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     id = vpdev->vbasedev.group->container->fd;
  70
  71     if (!s390_pci_update_dma_avail(id, &avail)) {
  72         return NULL;
  73     }
  74
  75     QTAILQ_FOREACH(cnt, &s->zpci_dma_limit, link) {
  76         if (cnt->id  == id) {
  77             cnt->users++;
  78             return cnt;
  79         }
  80     }
  81
  82     cnt = g_new0(S390PCIDMACount, 1);
  83     cnt->id = id;
  84     cnt->users = 1;
  85     cnt->avail = avail;
  86     QTAILQ_INSERT_TAIL(&s->zpci_dma_limit, cnt, link);
  87     return cnt;
  88 }
  89
  90 void s390_pci_end_dma_count(S390pciState *s, S390PCIDMACount *cnt)
  91 {
  92     assert(cnt);
  93
  94     cnt->users--;
  95     if (cnt->users == 0) {
  96         QTAILQ_REMOVE(&s->zpci_dma_limit, cnt, link);
  97     }
  98 }
  99
 100 static void s390_pci_read_base(S390PCIBusDevice *pbdev,
 101                                struct vfio_device_info *info)
 102 {
 103     struct vfio_info_cap_header *hdr;
 104     struct vfio_device_info_cap_zpci_base *cap;
 105     VFIOPCIDevice *vpci =  container_of(pbdev->pdev, VFIOPCIDevice, pdev);
 106
 107     hdr = vfio_get_device_info_cap(info, VFIO_DEVICE_INFO_CAP_ZPCI_BASE);
 108
 109     /* If capability not provided, just leave the defaults in place */
 110     if (hdr == NULL) {
 111         trace_s390_pci_clp_cap(vpci->vbasedev.name,
 112                                VFIO_DEVICE_INFO_CAP_ZPCI_BASE);
 113         return;
 114     }
 115     cap = (void *) hdr;
 116
 117     pbdev->zpci_fn.sdma = cap->start_dma;
 118     pbdev->zpci_fn.edma = cap->end_dma;
 119     pbdev->zpci_fn.pchid = cap->pchid;
 120     pbdev->zpci_fn.vfn = cap->vfn;
 121     pbdev->zpci_fn.pfgid = cap->gid;
 122     /* The following values remain 0 until we support other FMB formats */
 123     pbdev->zpci_fn.fmbl = 0;
 124     pbdev->zpci_fn.pft = 0;
 125 }
 126
 127 static void s390_pci_read_group(S390PCIBusDevice *pbdev,
 128                                 struct vfio_device_info *info)
 129 {
 130     struct vfio_info_cap_header *hdr;
 131     struct vfio_device_info_cap_zpci_group *cap;
 132     ClpRspQueryPciGrp *resgrp;
 133     VFIOPCIDevice *vpci =  container_of(pbdev->pdev, VFIOPCIDevice, pdev);
 134
 135     hdr = vfio_get_device_info_cap(info, VFIO_DEVICE_INFO_CAP_ZPCI_GROUP);
 136
 137     /* If capability not provided, just use the default group */
 138     if (hdr == NULL) {
 139         trace_s390_pci_clp_cap(vpci->vbasedev.name,
 140                                VFIO_DEVICE_INFO_CAP_ZPCI_GROUP);
 141         pbdev->zpci_fn.pfgid = ZPCI_DEFAULT_FN_GRP;
 142         pbdev->pci_group = s390_group_find(ZPCI_DEFAULT_FN_GRP);
 143         return;
 144     }
 145     cap = (void *) hdr;
 146
 147     /* See if the PCI group is already defined, create if not */
 148     pbdev->pci_group = s390_group_find(pbdev->zpci_fn.pfgid);
 149
 150     if (!pbdev->pci_group) {
 151         pbdev->pci_group = s390_group_create(pbdev->zpci_fn.pfgid);
 152
 153         resgrp = &pbdev->pci_group->zpci_group;
 154         if (cap->flags & VFIO_DEVICE_INFO_ZPCI_FLAG_REFRESH) {
 155             resgrp->fr = 1;
 156         }
 157         resgrp->dasm = cap->dasm;
 158         resgrp->msia = cap->msi_addr;
 159         resgrp->mui = cap->mui;
 160         resgrp->i = cap->noi;
 161         resgrp->maxstbl = cap->maxstbl;
 162         resgrp->version = cap->version;
 163     }
 164 }
 165
 166 static void s390_pci_read_util(S390PCIBusDevice *pbdev,
 167                                struct vfio_device_info *info)
 168 {
 169     struct vfio_info_cap_header *hdr;
 170     struct vfio_device_info_cap_zpci_util *cap;
 171     VFIOPCIDevice *vpci =  container_of(pbdev->pdev, VFIOPCIDevice, pdev);
 172
 173     hdr = vfio_get_device_info_cap(info, VFIO_DEVICE_INFO_CAP_ZPCI_UTIL);
