Commit a5bfe22d authored by Alex Williamson's avatar Alex Williamson
Browse files

vfio/pci-core: Add capability for AtomicOp completer support 



Test and enable PCIe AtomicOp completer support of various widths and
report via device-info capability to userspace.

Reviewed-by: default avatarCédric Le Goater <clg@redhat.com>
Reviewed-by: default avatarRobin Voetter <robin@streamhpc.com>
Tested-by: default avatarRobin Voetter <robin@streamhpc.com>
Link: https://lore.kernel.org/r/20230519214748.402003-1-alex.williamson@redhat.com


Signed-off-by: default avatarAlex Williamson <alex.williamson@redhat.com>
parent d9824f70

drivers/vfio/pci/vfio_pci_core.c

+38 −0
Original line number Diff line number Diff line
@@ -885,6 +885,37 @@ 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)

{
@@ -923,6 +954,13 @@ 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) {

include/uapi/linux/vfio.h

+14 −0
Original line number Diff line number Diff line
@@ -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)