hisi_acc_vfio_pci: add new vfio_pci driver for HiSilicon ACC devices

Add a vendor-specific vfio_pci driver for HiSilicon ACC devices.
This will be extended in subsequent patches to add support for VFIO
live migration feature.

Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20220308184902.2242-5-shameerali.kolothum.thodi@huawei.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

MAINTAINERS

@@ -20305,6 +20305,13 @@ L:	kvm@vger.kernel.org
 S:	Maintained
 F:	drivers/vfio/fsl-mc/
 
+VFIO HISILICON PCI DRIVER
+M:	Longfang Liu <liulongfang@huawei.com>
+M:	Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
+L:	kvm@vger.kernel.org
+S:	Maintained
+F:	drivers/vfio/pci/hisilicon/
+
 VFIO MEDIATED DEVICE DRIVERS
 M:	Kirti Wankhede <kwankhede@nvidia.com>
 L:	kvm@vger.kernel.org

drivers/vfio/pci/Kconfig

@@ -46,4 +46,6 @@ endif
 
 source "drivers/vfio/pci/mlx5/Kconfig"
 
+source "drivers/vfio/pci/hisilicon/Kconfig"
+
 endif

drivers/vfio/pci/Makefile

@@ -9,3 +9,5 @@ vfio-pci-$(CONFIG_VFIO_PCI_IGD) += vfio_pci_igd.o
 obj-$(CONFIG_VFIO_PCI) += vfio-pci.o
 
 obj-$(CONFIG_MLX5_VFIO_PCI)           += mlx5/
+
+obj-$(CONFIG_HISI_ACC_VFIO_PCI) += hisilicon/

drivers/vfio/pci/hisilicon/Kconfig

@@ -0,0 +1,10 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config HISI_ACC_VFIO_PCI
+	tristate "VFIO PCI support for HiSilicon ACC devices"
+	depends on ARM64 || (COMPILE_TEST && 64BIT)
+	depends on VFIO_PCI_CORE
+	help
+	  This provides generic PCI support for HiSilicon ACC devices
+	  using the VFIO framework.
+
+	  If you don't know what to do here, say N.

drivers/vfio/pci/hisilicon/Makefile

@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_HISI_ACC_VFIO_PCI) += hisi-acc-vfio-pci.o
+hisi-acc-vfio-pci-y := hisi_acc_vfio_pci.o
+

drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c

@@ -0,0 +1,100 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2021, HiSilicon Ltd.
+ */
+
+#include <linux/device.h>
+#include <linux/eventfd.h>
+#include <linux/file.h>
+#include <linux/hisi_acc_qm.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/vfio.h>
+#include <linux/vfio_pci_core.h>
+
+static int hisi_acc_vfio_pci_open_device(struct vfio_device *core_vdev)
+{
+	struct vfio_pci_core_device *vdev =
+		container_of(core_vdev, struct vfio_pci_core_device, vdev);
+	int ret;
+
+	ret = vfio_pci_core_enable(vdev);
+	if (ret)
+		return ret;
+
+	vfio_pci_core_finish_enable(vdev);
+
+	return 0;
+}
+
+static const struct vfio_device_ops hisi_acc_vfio_pci_ops = {
+	.name = "hisi-acc-vfio-pci",
+	.open_device = hisi_acc_vfio_pci_open_device,
+	.close_device = vfio_pci_core_close_device,
+	.ioctl = vfio_pci_core_ioctl,
+	.device_feature = vfio_pci_core_ioctl_feature,
+	.read = vfio_pci_core_read,
+	.write = vfio_pci_core_write,
+	.mmap = vfio_pci_core_mmap,
+	.request = vfio_pci_core_request,
+	.match = vfio_pci_core_match,
+};
+
+static int hisi_acc_vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
+{
+	struct vfio_pci_core_device *vdev;
+	int ret;
+
+	vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
+	if (!vdev)
+		return -ENOMEM;
+
+	vfio_pci_core_init_device(vdev, pdev, &hisi_acc_vfio_pci_ops);
+
+	ret = vfio_pci_core_register_device(vdev);
+	if (ret)
+		goto out_free;
+
+	dev_set_drvdata(&pdev->dev, vdev);
+
+	return 0;
+
+out_free:
+	vfio_pci_core_uninit_device(vdev);
+	kfree(vdev);
+	return ret;
+}
+
+static void hisi_acc_vfio_pci_remove(struct pci_dev *pdev)
+{
+	struct vfio_pci_core_device *vdev = dev_get_drvdata(&pdev->dev);
+
+	vfio_pci_core_unregister_device(vdev);
+	vfio_pci_core_uninit_device(vdev);
+	kfree(vdev);
+}
+
+static const struct pci_device_id hisi_acc_vfio_pci_table[] = {
+	{ PCI_DRIVER_OVERRIDE_DEVICE_VFIO(PCI_VENDOR_ID_HUAWEI, PCI_DEVICE_ID_HUAWEI_SEC_VF) },
+	{ PCI_DRIVER_OVERRIDE_DEVICE_VFIO(PCI_VENDOR_ID_HUAWEI, PCI_DEVICE_ID_HUAWEI_HPRE_VF) },
+	{ PCI_DRIVER_OVERRIDE_DEVICE_VFIO(PCI_VENDOR_ID_HUAWEI, PCI_DEVICE_ID_HUAWEI_ZIP_VF) },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(pci, hisi_acc_vfio_pci_table);
+
+static struct pci_driver hisi_acc_vfio_pci_driver = {
+	.name = KBUILD_MODNAME,
+	.id_table = hisi_acc_vfio_pci_table,
+	.probe = hisi_acc_vfio_pci_probe,
+	.remove = hisi_acc_vfio_pci_remove,
+	.err_handler = &vfio_pci_core_err_handlers,
+};
+
+module_pci_driver(hisi_acc_vfio_pci_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Liu Longfang <liulongfang@huawei.com>");
+MODULE_AUTHOR("Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>");
+MODULE_DESCRIPTION("HiSilicon VFIO PCI - Generic VFIO PCI driver for HiSilicon ACC device family");