of the guest. The guest
44 * will then shrink the amount of of memory it uses to target. The target size is stored in the
45 * Virtio PCI configuration space in the requested pages field.
46 * The device raises its irq, to notify the guest
48 * The guest might not be able to shrink to target, so it stores the size it was able to shrink to
49 * into the allocate_pages field of the pci configuration space.
51 * When the guest frees pages it writes the addresses to the deflation queue (the 2nd one),
53 * When pages are given back to the host they are fed in via the inflation queue (the 1st one),
58 #define QUEUE_SIZE 128
60 /* Host Feature flags */
61 #define VIRTIO_NOTIFY_HOST 0x01
64 struct virtio_balloon_state {
65 struct balloon_config balloon_cfg;
66 struct virtio_config virtio_cfg;
68 struct vm_device * pci_bus;
69 struct pci_device * pci_dev;
71 struct virtio_queue queue[2];
74 struct virtio_queue * cur_queue;
80 static int virtio_free(struct vm_device * dev) {
84 static int virtio_reset(struct vm_device * dev) {
85 struct virtio_balloon_state * virtio = (struct virtio_balloon_state *)dev->private_data;
87 memset(virtio->queue, 0, sizeof(struct virtio_queue) * 2);
89 virtio->cur_queue = &(virtio->queue[0]);
92 virtio->virtio_cfg.status = 0;
93 virtio->virtio_cfg.pci_isr = 0;
96 /* Balloon configuration */
97 virtio->virtio_cfg.host_features = VIRTIO_NOTIFY_HOST;
99 // Virtio Balloon uses two queues
100 virtio->queue[0].queue_size = QUEUE_SIZE;
101 virtio->queue[1].queue_size = QUEUE_SIZE;
104 memset(&(virtio->balloon_cfg), 0, sizeof(struct balloon_config));
109 static int get_desc_count(struct virtio_queue * q, int index) {
110 struct vring_desc * tmp_desc = &(q->desc[index]);
113 while (tmp_desc->flags & VIRTIO_NEXT_FLAG) {
114 tmp_desc = &(q->desc[tmp_desc->next]);
122 static int handle_kick(struct guest_info * core, struct vm_device * dev) {
123 struct virtio_balloon_state * virtio = (struct virtio_balloon_state *)dev->private_data;
124 struct virtio_queue * q = virtio->cur_queue;
126 PrintDebug("VIRTIO BALLOON KICK: cur_index=%d (mod=%d), avail_index=%d\n",
127 q->cur_avail_idx, q->cur_avail_idx % QUEUE_SIZE, q->avail->index);
129 while (q->cur_avail_idx < q->avail->index) {
130 struct vring_desc * tmp_desc = NULL;
131 uint16_t desc_idx = q->avail->ring[q->cur_avail_idx % QUEUE_SIZE];
132 int desc_cnt = get_desc_count(q, desc_idx);
134 uint32_t req_len = 0;
137 PrintDebug("Descriptor Count=%d, index=%d\n", desc_cnt, q->cur_avail_idx % QUEUE_SIZE);
139 for (i = 0; i < desc_cnt; i++) {
141 tmp_desc = &(q->desc[desc_idx]);
143 PrintDebug("Header Descriptor (ptr=%p) gpa=%p, len=%d, flags=%x, next=%d\n",
145 (void *)(addr_t)(tmp_desc->addr_gpa), tmp_desc->length,
146 tmp_desc->flags, tmp_desc->next);
149 if (v3_gpa_to_hva(core, tmp_desc->addr_gpa, (addr_t *)&(page_addr)) == -1) {
150 PrintError("Could not translate block header address\n");
155 if (handle_balloon_op(dev, tmp_desc, buf_desc, status_desc) == -1) {
156 PrintError("Error handling balloon operation\n");
161 PrintDebug("Guest Balloon Currently Ignored\n");
162 PrintDebug("\t Requested=%d, Allocated=%d\n",
163 virtio->balloon_cfg.requested_pages,
164 virtio->balloon_cfg.allocated_pages);
166 req_len += tmp_desc->length;
167 desc_idx = tmp_desc->next;
170 q->used->ring[q->used->index % QUEUE_SIZE].id = q->avail->ring[q->cur_avail_idx % QUEUE_SIZE];
171 q->used->ring[q->used->index % QUEUE_SIZE].length = req_len; // What do we set this to????
