Test and enable PCIe AtomicOp completer support of various widths and
report via device-info capability to userspace.
Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
---
drivers/vfio/pci/vfio_pci_core.c | 38 ++++++++++++++++++++++++++++++++
include/uapi/linux/vfio.h | 14 ++++++++++++
2 files changed, 52 insertions(+)
diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
index a5ab416cf476..a21ab726c9d4 100644
--- a/drivers/vfio/pci/vfio_pci_core.c
+++ b/drivers/vfio/pci/vfio_pci_core.c
@@ -882,6 +882,37 @@ int vfio_pci_core_register_dev_region(struct vfio_pci_core_device *vdev,
}
EXPORT_SYMBOL_GPL(vfio_pci_core_register_dev_region);
+static int vfio_pci_info_atomic_cap(struct vfio_pci_core_device *vdev,
+ struct vfio_info_cap *caps)
+{
+ struct vfio_device_info_cap_pci_atomic_comp cap = {
+ .header.id = VFIO_DEVICE_INFO_CAP_PCI_ATOMIC_COMP,
+ .header.version = 1
+ };
+ struct pci_dev *pdev = pci_physfn(vdev->pdev);
+ u32 devcap2;
+
+ pcie_capability_read_dword(pdev, PCI_EXP_DEVCAP2, &devcap2);
+
+ if ((devcap2 & PCI_EXP_DEVCAP2_ATOMIC_COMP32) &&
+ !pci_enable_atomic_ops_to_root(pdev, PCI_EXP_DEVCAP2_ATOMIC_COMP32))
+ cap.flags |= VFIO_PCI_ATOMIC_COMP32;
+
+ if ((devcap2 & PCI_EXP_DEVCAP2_ATOMIC_COMP64) &&
+ !pci_enable_atomic_ops_to_root(pdev, PCI_EXP_DEVCAP2_ATOMIC_COMP64))
+ cap.flags |= VFIO_PCI_ATOMIC_COMP64;
+
+ if ((devcap2 & PCI_EXP_DEVCAP2_ATOMIC_COMP128) &&
+ !pci_enable_atomic_ops_to_root(pdev,
+ PCI_EXP_DEVCAP2_ATOMIC_COMP128))
+ cap.flags |= VFIO_PCI_ATOMIC_COMP128;
+
+ if (!cap.flags)
+ return -ENODEV;
+
+ return vfio_info_add_capability(caps, &cap.header, sizeof(cap));
+}
+
static int vfio_pci_ioctl_get_info(struct vfio_pci_core_device *vdev,
struct vfio_device_info __user *arg)
{
@@ -920,6 +951,13 @@ static int vfio_pci_ioctl_get_info(struct vfio_pci_core_device *vdev,
return ret;
}
+ ret = vfio_pci_info_atomic_cap(vdev, &caps);
+ if (ret && ret != -ENODEV) {
+ pci_warn(vdev->pdev,
+ "Failed to setup AtomicOps info capability\n");
+ return ret;
+ }
+
if (caps.size) {
info.flags |= VFIO_DEVICE_FLAGS_CAPS;
if (info.argsz < sizeof(info) + caps.size) {
diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index 0552e8dcf0cb..07988d62b33c 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -240,6 +240,20 @@ struct vfio_device_info {
#define VFIO_DEVICE_INFO_CAP_ZPCI_UTIL 3
#define VFIO_DEVICE_INFO_CAP_ZPCI_PFIP 4
+/*
+ * The following VFIO_DEVICE_INFO capability reports support for PCIe AtomicOp
+ * completion to the root bus with supported widths provided via flags.
+ */
+#define VFIO_DEVICE_INFO_CAP_PCI_ATOMIC_COMP 5
+struct vfio_device_info_cap_pci_atomic_comp {
+ struct vfio_info_cap_header header;
+ __u32 flags;
+#define VFIO_PCI_ATOMIC_COMP32 (1 << 0)
+#define VFIO_PCI_ATOMIC_COMP64 (1 << 1)
+#define VFIO_PCI_ATOMIC_COMP128 (1 << 2)
+ __u32 reserved;
+};
+
/**
* VFIO_DEVICE_GET_REGION_INFO - _IOWR(VFIO_TYPE, VFIO_BASE + 8,
* struct vfio_region_info)
--
2.39.2
