xref: /openbmc/qemu/hw/s390x/s390-pci-vfio.c (revision 57b3a7d8) 
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 <sys/ioctl.h>
13 #include <linux/vfio.h>
14 #include <linux/vfio_zdev.h>
15 
16 #include "qemu/osdep.h"
17 #include "trace.h"
18 #include "hw/s390x/s390-pci-bus.h"
19 #include "hw/s390x/s390-pci-clp.h"
20 #include "hw/s390x/s390-pci-vfio.h"
21 #include "hw/vfio/pci.h"
22 #include "hw/vfio/vfio-common.h"
23 
24 /*
25  * Get the current DMA available count from vfio.  Returns true if vfio is
26  * limiting DMA requests, false otherwise.  The current available count read
27  * from vfio is returned in avail.
28  */
29 bool s390_pci_update_dma_avail(int fd, unsigned int *avail)
30 {
31     g_autofree struct vfio_iommu_type1_info *info;
32     uint32_t argsz;
33 
34     assert(avail);
35 
36     argsz = sizeof(struct vfio_iommu_type1_info);
37     info = g_malloc0(argsz);
38 
39     /*
40      * If the specified argsz is not large enough to contain all capabilities
41      * it will be updated upon return from the ioctl.  Retry until we have
42      * a big enough buffer to hold the entire capability chain.
43      */
44 retry:
45     info->argsz = argsz;
46 
47     if (ioctl(fd, VFIO_IOMMU_GET_INFO, info)) {
48         return false;
49     }
50 
51     if (info->argsz > argsz) {
52         argsz = info->argsz;
53         info = g_realloc(info, argsz);
54         goto retry;
55     }
56 
57     /* If the capability exists, update with the current value */
58     return vfio_get_info_dma_avail(info, avail);
59 }
60 
61 S390PCIDMACount *s390_pci_start_dma_count(S390pciState *s,
62                                           S390PCIBusDevice *pbdev)
63 {
64     S390PCIDMACount *cnt;
65     uint32_t avail;
66     VFIOPCIDevice *vpdev = container_of(pbdev->pdev, VFIOPCIDevice, pdev);
67     int id;
68 
69     assert(vpdev);
70 
71     id = vpdev->vbasedev.group->container->fd;
72 
73     if (!s390_pci_update_dma_avail(id, &avail)) {
74         return NULL;
75     }
76 
77     QTAILQ_FOREACH(cnt, &s->zpci_dma_limit, link) {
78         if (cnt->id  == id) {
79             cnt->users++;
80             return cnt;
81         }
82     }
83 
84     cnt = g_new0(S390PCIDMACount, 1);
85     cnt->id = id;
86     cnt->users = 1;
87     cnt->avail = avail;
88     QTAILQ_INSERT_TAIL(&s->zpci_dma_limit, cnt, link);
89     return cnt;
90 }
91 
92 void s390_pci_end_dma_count(S390pciState *s, S390PCIDMACount *cnt)
93 {
94     assert(cnt);
95 
96     cnt->users--;
97     if (cnt->users == 0) {
98         QTAILQ_REMOVE(&s->zpci_dma_limit, cnt, link);
99     }
100 }
101 
102 static void s390_pci_read_base(S390PCIBusDevice *pbdev,
103                                struct vfio_device_info *info)
104 {
105     struct vfio_info_cap_header *hdr;
106     struct vfio_device_info_cap_zpci_base *cap;
107     VFIOPCIDevice *vpci =  container_of(pbdev->pdev, VFIOPCIDevice, pdev);
108 
109     hdr = vfio_get_device_info_cap(info, VFIO_DEVICE_INFO_CAP_ZPCI_BASE);
110 
111     /* If capability not provided, just leave the defaults in place */
112     if (hdr == NULL) {
113         trace_s390_pci_clp_cap(vpci->vbasedev.name,
114                                VFIO_DEVICE_INFO_CAP_ZPCI_BASE);
115         return;
116     }
117     cap = (void *) hdr;
118 
119     pbdev->zpci_fn.sdma = cap->start_dma;
120     pbdev->zpci_fn.edma = cap->end_dma;
121     pbdev->zpci_fn.pchid = cap->pchid;
122     pbdev->zpci_fn.vfn = cap->vfn;
123     pbdev->zpci_fn.pfgid = cap->gid;
124     /* The following values remain 0 until we support other FMB formats */
125     pbdev->zpci_fn.fmbl = 0;
126     pbdev->zpci_fn.pft = 0;
127 }
128 
129 static void s390_pci_read_group(S390PCIBusDevice *pbdev,
130                                 struct vfio_device_info *info)
131 {
132     struct vfio_info_cap_header *hdr;
133     struct vfio_device_info_cap_zpci_group *cap;
134     ClpRspQueryPciGrp *resgrp;
135     VFIOPCIDevice *vpci =  container_of(pbdev->pdev, VFIOPCIDevice, pdev);
136 
137     hdr = vfio_get_device_info_cap(info, VFIO_DEVICE_INFO_CAP_ZPCI_GROUP);
138 
139     /* If capability not provided, just use the default group */
140     if (hdr == NULL) {
141         trace_s390_pci_clp_cap(vpci->vbasedev.name,
142                                VFIO_DEVICE_INFO_CAP_ZPCI_GROUP);
143         pbdev->zpci_fn.pfgid = ZPCI_DEFAULT_FN_GRP;
144         pbdev->pci_group = s390_group_find(ZPCI_DEFAULT_FN_GRP);
145         return;
146     }
147     cap = (void *) hdr;
148 
149     /* See if the PCI group is already defined, create if not */
150     pbdev->pci_group = s390_group_find(pbdev->zpci_fn.pfgid);
151 
