1 /*
2 * s390 vfio-pci interfaces
3 *
4 * Copyright 2020 IBM Corp.
5 * Author(s): Matthew Rosato <mjrosato@linux.ibm.com>
6 *
7 * This work is licensed under the terms of the GNU GPL, version 2 or (at
8 * your option) any later version. See the COPYING file in the top-level
9 * directory.
10 */
11
12 #include "qemu/osdep.h"
13
14 #include <sys/ioctl.h>
15 #include <linux/vfio.h>
16 #include <linux/vfio_zdev.h>
17
18 #include "trace.h"
19 #include "hw/s390x/s390-pci-bus.h"
20 #include "hw/s390x/s390-pci-clp.h"
21 #include "hw/s390x/s390-pci-vfio.h"
22 #include "hw/vfio/pci.h"
23 #include "hw/vfio/vfio-common.h"
24
25 /*
26 * Get the current DMA available count from vfio. Returns true if vfio is
27 * limiting DMA requests, false otherwise. The current available count read
28 * from vfio is returned in avail.
29 */
s390_pci_update_dma_avail(int fd,unsigned int * avail)30 bool s390_pci_update_dma_avail(int fd, unsigned int *avail)
31 {
32 uint32_t argsz = sizeof(struct vfio_iommu_type1_info);
33 g_autofree struct vfio_iommu_type1_info *info = g_malloc0(argsz);
34
35 assert(avail);
36
37 /*
38 * If the specified argsz is not large enough to contain all capabilities
39 * it will be updated upon return from the ioctl. Retry until we have
40 * a big enough buffer to hold the entire capability chain.
41 */
42 retry:
43 info->argsz = argsz;
44
45 if (ioctl(fd, VFIO_IOMMU_GET_INFO, info)) {
46 return false;
47 }
48
49 if (info->argsz > argsz) {
50 argsz = info->argsz;
51 info = g_realloc(info, argsz);
52 goto retry;
53 }
54
55 /* If the capability exists, update with the current value */
56 return vfio_get_info_dma_avail(info, avail);
57 }
58
s390_pci_start_dma_count(S390pciState * s,S390PCIBusDevice * pbdev)59 S390PCIDMACount *s390_pci_start_dma_count(S390pciState *s,
60 S390PCIBusDevice *pbdev)
61 {
62 S390PCIDMACount *cnt;
63 uint32_t avail;
64 VFIOPCIDevice *vpdev = container_of(pbdev->pdev, VFIOPCIDevice, pdev);
65 int id;
66
67 assert(vpdev);
68
69 if (!vpdev->vbasedev.group) {
70 return NULL;
71 }
72
73 id = vpdev->vbasedev.group->container->fd;
74
75 if (!s390_pci_update_dma_avail(id, &avail)) {
76 return NULL;
77 }
78
79 QTAILQ_FOREACH(cnt, &s->zpci_dma_limit, link) {
80 if (cnt->id == id) {
81 cnt->users++;
82 return cnt;
83 }
84 }
85
86 cnt = g_new0(S390PCIDMACount, 1);
87 cnt->id = id;
88 cnt->users = 1;
89 cnt->avail = avail;
90 QTAILQ_INSERT_TAIL(&s->zpci_dma_limit, cnt, link);
91 pbdev->iommu->max_dma_limit = avail;
92 return cnt;
93 }
94
s390_pci_end_dma_count(S390pciState * s,S390PCIDMACount * cnt)95 void s390_pci_end_dma_count(S390pciState *s, S390PCIDMACount *cnt)
96 {
97 assert(cnt);
98
99 cnt->users--;
100 if (cnt->users == 0) {
101 QTAILQ_REMOVE(&s->zpci_dma_limit, cnt, link);
102 }
103 }
104
