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