From 3927f54a56e29003b84e0e3726d3a0170681128b Mon Sep 17 00:00:00 2001 From: Cornelia Huck Date: Tue, 19 Jan 2021 12:50:44 -0500 Subject: [PATCH 5/7] s390x/pci: Add routine to get the vfio dma available count RH-Author: Cornelia Huck Message-id: <20210119125046.472811-6-cohuck@redhat.com> Patchwork-id: 100679 O-Subject: [RHEL-8.4.0 qemu-kvm PATCH 5/7] s390x/pci: Add routine to get the vfio dma available count Bugzilla: 1905391 RH-Acked-by: David Hildenbrand RH-Acked-by: Auger Eric RH-Acked-by: Thomas Huth From: Matthew Rosato 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 Reviewed-by: Cornelia Huck [aw: Fix non-Linux build with CONFIG_LINUX] Signed-off-by: Alex Williamson (cherry picked from commit cd7498d07fbb20fa04790ff7ee168a8a8d01cb30) Signed-off-by: Cornelia Huck Conflicts: hw/s390x/meson.build --> added the file in hw/s390x/Makefile.objs instead, since we do not use Meson yet hw/s390x/s390-pci-vfio.c --> NULL-initialize "info" to avoid a downstream-only compiler warning Signed-off-by: Danilo C. L. de Paula --- hw/s390x/Makefile.objs | 1 + hw/s390x/s390-pci-vfio.c | 54 ++++++++++++++++++++++++++++++++ include/hw/s390x/s390-pci-vfio.h | 24 ++++++++++++++ 3 files changed, 79 insertions(+) create mode 100644 hw/s390x/s390-pci-vfio.c create mode 100644 include/hw/s390x/s390-pci-vfio.h diff --git a/hw/s390x/Makefile.objs b/hw/s390x/Makefile.objs index c4086ec3171..43756c9437d 100644 --- a/hw/s390x/Makefile.objs +++ b/hw/s390x/Makefile.objs @@ -7,6 +7,7 @@ obj-y += ipl.o obj-y += css.o obj-$(CONFIG_S390_CCW_VIRTIO) += s390-virtio-ccw.o obj-$(CONFIG_TERMINAL3270) += 3270-ccw.o +obj-$(CONFIG_LINUX) += s390-pci-vfio.o ifeq ($(CONFIG_VIRTIO_CCW),y) obj-y += virtio-ccw.o obj-$(CONFIG_VIRTIO_SERIAL) += virtio-ccw-serial.o diff --git a/hw/s390x/s390-pci-vfio.c b/hw/s390x/s390-pci-vfio.c new file mode 100644 index 00000000000..0eb22ffec4c --- /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 + * + * 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 + +#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 = NULL; + 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); +} + diff --git a/include/hw/s390x/s390-pci-vfio.h b/include/hw/s390x/s390-pci-vfio.h new file mode 100644 index 00000000000..1727292e9b5 --- /dev/null +++ b/include/hw/s390x/s390-pci-vfio.h @@ -0,0 +1,24 @@ +/* + * s390 vfio-pci interfaces + * + * Copyright 2020 IBM Corp. + * Author(s): Matthew Rosato + * + * 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. + */ + +#ifndef HW_S390_PCI_VFIO_H +#define HW_S390_PCI_VFIO_H + +#ifdef CONFIG_LINUX +bool s390_pci_update_dma_avail(int fd, unsigned int *avail); +#else +static inline bool s390_pci_update_dma_avail(int fd, unsigned int *avail) +{ + return false; +} +#endif + +#endif -- 2.27.0