 174
 175     /* If capability not provided, just leave the defaults in place */
 176     if (hdr == NULL) {
 177         trace_s390_pci_clp_cap(vpci->vbasedev.name,
 178                                VFIO_DEVICE_INFO_CAP_ZPCI_UTIL);
 179         return;
 180     }
 181     cap = (void *) hdr;
 182
 183     if (cap->size > CLP_UTIL_STR_LEN) {
 184         trace_s390_pci_clp_cap_size(vpci->vbasedev.name, cap->size,
 185                                     VFIO_DEVICE_INFO_CAP_ZPCI_UTIL);
 186         return;
 187     }
 188
 189     pbdev->zpci_fn.flags |= CLP_RSP_QPCI_MASK_UTIL;
 190     memcpy(pbdev->zpci_fn.util_str, cap->util_str, CLP_UTIL_STR_LEN);
 191 }
 192
 193 static void s390_pci_read_pfip(S390PCIBusDevice *pbdev,
 194                                struct vfio_device_info *info)
 195 {
 196     struct vfio_info_cap_header *hdr;
 197     struct vfio_device_info_cap_zpci_pfip *cap;
 198     VFIOPCIDevice *vpci =  container_of(pbdev->pdev, VFIOPCIDevice, pdev);
 199
 200     hdr = vfio_get_device_info_cap(info, VFIO_DEVICE_INFO_CAP_ZPCI_PFIP);
 201
 202     /* If capability not provided, just leave the defaults in place */
 203     if (hdr == NULL) {
 204         trace_s390_pci_clp_cap(vpci->vbasedev.name,
 205                                VFIO_DEVICE_INFO_CAP_ZPCI_PFIP);
 206         return;
 207     }
 208     cap = (void *) hdr;
 209
 210     if (cap->size > CLP_PFIP_NR_SEGMENTS) {
 211         trace_s390_pci_clp_cap_size(vpci->vbasedev.name, cap->size,
 212                                     VFIO_DEVICE_INFO_CAP_ZPCI_PFIP);
 213         return;
 214     }
 215
 216     memcpy(pbdev->zpci_fn.pfip, cap->pfip, CLP_PFIP_NR_SEGMENTS);
 217 }
 218
 219 /*
 220  * This function will issue the VFIO_DEVICE_GET_INFO ioctl and look for
 221  * capabilities that contain information about CLP features provided by the
 222  * underlying host.
 223  * On entry, defaults have already been placed into the guest CLP response
 224  * buffers.  On exit, defaults will have been overwritten for any CLP features
 225  * found in the capability chain; defaults will remain for any CLP features not
 226  * found in the chain.
 227  */
 228 void s390_pci_get_clp_info(S390PCIBusDevice *pbdev)
 229 {
 230     g_autofree struct vfio_device_info *info = NULL;
 231     VFIOPCIDevice *vfio_pci;
 232     uint32_t argsz;
 233     int fd;
 234
 235     argsz = sizeof(*info);
 236     info = g_malloc0(argsz);
 237
 238     vfio_pci = container_of(pbdev->pdev, VFIOPCIDevice, pdev);
 239     fd = vfio_pci->vbasedev.fd;
 240
 241     /*
 242      * If the specified argsz is not large enough to contain all capabilities
 243      * it will be updated upon return from the ioctl.  Retry until we have
 244      * a big enough buffer to hold the entire capability chain.  On error,
 245      * just exit and rely on CLP defaults.
 246      */
 247 retry:
 248     info->argsz = argsz;
 249
 250     if (ioctl(fd, VFIO_DEVICE_GET_INFO, info)) {
 251         trace_s390_pci_clp_dev_info(vfio_pci->vbasedev.name);
 252         return;
 253     }
 254
 255     if (info->argsz > argsz) {
 256         argsz = info->argsz;
 257         info = g_realloc(info, argsz);
 258         goto retry;
 259     }
 260
 261     /*
 262      * Find the CLP features provided and fill in the guest CLP responses.
 263      * Always call s390_pci_read_base first as information from this could
 264      * determine which function group is used in s390_pci_read_group.
 265      * For any feature not found, the default values will remain in the CLP
 266      * response.
 267      */
 268     s390_pci_read_base(pbdev, info);
 269     s390_pci_read_group(pbdev, info);
 270     s390_pci_read_util(pbdev, info);
 271     s390_pci_read_pfip(pbdev, info);
 272
 273     return;
 274 }