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 <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         resgrp->dasm = cap->dasm;
 160         resgrp->msia = cap->msi_addr;
 161         resgrp->mui = cap->mui;
 162         resgrp->i = cap->noi;
 163         resgrp->maxstbl = cap->maxstbl;
 164         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 }