177 if (!(q->avail->flags & VIRTIO_NO_IRQ_FLAG)) {
178 PrintDebug("Raising IRQ %d\n", virtio->pci_dev->config_header.intr_line);
179 v3_pci_raise_irq(virtio->pci_bus, 0, virtio->pci_dev);
180 virtio->virtio_cfg.pci_isr = VIRTIO_ISR_ACTIVE;
186 static int virtio_io_write(struct guest_info * core, uint16_t port, void * src, uint_t length, void * private_data) {
187 struct vm_device * dev = (struct vm_device *)private_data;
188 struct virtio_balloon_state * virtio = (struct virtio_balloon_state *)dev->private_data;
189 int port_idx = port % virtio->io_range_size;
192 PrintDebug("VIRTIO BALLOON Write for port %d (index=%d) len=%d, value=%x\n",
193 port, port_idx, length, *(uint32_t *)src);
198 case GUEST_FEATURES_PORT:
200 PrintError("Illegal write length for guest features\n");
204 virtio->virtio_cfg.guest_features = *(uint32_t *)src;
207 case VRING_PG_NUM_PORT:
209 addr_t pfn = *(uint32_t *)src;
210 addr_t page_addr = (pfn << VIRTIO_PAGE_SHIFT);
213 virtio->cur_queue->pfn = pfn;
215 virtio->cur_queue->ring_desc_addr = page_addr ;
216 virtio->cur_queue->ring_avail_addr = page_addr + (QUEUE_SIZE * sizeof(struct vring_desc));
217 virtio->cur_queue->ring_used_addr = ( virtio->cur_queue->ring_avail_addr + \
218 sizeof(struct vring_avail) + \
219 (QUEUE_SIZE * sizeof(uint16_t)));
221 // round up to next page boundary.
222 virtio->cur_queue->ring_used_addr = (virtio->cur_queue->ring_used_addr + 0xfff) & ~0xfff;
224 if (v3_gpa_to_hva(core, virtio->cur_queue->ring_desc_addr, (addr_t *)&(virtio->cur_queue->desc)) == -1) {
225 PrintError("Could not translate ring descriptor address\n");
230 if (v3_gpa_to_hva(core, virtio->cur_queue->ring_avail_addr, (addr_t *)&(virtio->cur_queue->avail)) == -1) {
231 PrintError("Could not translate ring available address\n");
236 if (v3_gpa_to_hva(core, virtio->cur_queue->ring_used_addr, (addr_t *)&(virtio->cur_queue->used)) == -1) {
237 PrintError("Could not translate ring used address\n");
241 PrintDebug("RingDesc_addr=%p, Avail_addr=%p, Used_addr=%p\n",
242 (void *)(virtio->cur_queue->ring_desc_addr),
243 (void *)(virtio->cur_queue->ring_avail_addr),
244 (void *)(virtio->cur_queue->ring_used_addr));
246 PrintDebug("RingDesc=%p, Avail=%p, Used=%p\n",
247 virtio->cur_queue->desc, virtio->cur_queue->avail, virtio->cur_queue->used);
250 PrintError("Illegal write length for page frame number\n");
254 case VRING_Q_SEL_PORT:
255 virtio->virtio_cfg.vring_queue_selector = *(uint16_t *)src;
257 if (virtio->virtio_cfg.vring_queue_selector > 1) {
258 PrintError("Virtio Balloon device only uses 2 queue, selected %d\n",
259 virtio->virtio_cfg.vring_queue_selector);
263 virtio->cur_queue = &(virtio->queue[virtio->virtio_cfg.vring_queue_selector]);
266 case VRING_Q_NOTIFY_PORT:
267 PrintDebug("Handling Kick\n");
268 if (handle_kick(core, dev) == -1) {
269 PrintError("Could not handle Balloon Notification\n");
273 case VIRTIO_STATUS_PORT:
274 virtio->virtio_cfg.status = *(uint8_t *)src;
276 if (virtio->virtio_cfg.status == 0) {
277 PrintDebug("Resetting device\n");
283 case VIRTIO_ISR_PORT:
284 virtio->virtio_cfg.pci_isr = *(uint8_t *)src;
295 static int virtio_io_read(struct guest_info * core, uint16_t port, void * dst, uint_t length, void * private_data) {
296 struct vm_device * dev = (struct vm_device *)private_data;
297 struct virtio_balloon_state * virtio = (struct virtio_balloon_state *)dev->private_data;
298 int port_idx = port % virtio->io_range_size;
301 PrintDebug("VIRTIO BALLOON Read for port %d (index =%d), length=%d\n",
302 port, port_idx, length);
305 case HOST_FEATURES_PORT:
307 PrintError("Illegal read length for host features\n");
311 *(uint32_t *)dst = virtio->virtio_cfg.host_features;
314 case VRING_PG_NUM_PORT:
316 PrintError("Illegal read length for page frame number\n");
320 *(uint32_t *)dst = virtio->cur_queue->pfn;
323 case VRING_SIZE_PORT:
325 PrintError("Illegal read length for vring size\n");
329 *(uint16_t *)dst = virtio->cur_queue->queue_size;
333 case VIRTIO_STATUS_PORT:
335 PrintError("Illegal read length for status\n");
339 *(uint8_t *)dst = virtio->virtio_cfg.status;
342 case VIRTIO_ISR_PORT:
343 *(uint8_t *)dst = virtio->virtio_cfg.pci_isr;
344 virtio->virtio_cfg.pci_isr = 0;
