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
34 #define BALLOON_HCALL 0xba00
36 struct balloon_config {
37 uint32_t requested_pages;
38 uint32_t allocated_pages;
39 } __attribute__((packed));
44 * A ballooning request is made by specifying the new memory size of the guest. The guest
45 * will then shrink the amount of of memory it uses to target. The target size is stored in the
46 * Virtio PCI configuration space in the requested pages field. 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), and does a kick.
52 * When pages are given back to the host they are fed in via the inflation queue (the 1st one), and raises an irq.
56 #define QUEUE_SIZE 128
58 /* Host Feature flags */
59 #define VIRTIO_NOTIFY_HOST 0x01
65 struct virtio_balloon_state {
66 struct balloon_config balloon_cfg;
67 struct virtio_config virtio_cfg;
69 struct vm_device * pci_bus;
70 struct pci_device * pci_dev;
72 struct virtio_queue queue[2];
75 struct virtio_queue * cur_queue;
81 static int virtio_free(struct vm_device * dev) {
85 static int virtio_reset(struct vm_device * dev) {
86 struct virtio_balloon_state * virtio = (struct virtio_balloon_state *)dev->private_data;
88 memset(virtio->queue, 0, sizeof(struct virtio_queue) * 2);
90 virtio->cur_queue = &(virtio->queue[0]);
93 virtio->virtio_cfg.status = 0;
94 virtio->virtio_cfg.pci_isr = 0;
97 /* Balloon configuration */
98 virtio->virtio_cfg.host_features = VIRTIO_NOTIFY_HOST;
100 // Virtio Balloon uses two queues
101 virtio->queue[0].queue_size = QUEUE_SIZE;
102 virtio->queue[1].queue_size = QUEUE_SIZE;
105 memset(&(virtio->balloon_cfg), 0, sizeof(struct balloon_config));
113 static int handle_kick(struct vm_device * dev) {
114 struct virtio_balloon_state * virtio = (struct virtio_balloon_state *)dev->private_data;
115 struct virtio_queue * q = virtio->cur_queue;
117 PrintDebug("VIRTIO KICK: cur_index=%d, avail_index=%d\n", q->cur_avail_idx, q->avail->index);
119 while (q->cur_avail_idx < q->avail->index) {
120 struct vring_desc * hdr_desc = NULL;
121 struct vring_desc * buf_desc = NULL;
122 struct vring_desc * status_desc = NULL;
123 uint16_t chain_idx = q->avail->ring[q->cur_avail_idx];
124 uint32_t req_len = 0;
127 PrintDebug("chained=%d, Chain Index=%d\n", chained, chain_idx);
130 hdr_desc = &(q->desc[chain_idx]);
132 PrintDebug("Header Descriptor (ptr=%p) gpa=%p, len=%d, flags=%x, next=%d\n", hdr_desc,
133 (void *)(hdr_desc->addr_gpa), hdr_desc->length, hdr_desc->flags, hdr_desc->next);
135 if (!(hdr_desc->flags & VIRTIO_NEXT_FLAG)) {
136 PrintError("Balloon operations must chain a buffer descriptor\n");
140 buf_desc = &(q->desc[hdr_desc->next]);
142 PrintDebug("Buffer Descriptor (ptr=%p) gpa=%p, len=%d, flags=%x, next=%d\n", buf_desc,
143 (void *)(buf_desc->addr_gpa), buf_desc->length, buf_desc->flags, buf_desc->next);
145 if (!(buf_desc->flags & VIRTIO_NEXT_FLAG)) {
146 PrintError("Balloon operatoins must chain a status descriptor\n");
150 status_desc = &(q->desc[buf_desc->next]);
152 // We detect whether we are chained here...
153 if (status_desc->flags & VIRTIO_NEXT_FLAG) {
155 chain_idx = status_desc->next;
160 PrintDebug("Status Descriptor (ptr=%p) gpa=%p, len=%d, flags=%x, next=%d\n", status_desc,
161 (void *)(status_desc->addr_gpa), status_desc->length, status_desc->flags, status_desc->next);
165 if (handle_balloon_op(dev, hdr_desc, buf_desc, status_desc) == -1) {
166 PrintError("Error handling balloon operation\n");
171 PrintDebug("Guest Balloon Currently Ignored\n");
172 PrintDebug("\t Requested=%d, Allocated=%d\n", virtio->balloon_cfg.requested_pages, virtio->balloon_cfg.allocated_pages);
175 req_len += (buf_desc->length + status_desc->length);
178 q->used->ring[q->used->index].id = q->avail->ring[q->cur_avail_idx];
179 q->used->ring[q->used->index].length = req_len; // What do we set this to????
