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/*
* s390 vfio-pci interfaces
*
* Copyright 2020 IBM Corp.
* Author(s): Matthew Rosato <mjrosato@linux.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or (at
* your option) any later version. See the COPYING file in the top-level
* directory.
*/
#include <sys/ioctl.h>
#include "qemu/osdep.h"
#include "hw/s390x/s390-pci-bus.h"
#include "hw/s390x/s390-pci-vfio.h"
#include "hw/vfio/pci.h"
#include "hw/vfio/vfio-common.h"
/*
* Get the current DMA available count from vfio. Returns true if vfio is
* limiting DMA requests, false otherwise. The current available count read
* from vfio is returned in avail.
*/
bool s390_pci_update_dma_avail(int fd, unsigned int *avail)
{
g_autofree struct vfio_iommu_type1_info *info;
uint32_t argsz;
assert(avail);
argsz = sizeof(struct vfio_iommu_type1_info);
info = g_malloc0(argsz);
/*
* If the specified argsz is not large enough to contain all capabilities
* it will be updated upon return from the ioctl. Retry until we have
* a big enough buffer to hold the entire capability chain.
*/
retry:
info->argsz = argsz;
if (ioctl(fd, VFIO_IOMMU_GET_INFO, info)) {
return false;
}
if (info->argsz > argsz) {
argsz = info->argsz;
info = g_realloc(info, argsz);
goto retry;
}
/* If the capability exists, update with the current value */
return vfio_get_info_dma_avail(info, avail);
}
S390PCIDMACount *s390_pci_start_dma_count(S390pciState *s,
S390PCIBusDevice *pbdev)
{
S390PCIDMACount *cnt;
uint32_t avail;
VFIOPCIDevice *vpdev = container_of(pbdev->pdev, VFIOPCIDevice, pdev);
int id;
assert(vpdev);
id = vpdev->vbasedev.group->container->fd;
if (!s390_pci_update_dma_avail(id, &avail)) {
return NULL;
}
QTAILQ_FOREACH(cnt, &s->zpci_dma_limit, link) {
if (cnt->id == id) {
cnt->users++;
return cnt;
}
}
cnt = g_new0(S390PCIDMACount, 1);
cnt->id = id;
cnt->users = 1;
cnt->avail = avail;
QTAILQ_INSERT_TAIL(&s->zpci_dma_limit, cnt, link);
return cnt;
}
void s390_pci_end_dma_count(S390pciState *s, S390PCIDMACount *cnt)
{
assert(cnt);
cnt->users--;
if (cnt->users == 0) {
QTAILQ_REMOVE(&s->zpci_dma_limit, cnt, link);
}
}
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