345 v3_pci_lower_irq(virtio->pci_bus, 0, virtio->pci_dev);
349 if ( (port_idx >= sizeof(struct virtio_config)) &&
350 (port_idx < (sizeof(struct virtio_config) + sizeof(struct balloon_config))) ) {
351 int cfg_offset = port_idx - sizeof(struct virtio_config);
352 uint8_t * cfg_ptr = (uint8_t *)&(virtio->balloon_cfg);
354 memcpy(dst, cfg_ptr + cfg_offset, length);
357 PrintError("Read of Unhandled Virtio Read\n");
370 static struct v3_device_ops dev_ops = {
378 static int set_size(struct vm_device * dev, addr_t size) {
379 struct virtio_balloon_state * virtio = (struct virtio_balloon_state *)dev->private_data;
381 virtio->balloon_cfg.requested_pages = size / PAGE_SIZE; // number of pages
383 PrintDebug("Requesting %d pages\n", virtio->balloon_cfg.requested_pages);
385 v3_pci_raise_irq(virtio->pci_bus, 0, virtio->pci_dev);
386 virtio->virtio_cfg.pci_isr = VIRTIO_ISR_ACTIVE | VIRTIO_ISR_CFG_CHANGED;
392 static int handle_hcall(struct guest_info * info, uint_t hcall_id, void * priv_data) {
393 struct vm_device * dev = (struct vm_device *)priv_data;
394 int tgt_size = info->vm_regs.rcx;
397 return set_size(dev, tgt_size);
402 static int handle_query_hcall(struct guest_info * info, uint_t hcall_id, void * priv_data) {
403 struct vm_device * dev = (struct vm_device *)priv_data;
404 struct virtio_balloon_state * virtio = (struct virtio_balloon_state *)dev->private_data;
406 info->vm_regs.rcx = virtio->balloon_cfg.requested_pages;
407 info->vm_regs.rdx = virtio->balloon_cfg.allocated_pages;
417 static int virtio_init(struct v3_vm_info * vm, v3_cfg_tree_t * cfg) {
418 struct vm_device * pci_bus = v3_find_dev(vm, v3_cfg_val(cfg, "bus"));
419 struct virtio_balloon_state * virtio_state = NULL;
420 struct pci_device * pci_dev = NULL;
421 char * name = v3_cfg_val(cfg, "name");
423 PrintDebug("Initializing VIRTIO Balloon device\n");
425 if (pci_bus == NULL) {
426 PrintError("VirtIO devices require a PCI Bus");
431 virtio_state = (struct virtio_balloon_state *)V3_Malloc(sizeof(struct virtio_balloon_state));
432 memset(virtio_state, 0, sizeof(struct virtio_balloon_state));
435 struct vm_device * dev = v3_allocate_device(name, &dev_ops, virtio_state);
436 if (v3_attach_device(vm, dev) == -1) {
437 PrintError("Could not attach device %s\n", name);
444 // PCI initialization
446 struct v3_pci_bar bars[6];
447 int num_ports = sizeof(struct virtio_config) + sizeof(struct balloon_config);
448 int tmp_ports = num_ports;
453 // This gets the number of ports, rounded up to a power of 2
454 virtio_state->io_range_size = 1; // must be a power of 2
456 while (tmp_ports > 0) {
458 virtio_state->io_range_size <<= 1;
461 // this is to account for any low order bits being set in num_ports
462 // if there are none, then num_ports was already a power of 2 so we shift right to reset it
463 if ((num_ports & ((virtio_state->io_range_size >> 1) - 1)) == 0) {
464 virtio_state->io_range_size >>= 1;
468 for (i = 0; i < 6; i++) {
469 bars[i].type = PCI_BAR_NONE;
472 bars[0].type = PCI_BAR_IO;
473 bars[0].default_base_port = -1;
474 bars[0].num_ports = virtio_state->io_range_size;
476 bars[0].io_read = virtio_io_read;
477 bars[0].io_write = virtio_io_write;
478 bars[0].private_data = dev;
481 pci_dev = v3_pci_register_device(pci_bus, PCI_STD_DEVICE,
482 0, PCI_AUTO_DEV_NUM, 0,
483 "LNX_VIRTIO_BALLOON", bars,
484 NULL, NULL, NULL, dev);
487 PrintError("Could not register PCI Device\n");
491 pci_dev->config_header.vendor_id = VIRTIO_VENDOR_ID;
492 pci_dev->config_header.subsystem_vendor_id = VIRTIO_SUBVENDOR_ID;
495 pci_dev->config_header.device_id = VIRTIO_BALLOON_DEV_ID;
496 pci_dev->config_header.class = PCI_CLASS_MEMORY;
497 pci_dev->config_header.subclass = PCI_MEM_SUBCLASS_RAM;
499 pci_dev->config_header.subsystem_id = VIRTIO_BALLOON_SUBDEVICE_ID;
502 pci_dev->config_header.intr_pin = 1;
504 pci_dev->config_header.max_latency = 1; // ?? (qemu does it...)
507 virtio_state->pci_dev = pci_dev;
508 virtio_state->pci_bus = pci_bus;
513 v3_register_hypercall(vm, BALLOON_START_HCALL, handle_hcall, dev);
514 v3_register_hypercall(vm, BALLOON_QUERY_HCALL, handle_query_hcall, dev);
520 device_register("LNX_VIRTIO_BALLOON", virtio_init)