[PATCH v3 4/5] vfio-pci/zdev: Add zPCI capabilities to VFIO_DEVICE_GET_INFO
From: Matthew Rosato
Date: Wed Oct 07 2020 - 14:56:56 EST
Define a new configuration entry VFIO_PCI_ZDEV for VFIO/PCI.
When this s390-only feature is configured we add capabilities to the
VFIO_DEVICE_GET_INFO ioctl that describe features of the associated
zPCI device and its underlying hardware.
This patch is based on work previously done by Pierre Morel.
Signed-off-by: Matthew Rosato <mjrosato@xxxxxxxxxxxxx>
---
drivers/vfio/pci/Kconfig | 13 ++++
drivers/vfio/pci/Makefile | 1 +
drivers/vfio/pci/vfio_pci.c | 37 ++++++++++
drivers/vfio/pci/vfio_pci_private.h | 12 +++
drivers/vfio/pci/vfio_pci_zdev.c | 143 ++++++++++++++++++++++++++++++++++++
5 files changed, 206 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..6adf37a 100644
--- a/drivers/vfio/pci/Kconfig
+++ b/drivers/vfio/pci/Kconfig
@@ -45,3 +45,16 @@ 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 ZPCI device CLP support"
+ depends on VFIO_PCI && S390
+ default y
+ help
+ Enabling this option exposes VFIO capabilities containing hardware
+ configuration for zPCI devices. This enables userspace (e.g. QEMU)
+ to supply proper configuration values instead of hard-coded defaults
+ for zPCI devices passed through via VFIO on s390.
+
+ Say Y here.
+
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 1ab1f5c..208dea5 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -807,15 +807,25 @@ static long vfio_pci_ioctl(void *device_data,
if (cmd == VFIO_DEVICE_GET_INFO) {
struct vfio_device_info info;
+ struct vfio_info_cap caps = { .buf = NULL, .size = 0 };
+ unsigned long capsz;
minsz = offsetofend(struct vfio_device_info, num_irqs);
+ /* For backward compatibility, cannot require this */
+ capsz = offsetofend(struct vfio_iommu_type1_info, cap_offset);
+
if (copy_from_user(&info, (void __user *)arg, minsz))
return -EFAULT;
if (info.argsz < minsz)
return -EINVAL;
+ if (info.argsz >= capsz) {
+ minsz = capsz;
+ info.cap_offset = 0;
+ }
+
info.flags = VFIO_DEVICE_FLAGS_PCI;
if (vdev->reset_works)
@@ -824,6 +834,33 @@ static long vfio_pci_ioctl(void *device_data,
info.num_regions = VFIO_PCI_NUM_REGIONS + vdev->num_regions;
info.num_irqs = VFIO_PCI_NUM_IRQS;
+ if (IS_ENABLED(CONFIG_VFIO_PCI_ZDEV)) {
+ int ret = vfio_pci_info_zdev_add_caps(vdev, &caps);
+
+ if (ret && ret != -ENODEV) {
+ pci_warn(vdev->pdev, "Failed to setup zPCI info capabilities\n");
+ return ret;
+ }
+ }
+
+ if (caps.size) {
+ info.flags |= VFIO_DEVICE_FLAGS_CAPS;
+ if (info.argsz < sizeof(info) + caps.size) {
+ info.argsz = sizeof(info) + caps.size;
+ } else {
+ vfio_info_cap_shift(&caps, sizeof(info));
+ if (copy_to_user((void __user *)arg +
+ sizeof(info), caps.buf,
+ caps.size)) {
+ kfree(caps.buf);
+ return -EFAULT;
+ }
+ info.cap_offset = sizeof(info);
+ }
+
+ kfree(caps.buf);
+ }
+
return copy_to_user((void __user *)arg, &info, minsz) ?
-EFAULT : 0;
diff --git a/drivers/vfio/pci/vfio_pci_private.h b/drivers/vfio/pci/vfio_pci_private.h
index 61ca8ab..9d28484 100644
--- a/drivers/vfio/pci/vfio_pci_private.h
+++ b/drivers/vfio/pci/vfio_pci_private.h
@@ -213,4 +213,16 @@ 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_info_zdev_add_caps(struct vfio_pci_device *vdev,
+ struct vfio_info_cap *caps);
+#else
+static inline int vfio_pci_info_zdev_add_caps(struct vfio_pci_device *vdev,
+ struct vfio_info_cap *caps);
+{
+ 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..2296856
--- /dev/null
+++ b/drivers/vfio/pci/vfio_pci_zdev.c
@@ -0,0 +1,143 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * VFIO ZPCI devices support
+ *
+ * Copyright (C) IBM Corp. 2020. All rights reserved.