152     if (!pbdev->pci_group) {
153         pbdev->pci_group = s390_group_create(pbdev->zpci_fn.pfgid);
154 
155         resgrp = &pbdev->pci_group->zpci_group;
156         if (cap->flags & VFIO_DEVICE_INFO_ZPCI_FLAG_REFRESH) {
157             resgrp->fr = 1;
158         }
159         stq_p(&resgrp->dasm, cap->dasm);
160         stq_p(&resgrp->msia, cap->msi_addr);
161         stw_p(&resgrp->mui, cap->mui);
162         stw_p(&resgrp->i, cap->noi);
163         stw_p(&resgrp->maxstbl, cap->maxstbl);
164         stb_p(&resgrp->version, cap->version);
165     }
166 }
167 
168 static void s390_pci_read_util(S390PCIBusDevice *pbdev,
169                                struct vfio_device_info *info)
170 {
171     struct vfio_info_cap_header *hdr;
172     struct vfio_device_info_cap_zpci_util *cap;
173     VFIOPCIDevice *vpci =  container_of(pbdev->pdev, VFIOPCIDevice, pdev);
174 
175     hdr = vfio_get_device_info_cap(info, VFIO_DEVICE_INFO_CAP_ZPCI_UTIL);
176 
177     /* If capability not provided, just leave the defaults in place */
178     if (hdr == NULL) {
179         trace_s390_pci_clp_cap(vpci->vbasedev.name,
180                                VFIO_DEVICE_INFO_CAP_ZPCI_UTIL);
181         return;
182     }
183     cap = (void *) hdr;
184 
185     if (cap->size > CLP_UTIL_STR_LEN) {
186         trace_s390_pci_clp_cap_size(vpci->vbasedev.name, cap->size,
187                                     VFIO_DEVICE_INFO_CAP_ZPCI_UTIL);
188         return;
189     }
190 
191     pbdev->zpci_fn.flags |= CLP_RSP_QPCI_MASK_UTIL;
192     memcpy(pbdev->zpci_fn.util_str, cap->util_str, CLP_UTIL_STR_LEN);
193 }
194 
195 static void s390_pci_read_pfip(S390PCIBusDevice *pbdev,
196                                struct vfio_device_info *info)
197 {
198     struct vfio_info_cap_header *hdr;
199     struct vfio_device_info_cap_zpci_pfip *cap;
200     VFIOPCIDevice *vpci =  container_of(pbdev->pdev, VFIOPCIDevice, pdev);
201 
202     hdr = vfio_get_device_info_cap(info, VFIO_DEVICE_INFO_CAP_ZPCI_PFIP);
203 
204     /* If capability not provided, just leave the defaults in place */
205     if (hdr == NULL) {
206         trace_s390_pci_clp_cap(vpci->vbasedev.name,
207                                VFIO_DEVICE_INFO_CAP_ZPCI_PFIP);
208         return;
209     }
210     cap = (void *) hdr;
211 
212     if (cap->size > CLP_PFIP_NR_SEGMENTS) {
213         trace_s390_pci_clp_cap_size(vpci->vbasedev.name, cap->size,
214                                     VFIO_DEVICE_INFO_CAP_ZPCI_PFIP);
215         return;
216     }
217 
218     memcpy(pbdev->zpci_fn.pfip, cap->pfip, CLP_PFIP_NR_SEGMENTS);
219 }
220 
221 /*
222  * This function will issue the VFIO_DEVICE_GET_INFO ioctl and look for
223  * capabilities that contain information about CLP features provided by the
224  * underlying host.
225  * On entry, defaults have already been placed into the guest CLP response
226  * buffers.  On exit, defaults will have been overwritten for any CLP features
227  * found in the capability chain; defaults will remain for any CLP features not
228  * found in the chain.
229  */
230 void s390_pci_get_clp_info(S390PCIBusDevice *pbdev)
231 {
232     g_autofree struct vfio_device_info *info;
233     VFIOPCIDevice *vfio_pci;
234     uint32_t argsz;
235     int fd;
236 
237     argsz = sizeof(*info);
238     info = g_malloc0(argsz);
239 
240     vfio_pci = container_of(pbdev->pdev, VFIOPCIDevice, pdev);
241     fd = vfio_pci->vbasedev.fd;
242 
243     /*
244      * If the specified argsz is not large enough to contain all capabilities
245      * it will be updated upon return from the ioctl.  Retry until we have
246      * a big enough buffer to hold the entire capability chain.  On error,
247      * just exit and rely on CLP defaults.
248      */
249 retry:
250     info->argsz = argsz;
251 
252     if (ioctl(fd, VFIO_DEVICE_GET_INFO, info)) {
253         trace_s390_pci_clp_dev_info(vfio_pci->vbasedev.name);
254         return;
255     }
256 
257     if (info->argsz > argsz) {
258         argsz = info->argsz;
259         info = g_realloc(info, argsz);
260         goto retry;
261     }
262 
263     /*
264      * Find the CLP features provided and fill in the guest CLP responses.
265      * Always call s390_pci_read_base first as information from this could
266      * determine which function group is used in s390_pci_read_group.
267      * For any feature not found, the default values will remain in the CLP
268      * response.
269      */
270     s390_pci_read_base(pbdev, info);
271     s390_pci_read_group(pbdev, info);
272     s390_pci_read_util(pbdev, info);
273     s390_pci_read_pfip(pbdev, info);
274 
275     return;
276 }
277