181 q->used->index = (q->used->index + 1) % (QUEUE_SIZE * sizeof(struct vring_desc));;
184 q->cur_avail_idx = (q->cur_avail_idx + 1) % (QUEUE_SIZE * sizeof(struct vring_desc));
187 if (!(q->avail->flags & VIRTIO_NO_IRQ_FLAG)) {
188 PrintDebug("Raising IRQ %d\n", virtio->pci_dev->config_header.intr_line);
189 v3_pci_raise_irq(virtio->pci_bus, 0, virtio->pci_dev);
190 virtio->virtio_cfg.pci_isr = 1;
196 static int virtio_io_write(uint16_t port, void * src, uint_t length, struct vm_device * dev) {
197 struct virtio_balloon_state * virtio = (struct virtio_balloon_state *)dev->private_data;
198 int port_idx = port % virtio->io_range_size;
201 PrintDebug("VIRTIO BALLOON Write for port %d (index=%d) len=%d, value=%x\n",
202 port, port_idx, length, *(uint32_t *)src);
207 case GUEST_FEATURES_PORT:
209 PrintError("Illegal write length for guest features\n");
213 virtio->virtio_cfg.guest_features = *(uint32_t *)src;
216 case VRING_PG_NUM_PORT:
218 addr_t pfn = *(uint32_t *)src;
219 addr_t page_addr = (pfn << VIRTIO_PAGE_SHIFT);
222 virtio->cur_queue->pfn = pfn;
224 virtio->cur_queue->ring_desc_addr = page_addr ;
225 virtio->cur_queue->ring_avail_addr = page_addr + (QUEUE_SIZE * sizeof(struct vring_desc));
226 virtio->cur_queue->ring_used_addr = ( virtio->cur_queue->ring_avail_addr + \
227 sizeof(struct vring_avail) + \
228 (QUEUE_SIZE * sizeof(uint16_t)));
230 // round up to next page boundary.
231 virtio->cur_queue->ring_used_addr = (virtio->cur_queue->ring_used_addr + 0xfff) & ~0xfff;
233 if (guest_pa_to_host_va(dev->vm, virtio->cur_queue->ring_desc_addr, (addr_t *)&(virtio->cur_queue->desc)) == -1) {
234 PrintError("Could not translate ring descriptor address\n");
239 if (guest_pa_to_host_va(dev->vm, virtio->cur_queue->ring_avail_addr, (addr_t *)&(virtio->cur_queue->avail)) == -1) {
240 PrintError("Could not translate ring available address\n");
245 if (guest_pa_to_host_va(dev->vm, virtio->cur_queue->ring_used_addr, (addr_t *)&(virtio->cur_queue->used)) == -1) {
246 PrintError("Could not translate ring used address\n");
250 PrintDebug("RingDesc_addr=%p, Avail_addr=%p, Used_addr=%p\n",
251 (void *)(virtio->cur_queue->ring_desc_addr),
252 (void *)(virtio->cur_queue->ring_avail_addr),
253 (void *)(virtio->cur_queue->ring_used_addr));
255 PrintDebug("RingDesc=%p, Avail=%p, Used=%p\n",
256 virtio->cur_queue->desc, virtio->cur_queue->avail, virtio->cur_queue->used);
259 PrintError("Illegal write length for page frame number\n");
263 case VRING_Q_SEL_PORT:
264 virtio->virtio_cfg.vring_queue_selector = *(uint16_t *)src;
266 if (virtio->virtio_cfg.vring_queue_selector > 1) {
267 PrintError("Virtio Balloon device only uses 2 queue, selected %d\n",
268 virtio->virtio_cfg.vring_queue_selector);
272 virtio->cur_queue = &(virtio->queue[virtio->virtio_cfg.vring_queue_selector]);
275 case VRING_Q_NOTIFY_PORT:
276 PrintDebug("Handling Kick\n");
277 if (handle_kick(dev) == -1) {
278 PrintError("Could not handle Balloon Notification\n");
282 case VIRTIO_STATUS_PORT:
283 virtio->virtio_cfg.status = *(uint8_t *)src;
285 if (virtio->virtio_cfg.status == 0) {
286 PrintDebug("Resetting device\n");
292 case VIRTIO_ISR_PORT:
293 virtio->virtio_cfg.pci_isr = *(uint8_t *)src;
304 static int virtio_io_read(uint16_t port, void * dst, uint_t length, struct vm_device * dev) {
305 struct virtio_balloon_state * virtio = (struct virtio_balloon_state *)dev->private_data;
306 int port_idx = port % virtio->io_range_size;
309 PrintDebug("VIRTIO BALLOON Read for port %d (index =%d), length=%d\n",
310 port, port_idx, length);
313 case HOST_FEATURES_PORT:
315 PrintError("Illegal read length for host features\n");
319 *(uint32_t *)dst = virtio->virtio_cfg.host_features;
322 case VRING_PG_NUM_PORT:
324 PrintError("Illegal read length for page frame number\n");
328 *(uint32_t *)dst = virtio->cur_queue->pfn;