s390_pci_read_base(S390PCIBusDevice * pbdev,struct vfio_device_info * info)105 static void s390_pci_read_base(S390PCIBusDevice *pbdev,
106 struct vfio_device_info *info)
107 {
108 struct vfio_info_cap_header *hdr;
109 struct vfio_device_info_cap_zpci_base *cap;
110 VFIOPCIDevice *vpci = container_of(pbdev->pdev, VFIOPCIDevice, pdev);
111 uint64_t vfio_size;
112
113 hdr = vfio_get_device_info_cap(info, VFIO_DEVICE_INFO_CAP_ZPCI_BASE);
114
115 /* If capability not provided, just leave the defaults in place */
116 if (hdr == NULL) {
117 trace_s390_pci_clp_cap(vpci->vbasedev.name,
118 VFIO_DEVICE_INFO_CAP_ZPCI_BASE);
119 return;
120 }
121 cap = (void *) hdr;
122
123 pbdev->zpci_fn.sdma = cap->start_dma;
124 pbdev->zpci_fn.edma = cap->end_dma;
125 pbdev->zpci_fn.pchid = cap->pchid;
126 pbdev->zpci_fn.vfn = cap->vfn;
127 pbdev->zpci_fn.pfgid = cap->gid;
128 /* The following values remain 0 until we support other FMB formats */
129 pbdev->zpci_fn.fmbl = 0;
130 pbdev->zpci_fn.pft = 0;
131 /* Store function type separately for type-specific behavior */
132 pbdev->pft = cap->pft;
133
134 /*
135 * If appropriate, reduce the size of the supported DMA aperture reported
136 * to the guest based upon the vfio DMA limit.
137 */
138 vfio_size = pbdev->iommu->max_dma_limit << TARGET_PAGE_BITS;
139 if (vfio_size > 0 && vfio_size < cap->end_dma - cap->start_dma + 1) {
140 pbdev->zpci_fn.edma = cap->start_dma + vfio_size - 1;
141 }
142 }
143
get_host_fh(S390PCIBusDevice * pbdev,struct vfio_device_info * info,uint32_t * fh)144 static bool get_host_fh(S390PCIBusDevice *pbdev, struct vfio_device_info *info,
145 uint32_t *fh)
146 {
147 struct vfio_info_cap_header *hdr;
148 struct vfio_device_info_cap_zpci_base *cap;
149 VFIOPCIDevice *vpci = container_of(pbdev->pdev, VFIOPCIDevice, pdev);
150
151 hdr = vfio_get_device_info_cap(info, VFIO_DEVICE_INFO_CAP_ZPCI_BASE);
152
153 /* Can only get the host fh with version 2 or greater */
154 if (hdr == NULL || hdr->version < 2) {
155 trace_s390_pci_clp_cap(vpci->vbasedev.name,
156 VFIO_DEVICE_INFO_CAP_ZPCI_BASE);
157 return false;
158 }
159 cap = (void *) hdr;
160
161 *fh = cap->fh;
162 return true;
163 }
164
s390_pci_read_group(S390PCIBusDevice * pbdev,struct vfio_device_info * info)165 static void s390_pci_read_group(S390PCIBusDevice *pbdev,
166 struct vfio_device_info *info)
167 {
168 struct vfio_info_cap_header *hdr;
169 struct vfio_device_info_cap_zpci_group *cap;
170 S390pciState *s = s390_get_phb();
171 ClpRspQueryPciGrp *resgrp;
172 VFIOPCIDevice *vpci = container_of(pbdev->pdev, VFIOPCIDevice, pdev);
173 uint8_t start_gid = pbdev->zpci_fn.pfgid;
174
175 hdr = vfio_get_device_info_cap(info, VFIO_DEVICE_INFO_CAP_ZPCI_GROUP);
176
177 /*
178 * If capability not provided or the underlying hostdev is simulated, just
179 * use the default group.
