[PATCH v4 4/4] vfio: pci: Using a device region to retrieve zPCI information

Matthew Rosato
2019-09-07T00:14:20Z

From: Pierre Morel <pmorel@linux.ibm.com>

We define a new configuration entry for VFIO/PCI, VFIO_PCI_ZDEV

When the VFIO_PCI_ZDEV feature is configured we initialize
a new device region, VFIO_REGION_SUBTYPE_ZDEV_CLP, to hold
the information from the ZPCI device the use

Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
---
drivers/vfio/pci/Kconfig | 7 +++
drivers/vfio/pci/Makefile | 1 +
drivers/vfio/pci/vfio_pci.c | 9 ++++
drivers/vfio/pci/vfio_pci_private.h | 10 +++++
drivers/vfio/pci/vfio_pci_zdev.c | 85 +++++++++++++++++++++++++++++++++++++
5 files changed, 112 insertions(+)
create mode 100644 drivers/vfio/pci/vfio_pci_zdev.c

diff --git a/drivers/vfio/pci/Kconfig b/drivers/vfio/pci/Kconfig
index ac3c1dd..d4562a8 100644
--- a/drivers/vfio/pci/Kconfig
+++ b/drivers/vfio/pci/Kconfig
@@ -45,3 +45,10 @@ config VFIO_PCI_NVLINK2
depends on VFIO_PCI && PPC_POWERNV
help
VFIO PCI support for P9 Witherspoon machine with NVIDIA V100 GPUs
+
+config VFIO_PCI_ZDEV
+ bool "VFIO PCI Generic for ZPCI devices"
+ depends on VFIO_PCI && S390
+ default y
+ help
+ VFIO PCI support for S390 Z-PCI devices
diff --git a/drivers/vfio/pci/Makefile b/drivers/vfio/pci/Makefile
index f027f8a..781e080 100644
--- a/drivers/vfio/pci/Makefile
+++ b/drivers/vfio/pci/Makefile
@@ -3,5 +3,6 @@
vfio-pci-y := vfio_pci.o vfio_pci_intrs.o vfio_pci_rdwr.o vfio_pci_config.o
vfio-pci-$(CONFIG_VFIO_PCI_IGD) += vfio_pci_igd.o
vfio-pci-$(CONFIG_VFIO_PCI_NVLINK2) += vfio_pci_nvlink2.o
+vfio-pci-$(CONFIG_VFIO_PCI_ZDEV) += vfio_pci_zdev.o

obj-$(CONFIG_VFIO_PCI) += vfio-pci.o
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index 703948c..b40544a 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -356,6 +356,15 @@ static int vfio_pci_enable(struct vfio_pci_device *vdev)
}
}

+ if (IS_ENABLED(CONFIG_VFIO_PCI_ZDEV)) {
+ ret = vfio_pci_zdev_init(vdev);
+ if (ret) {
+ dev_warn(&vdev->pdev->dev,
+ "Failed to setup ZDEV regions\n");
+ goto disable_exit;
+ }
+ }
+
vfio_pci_probe_mmaps(vdev);

return 0;
diff --git a/drivers/vfio/pci/vfio_pci_private.h b/drivers/vfio/pci/vfio_pci_private.h
index ee6ee91..08e02f5 100644
--- a/drivers/vfio/pci/vfio_pci_private.h
+++ b/drivers/vfio/pci/vfio_pci_private.h
@@ -186,4 +186,14 @@ static inline int vfio_pci_ibm_npu2_init(struct vfio_pci_device *vdev)
return -ENODEV;
}
#endif
+
+#ifdef CONFIG_VFIO_PCI_ZDEV
+extern int vfio_pci_zdev_init(struct vfio_pci_device *vdev);
+#else
+static inline int vfio_pci_zdev_init(struct vfio_pci_device *vdev)
+{
+ return -ENODEV;
+}
+#endif
+
#endif /* VFIO_PCI_PRIVATE_H */
diff --git a/drivers/vfio/pci/vfio_pci_zdev.c b/drivers/vfio/pci/vfio_pci_zdev.c
new file mode 100644
index 0000000..22e2b60
--- /dev/null
+++ b/drivers/vfio/pci/vfio_pci_zdev.c
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * VFIO ZPCI devices support
+ *
+ * Copyright (C) IBM Corp. 2019. All rights reserved.
+ * Author: Pierre Morel <pmorel@linux.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+#include <linux/io.h>
+#include <linux/pci.h>
+#include <linux/uaccess.h>
+#include <linux/vfio.h>
+#include <linux/vfio_zdev.h>
+
+#include "vfio_pci_private.h"
+
+static size_t vfio_pci_zdev_rw(struct vfio_pci_device *vdev,
+ char __user *buf, size_t count, loff_t *ppos,
+ bool iswrite)
+{
+ struct vfio_region_zpci_info *region;
+ struct zpci_dev *zdev;
+ unsigned int index = VFIO_PCI_OFFSET_TO_INDEX(*ppos);
+ loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK;
+
+ if (!vdev->pdev->bus)
+ return -ENODEV;
+
+ zdev = vdev->pdev->bus->sysdata;
+ if (!zdev)
+ return -ENODEV;
+
+ if (pos >= sizeof(*region) || iswrite)
+ return -EINVAL;
+
+ region = vdev->region[index - VFIO_PCI_NUM_REGIONS].data;
+ region->dasm = zdev->dma_mask;
+ region->start_dma = zdev->start_dma;
+ region->end_dma = zdev->end_dma;
+ region->msi_addr = zdev->msi_addr;
+ region->flags = VFIO_PCI_ZDEV_FLAGS_REFRESH;
+ region->gid = zdev->pfgid;
+ region->mui = zdev->fmb_update;
+ region->noi = zdev->max_msi;
+ memcpy(region->util_str, zdev->util_str, CLP_UTIL_STR_LEN);
+
+ count = min(count, (size_t)(sizeof(*region) - pos));
+ if (copy_to_user(buf, region, count))
+ return -EFAULT;
+
+ return count;
+}
+
+static void vfio_pci_zdev_release(struct vfio_pci_device *vdev,
+ struct vfio_pci_region *region)
+{
+ kfree(region->data);
+}
+
+static const struct vfio_pci_regops vfio_pci_zdev_regops = {
+ .rw = vfio_pci_zdev_rw,
+ .release = vfio_pci_zdev_release,
+};
+
+int vfio_pci_zdev_init(struct vfio_pci_device *vdev)
+{
+ struct vfio_region_zpci_info *region;
+ int ret;
+
+ region = kmalloc(sizeof(*region) + CLP_UTIL_STR_LEN, GFP_KERNEL);
+ if (!region)
+ return -ENOMEM;
+
+ ret = vfio_pci_register_dev_region(vdev,
+ PCI_VENDOR_ID_IBM | VFIO_REGION_TYPE_PCI_VENDOR_TYPE,
+ VFIO_REGION_SUBTYPE_ZDEV_CLP,
+ &vfio_pci_zdev_regops, sizeof(*region) + CLP_UTIL_STR_LEN,
+ VFIO_REGION_INFO_FLAG_READ, region);
+
+ return ret;
+}
--
1.8.3.1