331 case VRING_SIZE_PORT:
333 PrintError("Illegal read length for vring size\n");
337 *(uint16_t *)dst = virtio->cur_queue->queue_size;
341 case VIRTIO_STATUS_PORT:
343 PrintError("Illegal read length for status\n");
347 *(uint8_t *)dst = virtio->virtio_cfg.status;
350 case VIRTIO_ISR_PORT:
351 *(uint8_t *)dst = virtio->virtio_cfg.pci_isr;
352 virtio->virtio_cfg.pci_isr = 0;
353 v3_pci_lower_irq(virtio->pci_bus, 0, virtio->pci_dev);
357 if ( (port_idx >= sizeof(struct virtio_config)) &&
358 (port_idx < (sizeof(struct virtio_config) + sizeof(struct balloon_config))) ) {
360 uint8_t * cfg_ptr = (uint8_t *)&(virtio->balloon_cfg);
361 memcpy(dst, cfg_ptr, length);
364 PrintError("Read of Unhandled Virtio Read\n");
377 static struct v3_device_ops dev_ops = {
385 static int set_size(struct vm_device * dev, addr_t size) {
386 struct virtio_balloon_state * virtio = (struct virtio_balloon_state *)dev->private_data;
388 virtio->balloon_cfg.requested_pages = size / PAGE_SIZE; // number of pages
389 v3_pci_raise_irq(virtio->pci_bus, 0, virtio->pci_dev);
395 static int handle_hcall(struct guest_info * info, uint_t hcall_id, void * priv_data) {
396 struct vm_device * dev = (struct vm_device *)priv_data;
397 int tgt_size = info->vm_regs.rcx;
400 return set_size(dev, tgt_size);
407 static int virtio_init(struct guest_info * vm, void * cfg_data) {
408 struct vm_device * pci_bus = v3_find_dev(vm, (char *)cfg_data);
409 struct virtio_balloon_state * virtio_state = NULL;
410 struct pci_device * pci_dev = NULL;
412 PrintDebug("Initializing VIRTIO Balloon device\n");
414 if (pci_bus == NULL) {
415 PrintError("VirtIO devices require a PCI Bus");
420 virtio_state = (struct virtio_balloon_state *)V3_Malloc(sizeof(struct virtio_balloon_state));
421 memset(virtio_state, 0, sizeof(struct virtio_balloon_state));
424 struct vm_device * dev = v3_allocate_device("LNX_VIRTIO_BALLOON", &dev_ops, virtio_state);
425 if (v3_attach_device(vm, dev) == -1) {
426 PrintError("Could not attach device %s\n", "LNX_VIRTIO_BALLOON");
433 // PCI initialization
435 struct v3_pci_bar bars[6];
436 int num_ports = sizeof(struct virtio_config) + sizeof(struct balloon_config);
437 int tmp_ports = num_ports;
442 // This gets the number of ports, rounded up to a power of 2
443 virtio_state->io_range_size = 1; // must be a power of 2
445 while (tmp_ports > 0) {
447 virtio_state->io_range_size <<= 1;
450 // this is to account for any low order bits being set in num_ports
451 // if there are none, then num_ports was already a power of 2 so we shift right to reset it
452 if ((num_ports & ((virtio_state->io_range_size >> 1) - 1)) == 0) {
453 virtio_state->io_range_size >>= 1;
457 for (i = 0; i < 6; i++) {
458 bars[i].type = PCI_BAR_NONE;
461 bars[0].type = PCI_BAR_IO;
462 bars[0].default_base_port = -1;
463 bars[0].num_ports = virtio_state->io_range_size;
465 bars[0].io_read = virtio_io_read;
466 bars[0].io_write = virtio_io_write;
468 pci_dev = v3_pci_register_device(pci_bus, PCI_STD_DEVICE,
469 0, PCI_AUTO_DEV_NUM, 0,
470 "LNX_VIRTIO_BALLOON", bars,
471 NULL, NULL, NULL, dev);
474 PrintError("Could not register PCI Device\n");
478 pci_dev->config_header.vendor_id = VIRTIO_VENDOR_ID;
479 pci_dev->config_header.subsystem_vendor_id = VIRTIO_SUBVENDOR_ID;
482 pci_dev->config_header.device_id = VIRTIO_BALLOON_DEV_ID;
483 pci_dev->config_header.class = PCI_CLASS_MEMORY;
484 pci_dev->config_header.subclass = PCI_MEM_SUBCLASS_RAM;
486 pci_dev->config_header.subsystem_id = VIRTIO_BALLOON_SUBDEVICE_ID;
489 pci_dev->config_header.intr_pin = 1;
491 pci_dev->config_header.max_latency = 1; // ?? (qemu does it...)
494 virtio_state->pci_dev = pci_dev;
495 virtio_state->pci_bus = pci_bus;
500 v3_register_hypercall(vm, BALLOON_HCALL, handle_hcall, dev);
506 device_register("LNX_VIRTIO_BALLOON", virtio_init)