+ * Author(s): Pierre Morel <pmorel@xxxxxxxxxxxxx>
+ * Matthew Rosato <mjrosato@xxxxxxxxxxxxx>
+ *
+ * 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 <asm/pci_clp.h>
+#include <asm/pci_io.h>
+
+#include "vfio_pci_private.h"
+
+/*
+ * Add the Base PCI Function information to the device info region.
+ */
+static int zpci_base_cap(struct zpci_dev *zdev, struct vfio_pci_device *vdev,
+ struct vfio_info_cap *caps)
+{
+ struct vfio_device_info_cap_zpci_base cap = {
+ .header.id = VFIO_DEVICE_INFO_CAP_ZPCI_BASE,
+ .header.version = 1,
+ .start_dma = zdev->start_dma,
+ .end_dma = zdev->end_dma,
+ .pchid = zdev->pchid,
+ .vfn = zdev->vfn,
+ .fmb_length = zdev->fmb_length,
+ .pft = zdev->pft,
+ .gid = zdev->pfgid
+ };
+
+ return vfio_info_add_capability(caps, &cap.header, sizeof(cap));
+}
+
+/*
+ * Add the Base PCI Function Group information to the device info region.
+ */
+static int zpci_group_cap(struct zpci_dev *zdev, struct vfio_pci_device *vdev,
+ struct vfio_info_cap *caps)
+{
+ struct vfio_device_info_cap_zpci_group cap = {
+ .header.id = VFIO_DEVICE_INFO_CAP_ZPCI_GROUP,
+ .header.version = 1,
+ .dasm = zdev->dma_mask,
+ .msi_addr = zdev->msi_addr,
+ .flags = VFIO_DEVICE_INFO_ZPCI_FLAG_REFRESH,
+ .mui = zdev->fmb_update,
+ .noi = zdev->max_msi,
+ .maxstbl = ZPCI_MAX_WRITE_SIZE,
+ .version = zdev->version
+ };
+
+ return vfio_info_add_capability(caps, &cap.header, sizeof(cap));
+}
+
+/*
+ * Add the device utility string to the device info region.
+ */
+static int zpci_util_cap(struct zpci_dev *zdev, struct vfio_pci_device *vdev,
+ struct vfio_info_cap *caps)
+{
+ struct vfio_device_info_cap_zpci_util *cap;
+ int cap_size = sizeof(*cap) + CLP_UTIL_STR_LEN;
+ int ret;
+
+ cap = kmalloc(cap_size, GFP_KERNEL);
+
+ cap->header.id = VFIO_DEVICE_INFO_CAP_ZPCI_UTIL;
+ cap->header.version = 1;
+ cap->size = CLP_UTIL_STR_LEN;
+ memcpy(cap->util_str, zdev->util_str, cap->size);
+
+ ret = vfio_info_add_capability(caps, &cap->header, cap_size);
+
+ kfree(cap);
+
+ return ret;
+}
+
+/*
+ * Add the function path string to the device info region.
+ */
+static int zpci_pfip_cap(struct zpci_dev *zdev, struct vfio_pci_device *vdev,
+ struct vfio_info_cap *caps)
+{
+ struct vfio_device_info_cap_zpci_pfip *cap;
+ int cap_size = sizeof(*cap) + CLP_PFIP_NR_SEGMENTS;
+ int ret;
+
+ cap = kmalloc(cap_size, GFP_KERNEL);
+
+ cap->header.id = VFIO_DEVICE_INFO_CAP_ZPCI_PFIP;
+ cap->header.version = 1;
+ cap->size = CLP_PFIP_NR_SEGMENTS;
+ memcpy(cap->pfip, zdev->pfip, cap->size);
+
+ ret = vfio_info_add_capability(caps, &cap->header, cap_size);
+
+ kfree(cap);
+
+ return ret;
+}
+
+/*
+ * Add all supported capabilities to the VFIO_DEVICE_GET_INFO capability chain.
+ */
+int vfio_pci_info_zdev_add_caps(struct vfio_pci_device *vdev,
+ struct vfio_info_cap *caps)
+{
+ struct zpci_dev *zdev = to_zpci(vdev->pdev);
+ int ret;
+
+ if (!zdev)
+ return -ENODEV;
+
+ ret = zpci_base_cap(zdev, vdev, caps);
+ if (ret)
+ return ret;
+
+ ret = zpci_group_cap(zdev, vdev, caps);
+ if (ret)
+ return ret;
+
+ if (zdev->util_str_avail) {
+ ret = zpci_util_cap(zdev, vdev, caps);
+ if (ret)
+ return ret;
+ }
+
+ ret = zpci_pfip_cap(zdev, vdev, caps);
+
+ return ret;
+}
--
1.8.3.1