180 */
181 if (hdr == NULL || pbdev->zpci_fn.pfgid >= ZPCI_SIM_GRP_START) {
182 trace_s390_pci_clp_cap(vpci->vbasedev.name,
183 VFIO_DEVICE_INFO_CAP_ZPCI_GROUP);
184 pbdev->zpci_fn.pfgid = ZPCI_DEFAULT_FN_GRP;
185 pbdev->pci_group = s390_group_find(ZPCI_DEFAULT_FN_GRP);
186 return;
187 }
188 cap = (void *) hdr;
189
190 /*
191 * For an intercept device, let's use an existing simulated group if one
192 * one was already created for other intercept devices in this group.
193 * If not, create a new simulated group if any are still available.
194 * If all else fails, just fall back on the default group.
195 */
196 if (!pbdev->interp) {
197 pbdev->pci_group = s390_group_find_host_sim(pbdev->zpci_fn.pfgid);
198 if (pbdev->pci_group) {
199 /* Use existing simulated group */
200 pbdev->zpci_fn.pfgid = pbdev->pci_group->id;
201 return;
202 } else {
203 if (s->next_sim_grp == ZPCI_DEFAULT_FN_GRP) {
204 /* All out of simulated groups, use default */
205 trace_s390_pci_clp_cap(vpci->vbasedev.name,
206 VFIO_DEVICE_INFO_CAP_ZPCI_GROUP);
207 pbdev->zpci_fn.pfgid = ZPCI_DEFAULT_FN_GRP;
208 pbdev->pci_group = s390_group_find(ZPCI_DEFAULT_FN_GRP);
209 return;
210 } else {
211 /* We can assign a new simulated group */
212 pbdev->zpci_fn.pfgid = s->next_sim_grp;
213 s->next_sim_grp++;
214 /* Fall through to create the new sim group using CLP info */
215 }
216 }
217 }
218
219 /* See if the PCI group is already defined, create if not */
220 pbdev->pci_group = s390_group_find(pbdev->zpci_fn.pfgid);
221
222 if (!pbdev->pci_group) {
223 pbdev->pci_group = s390_group_create(pbdev->zpci_fn.pfgid, start_gid);
224
225 resgrp = &pbdev->pci_group->zpci_group;
226 if (cap->flags & VFIO_DEVICE_INFO_ZPCI_FLAG_REFRESH) {
227 resgrp->fr = 1;
228 }
229 resgrp->dasm = cap->dasm;
230 resgrp->msia = cap->msi_addr;
231 resgrp->mui = cap->mui;
232 resgrp->i = cap->noi;
233 if (pbdev->interp && hdr->version >= 2) {
234 resgrp->maxstbl = cap->imaxstbl;
235 } else {
236 resgrp->maxstbl = cap->maxstbl;
237 }
238 resgrp->version = cap->version;
239 resgrp->dtsm = ZPCI_DTSM;
240 }
241 }
242
s390_pci_read_util(S390PCIBusDevice * pbdev,struct vfio_device_info * info)243 static void s390_pci_read_util(S390PCIBusDevice *pbdev,
244 struct vfio_device_info *info)
245 {
246 struct vfio_info_cap_header *hdr;
247 struct vfio_device_info_cap_zpci_util *cap;
248 VFIOPCIDevice *vpci = container_of(pbdev->pdev, VFIOPCIDevice, pdev);
249
250 hdr = vfio_get_device_info_cap(info, VFIO_DEVICE_INFO_CAP_ZPCI_UTIL);
251
252 /* If capability not provided, just leave the defaults in place */
253 if (hdr == NULL) {
254 trace_s390_pci_clp_cap(vpci->vbasedev.name,
255 VFIO_DEVICE_INFO_CAP_ZPCI_UTIL);
256 return;
257 }
258 cap = (void *) hdr;
259
260 if (cap->size > CLP_UTIL_STR_LEN) {
261 trace_s390_pci_clp_cap_size(vpci->vbasedev.name, cap->size,
262 VFIO_DEVICE_INFO_CAP_ZPCI_UTIL);
263 return;
264 }
265
266 pbdev->zpci_fn.flags |= CLP_RSP_QPCI_MASK_UTIL;
267 memcpy(pbdev->zpci_fn.util_str, cap->util_str, CLP_UTIL_STR_LEN);
