On 9/22/20 7:22 AM, Cornelia Huck wrote:
On Sat, 19 Sep 2020 11:28:38 -0400
Matthew Rosato <mjrosato@xxxxxxxxxxxxx> wrote:
Define a new configuration entry VFIO_PCI_ZDEV for VFIO/PCI.
When this s390-only feature is configured we initialize a new device
region, VFIO_REGION_SUBTYPE_IBM_ZPCI_CLP, to hold information provided
by the 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 | 8 ++
drivers/vfio/pci/vfio_pci_private.h | 10 ++
drivers/vfio/pci/vfio_pci_zdev.c | 242 ++++++++++++++++++++++++++++++++++++
Maybe you want to add yourself to MAINTAINERS for the zdev-specific
files? You're probably better suited to review changes to the
zpci-specific code :)
Of course, will do. Looking at how we split vfio-ap and vfio-ccw, I'll
add an S390 VFIO-PCI DRIVER category and point to the new .h and .c file
for now.
5 files changed, 274 insertions(+)
create mode 100644 drivers/vfio/pci/vfio_pci_zdev.c
(...)
+int vfio_pci_zdev_init(struct vfio_pci_device *vdev)
+{
+ struct vfio_region_zpci_info *region;
+ struct zpci_dev *zdev;
+ size_t clp_offset;
+ int size;
+ int ret;
+
+ if (!vdev->pdev->bus)
+ return -ENODEV;
+
+ zdev = to_zpci(vdev->pdev);
+ if (!zdev)
+ return -ENODEV;
+
+ /* Calculate size needed for all supported CLP features */
+ size = sizeof(*region) +
+ sizeof(struct vfio_region_zpci_info_qpci) +
+ sizeof(struct vfio_region_zpci_info_qpcifg) +
+ (sizeof(struct vfio_region_zpci_info_util) + CLP_UTIL_STR_LEN) +
+ (sizeof(struct vfio_region_zpci_info_pfip) +
+ CLP_PFIP_NR_SEGMENTS);
+
+ region = kmalloc(size, GFP_KERNEL);
+ if (!region)
+ return -ENOMEM;
+
+ /* Fill in header */
+ region->argsz = size;
+ clp_offset = region->offset = sizeof(struct vfio_region_zpci_info);
+
+ /* Fill the supported CLP features */
+ clp_offset = vfio_pci_zdev_add_qpci(zdev, region, clp_offset);
+ clp_offset = vfio_pci_zdev_add_qpcifg(zdev, region, clp_offset);
+ clp_offset = vfio_pci_zdev_add_util(zdev, region, clp_offset);
+ clp_offset = vfio_pci_zdev_add_pfip(zdev, region, clp_offset);
So, the regions are populated once. Can any of the values in the
hardware structures be modified by a guest? Or changed from the
hardware side?
The region is created read-only (vfio_pci_zdev_rw returns -EINVAL on
writes), so no guest modification. The expectation is the guest can
read the region and take what it wants / ignore what it doesn't.
The CLPs covered by this region are not intended to change once the
device is up.
If we end up needing either of the above for a different CLP, I would
think an additional/different region would be appropriate.
+
+ ret = vfio_pci_register_dev_region(vdev,
+ PCI_VENDOR_ID_IBM | VFIO_REGION_TYPE_PCI_VENDOR_TYPE,
+ VFIO_REGION_SUBTYPE_IBM_ZPCI_CLP, &vfio_pci_zdev_regops,
+ size, VFIO_REGION_INFO_FLAG_READ, region);
+ if (ret)
+ kfree(region);
+
+ return ret;
+}
