diff options
author | Matthew Rosato <mjrosato@linux.ibm.com> | 2020-10-26 11:34:34 -0400 |
---|---|---|
committer | Alex Williamson <alex.williamson@redhat.com> | 2020-11-01 12:30:52 -0700 |
commit | cd7498d07fbb20fa04790ff7ee168a8a8d01cb30 (patch) | |
tree | e0ca80da5259ea2faf8e45e729bcd3edf23c443e /hw/s390x/s390-pci-vfio.c | |
parent | 7486a62845b1e12011dd99973e4739f69d57cd38 (diff) |
s390x/pci: Add routine to get the vfio dma available count
Create new files for separating out vfio-specific work for s390
pci. Add the first such routine, which issues VFIO_IOMMU_GET_INFO
ioctl to collect the current dma available count.
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
[aw: Fix non-Linux build with CONFIG_LINUX]
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Diffstat (limited to 'hw/s390x/s390-pci-vfio.c')
-rw-r--r-- | hw/s390x/s390-pci-vfio.c | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/hw/s390x/s390-pci-vfio.c b/hw/s390x/s390-pci-vfio.c new file mode 100644 index 0000000000..cb3f4d98ad --- /dev/null +++ b/hw/s390x/s390-pci-vfio.c @@ -0,0 +1,54 @@ +/* + * 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-vfio.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); +} + |