File 0154-s390x-pci-Add-routine-to-get-the-vf.patch of Package qemu.20748
From: Matthew Rosato <mjrosato@linux.ibm.com>
Date: Mon, 26 Oct 2020 11:34:34 -0400
Subject: s390x/pci: Add routine to get the vfio dma available count
Include-If: %if 0%{?suse_version} == 1315
Git-commit: cd7498d07fbb20fa04790ff7ee168a8a8d01cb30
References: bsc#1179725
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>
Signed-off-by: Cho, Yu-Chen <acho@suse.com>
---
hw/s390x/Makefile.objs | 1 +
hw/s390x/s390-pci-vfio.c | 53 ++++++++++++++++++++++++++++++++
include/hw/s390x/s390-pci-vfio.h | 24 +++++++++++++++
3 files changed, 78 insertions(+)
diff --git a/hw/s390x/Makefile.objs b/hw/s390x/Makefile.objs
index ca68806e4418b31c680e6bc91a3c..3d5bdb72d9cd16953b0fe301987e 100644
--- a/hw/s390x/Makefile.objs
+++ b/hw/s390x/Makefile.objs
@@ -8,6 +8,7 @@ obj-y += css.o
obj-y += s390-virtio-ccw.o
obj-y += 3270-ccw.o
obj-y += virtio-ccw.o
+obj-$(CONFIG_LINUX) += s390-pci-vfio.o
obj-$(CONFIG_VIRTIO_SERIAL) += virtio-ccw-serial.o
obj-$(CONFIG_VIRTIO_BALLOON) += virtio-ccw-balloon.o
obj-$(CONFIG_VIRTIO_SCSI) += virtio-ccw-scsi.o
diff --git a/hw/s390x/s390-pci-vfio.c b/hw/s390x/s390-pci-vfio.c
new file mode 100644
index 0000000000000000000000000000000000000000..0f2eae062f93cd2c1f5fda59c64a2148a940894c
--- /dev/null
+++ b/hw/s390x/s390-pci-vfio.c
@@ -0,0 +1,53 @@
+/*
+ * 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);
+}
diff --git a/include/hw/s390x/s390-pci-vfio.h b/include/hw/s390x/s390-pci-vfio.h
new file mode 100644
index 0000000000000000000000000000000000000000..1727292e9b5d019ac2218a54eac244640a06d2ae
--- /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 <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
+
+#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