268 }
269
s390_pci_read_pfip(S390PCIBusDevice * pbdev,struct vfio_device_info * info)270 static void s390_pci_read_pfip(S390PCIBusDevice *pbdev,
271 struct vfio_device_info *info)
272 {
273 struct vfio_info_cap_header *hdr;
274 struct vfio_device_info_cap_zpci_pfip *cap;
275 VFIOPCIDevice *vpci = container_of(pbdev->pdev, VFIOPCIDevice, pdev);
276
277 hdr = vfio_get_device_info_cap(info, VFIO_DEVICE_INFO_CAP_ZPCI_PFIP);
278
279 /* If capability not provided, just leave the defaults in place */
280 if (hdr == NULL) {
281 trace_s390_pci_clp_cap(vpci->vbasedev.name,
282 VFIO_DEVICE_INFO_CAP_ZPCI_PFIP);
283 return;
284 }
285 cap = (void *) hdr;
286
287 if (cap->size > CLP_PFIP_NR_SEGMENTS) {
288 trace_s390_pci_clp_cap_size(vpci->vbasedev.name, cap->size,
289 VFIO_DEVICE_INFO_CAP_ZPCI_PFIP);
290 return;
291 }
292
293 memcpy(pbdev->zpci_fn.pfip, cap->pfip, CLP_PFIP_NR_SEGMENTS);
294 }
295
get_device_info(S390PCIBusDevice * pbdev)296 static struct vfio_device_info *get_device_info(S390PCIBusDevice *pbdev)
297 {
298 VFIOPCIDevice *vfio_pci = container_of(pbdev->pdev, VFIOPCIDevice, pdev);
299
300 return vfio_get_device_info(vfio_pci->vbasedev.fd);
301 }
302
303 /*
304 * Get the host function handle from the vfio CLP capabilities chain. Returns
305 * true if a fh value was placed into the provided buffer. Returns false
306 * if a fh could not be obtained (ioctl failed or capability version does
307 * not include the fh)
308 */
s390_pci_get_host_fh(S390PCIBusDevice * pbdev,uint32_t * fh)309 bool s390_pci_get_host_fh(S390PCIBusDevice *pbdev, uint32_t *fh)
310 {
311 g_autofree struct vfio_device_info *info = NULL;
312
313 assert(fh);
314
315 info = get_device_info(pbdev);
316 if (!info) {
317 return false;
318 }
319
320 return get_host_fh(pbdev, info, fh);
321 }
322
323 /*
324 * This function will issue the VFIO_DEVICE_GET_INFO ioctl and look for
325 * capabilities that contain information about CLP features provided by the
326 * underlying host.
327 * On entry, defaults have already been placed into the guest CLP response
328 * buffers. On exit, defaults will have been overwritten for any CLP features
329 * found in the capability chain; defaults will remain for any CLP features not
330 * found in the chain.
331 */
s390_pci_get_clp_info(S390PCIBusDevice * pbdev)332 void s390_pci_get_clp_info(S390PCIBusDevice *pbdev)
333 {
334 g_autofree struct vfio_device_info *info = NULL;
335
336 info = get_device_info(pbdev);
337 if (!info) {
338 return;
339 }
340
341 /*
342 * Find the CLP features provided and fill in the guest CLP responses.
343 * Always call s390_pci_read_base first as information from this could
344 * determine which function group is used in s390_pci_read_group.
345 * For any feature not found, the default values will remain in the CLP
346 * response.
347 */
348 s390_pci_read_base(pbdev, info);
349 s390_pci_read_group(pbdev, info);
350 s390_pci_read_util(pbdev, info);
351 s390_pci_read_pfip(pbdev, info);
352
353 return;
354 }
355