@@ -10,6 +10,7 @@ s390x_ss.add(files(
's390-ccw.c',
's390-pci-bus.c',
's390-pci-inst.c',
+ 's390-pci-vfio.c',
's390-skeys.c',
's390-stattrib.c',
's390-virtio-hcall.c',
new file mode 100644
@@ -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 "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);
+}
+
new file mode 100644
@@ -0,0 +1,17 @@
+/*
+ * 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.
+ */
+
+#ifndef HW_S390_PCI_VFIO_H
+#define HW_S390_PCI_VFIO_H
+
+bool s390_pci_update_dma_avail(int fd, unsigned int *avail);
+
+#endif
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> --- hw/s390x/meson.build | 1 + hw/s390x/s390-pci-vfio.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++ hw/s390x/s390-pci-vfio.h | 17 +++++++++++++++ 3 files changed, 72 insertions(+) create mode 100644 hw/s390x/s390-pci-vfio.c create mode 100644 hw/s390x/s390-pci-vfio.h