hw/s390x/s390-pci-vfio.c

   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  */
  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
  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
  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
 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
 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
 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
 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
 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
 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  */
 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  */
 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 }