RE: [RFC v2 1/4] hisi-acc-vfio-pci: add new vfio_pci driver for HiSilicon ACC devices

-----Original Message-----
From: Alex Williamson [mailto:alex.williamson@redhat.com]
Sent: 02 July 2021 21:29
To: Shameerali Kolothum Thodi <redacted>
Cc: kvm@vger.kernel.org; linux-kernel@vger.kernel.org;
linux-crypto@vger.kernel.org; jgg@nvidia.com; mgurtovoy@nvidia.com;
Linuxarm [off-list ref]; liulongfang [off-list ref];
Zengtao (B) [off-list ref]; yuzenghui
[off-list ref]; Jonathan Cameron
[off-list ref]; Wangzhou (B) [off-list ref]
Subject: Re: [RFC v2 1/4] hisi-acc-vfio-pci: add new vfio_pci driver for HiSilicon
ACC devices

On Fri, 2 Jul 2021 10:58:46 +0100
Shameer Kolothum [off-list ref] wrote:

quoted

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

Signed-off-by: Shameer Kolothum

[off-list ref]

quoted

---
 drivers/vfio/pci/Kconfig             |   9 +++
 drivers/vfio/pci/Makefile            |   2 +
 drivers/vfio/pci/hisi_acc_vfio_pci.c | 100 +++++++++++++++++++++++++++
 3 files changed, 111 insertions(+)
 create mode 100644 drivers/vfio/pci/hisi_acc_vfio_pci.c

diff --git a/drivers/vfio/pci/Kconfig b/drivers/vfio/pci/Kconfig
index 9cdef46dd299..709807c28153 100644
--- a/drivers/vfio/pci/Kconfig
+++ b/drivers/vfio/pci/Kconfig

@@ -57,3 +57,12 @@ config MLX5_VFIO_PCI
 	  framework.

 	  If you don't know what to do here, say N.
+
+config HISI_ACC_VFIO_PCI
+	tristate "VFIO support for HiSilicon ACC devices"
+	depends on ARM64 && VFIO_PCI_CORE
+	help
+	  This provides generic PCI support for HiSilicon devices using the VFIO
+	  framework.
+
+	  If you don't know what to do here, say N.

diff --git a/drivers/vfio/pci/Makefile b/drivers/vfio/pci/Makefile
index a0df9c2a4bd9..d1de3e81921f 100644
--- a/drivers/vfio/pci/Makefile
+++ b/drivers/vfio/pci/Makefile

@@ -3,6 +3,7 @@
 obj-$(CONFIG_VFIO_PCI_CORE) += vfio-pci-core.o
 obj-$(CONFIG_VFIO_PCI) += vfio-pci.o
 obj-$(CONFIG_MLX5_VFIO_PCI) += mlx5-vfio-pci.o
+obj-$(CONFIG_HISI_ACC_VFIO_PCI) += hisi-acc-vfio-pci.o

 vfio-pci-core-y := vfio_pci_core.o vfio_pci_intrs.o vfio_pci_rdwr.o

vfio_pci_config.o

quoted

 vfio-pci-core-$(CONFIG_S390) += vfio_pci_zdev.o

@@ -11,3 +12,4 @@ vfio-pci-y := vfio_pci.o
 vfio-pci-$(CONFIG_VFIO_PCI_IGD) += vfio_pci_igd.o

 mlx5-vfio-pci-y := mlx5_vfio_pci.o
+hisi-acc-vfio-pci-y := hisi_acc_vfio_pci.o

diff --git a/drivers/vfio/pci/hisi_acc_vfio_pci.c

b/drivers/vfio/pci/hisi_acc_vfio_pci.c

quoted

new file mode 100644
index 000000000000..a9e173098ab5

--- /dev/null
+++ b/drivers/vfio/pci/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/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(struct vfio_device *core_vdev)
+{
+	struct vfio_pci_core_device *vdev =
+		container_of(core_vdev, struct vfio_pci_core_device, vdev);
+	int ret;
+
+	lockdep_assert_held(&core_vdev->reflck->lock);
+
+	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		= hisi_acc_vfio_pci_open,
+	.release	= vfio_pci_core_release,
+	.ioctl		= vfio_pci_core_ioctl,
+	.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,
+	.reflck_attach	= vfio_pci_core_reflck_attach,
+};
+
+static int hisi_acc_vfio_pci_probe(struct pci_dev *pdev, const struct

pci_device_id *id)

quoted

+{
+	struct vfio_pci_core_device *vdev;
+	int ret;
+
+	vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
+	if (!vdev)
+		return -ENOMEM;
+
+	ret = vfio_pci_core_register_device(vdev, pdev, &hisi_acc_vfio_pci_ops);
+	if (ret)
+		goto out_free;
+
+	dev_set_drvdata(&pdev->dev, vdev);
+
+	return 0;
+
+out_free:
+	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);
+	kfree(vdev);
+}
+
+static const struct pci_device_id hisi_acc_vfio_pci_table[] = {
+	{ PCI_DRIVER_OVERRIDE_DEVICE_VFIO(PCI_VENDOR_ID_HUAWEI,

0xa256) }, /* SEC VF */

quoted

+	{ PCI_DRIVER_OVERRIDE_DEVICE_VFIO(PCI_VENDOR_ID_HUAWEI,

0xa259) }, /* HPRE VF */

quoted

+	{ PCI_DRIVER_OVERRIDE_DEVICE_VFIO(PCI_VENDOR_ID_HUAWEI,

0xa251) }, /* ZIP VF */

quoted

+	{ 0, }
+};
+
+MODULE_DEVICE_TABLE(pci, hisi_acc_vfio_pci_table);
+
+static struct pci_driver hisi_acc_vfio_pci_driver = {
+	.name			= "hisi-acc-vfio-pci",
+	.id_table		= hisi_acc_vfio_pci_table,
+	.probe			= hisi_acc_vfio_pci_probe,
+	.remove			= hisi_acc_vfio_pci_remove,
+#ifdef CONFIG_PCI_IOV
+	.sriov_configure	= vfio_pci_core_sriov_configure,
+#endif

The device table suggests only VFs are supported by this driver, so it
really shouldn't need sriov_configure support, right?  Thanks,

Right. Only VFs are supported. I will remove this.

Thanks,
Shameer

Alex

quoted

+	.err_handler		= &vfio_pci_core_err_handlers,
+};
+
+module_pci_driver(hisi_acc_vfio_pci_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Liu Longfang [off-list ref]");
+MODULE_AUTHOR("Shameer Kolothum

[off-list ref]");

quoted

+MODULE_DESCRIPTION("HiSilicon VFIO PCI - Generic VFIO PCI driver for

HiSilicon ACC device family");