[Intel-wired-lan] [PATCH iwl-next V2 13/15] vfio/ice: implement vfio_pci driver for E800 devices

[Lingyu Liu <lingyu.liu@intel.com>]

Add a vendor-specific vfio_pci driver for E800 devices.

It uses vfio_pci_core to register to the VFIO subsystem and then
implements the E800 specific logic to support VF live migration.

It implements the device state transition flow for live
migration.

Signed-off-by: Lingyu Liu <lingyu.liu@intel.com>
Signed-off-by: Yahui Cao <yahui.cao@intel.com>
---
 MAINTAINERS                         |   7 +
 drivers/vfio/pci/Kconfig            |   2 +
 drivers/vfio/pci/Makefile           |   2 +
 drivers/vfio/pci/ice/Kconfig        |  10 +
 drivers/vfio/pci/ice/Makefile       |   4 +
 drivers/vfio/pci/ice/ice_vfio_pci.c | 841 ++++++++++++++++++++++++++++
 6 files changed, 866 insertions(+)
 create mode 100644 drivers/vfio/pci/ice/Kconfig
 create mode 100644 drivers/vfio/pci/ice/Makefile
 create mode 100644 drivers/vfio/pci/ice/ice_vfio_pci.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 7322963b0670..39a2d7c15dc4 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -22170,6 +22170,13 @@ L:	kvm@vger.kernel.org
 S:	Maintained
 F:	drivers/vfio/pci/mlx5/
 
+VFIO ICE PCI DRIVER
+M:	Yahui Cao <yahui.cao@intel.com>
+M:	Lingyu Liu <lingyu.liu@intel.com>
+L:	kvm@vger.kernel.org
+S:	Maintained
+F:	drivers/vfio/pci/ice/
+
 VFIO PCI DEVICE SPECIFIC DRIVERS
 R:	Jason Gunthorpe <jgg@nvidia.com>
 R:	Yishai Hadas <yishaih@nvidia.com>
diff --git a/drivers/vfio/pci/Kconfig b/drivers/vfio/pci/Kconfig
index f9d0c908e738..834ad57c7455 100644
--- a/drivers/vfio/pci/Kconfig
+++ b/drivers/vfio/pci/Kconfig
@@ -59,4 +59,6 @@ source "drivers/vfio/pci/mlx5/Kconfig"
 
 source "drivers/vfio/pci/hisilicon/Kconfig"
 
+source "drivers/vfio/pci/ice/Kconfig"
+
 endif
diff --git a/drivers/vfio/pci/Makefile b/drivers/vfio/pci/Makefile
index 24c524224da5..12d2ee3350c5 100644
--- a/drivers/vfio/pci/Makefile
+++ b/drivers/vfio/pci/Makefile
@@ -11,3 +11,5 @@ obj-$(CONFIG_VFIO_PCI) += vfio-pci.o
 obj-$(CONFIG_MLX5_VFIO_PCI)           += mlx5/
 
 obj-$(CONFIG_HISI_ACC_VFIO_PCI) += hisilicon/
+
+obj-$(CONFIG_ICE_VFIO_PCI) += ice/
diff --git a/drivers/vfio/pci/ice/Kconfig b/drivers/vfio/pci/ice/Kconfig
new file mode 100644
index 000000000000..4c6f348d3062
--- /dev/null
+++ b/drivers/vfio/pci/ice/Kconfig
@@ -0,0 +1,10 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config ICE_VFIO_PCI
+	tristate "VFIO support for Intel(R) Ethernet Connection E800 Series"
+	depends on ICE
+	depends on VFIO_PCI_CORE
+	help
+	  This provides migration support for Intel(R) Ethernet connection E800
+	  series devices using the VFIO framework.
+
+	  If you don't know what to do here, say N.
diff --git a/drivers/vfio/pci/ice/Makefile b/drivers/vfio/pci/ice/Makefile
new file mode 100644
index 000000000000..259d4ab89105
--- /dev/null
+++ b/drivers/vfio/pci/ice/Makefile
@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_ICE_VFIO_PCI) += ice-vfio-pci.o
+ice-vfio-pci-y := ice_vfio_pci.o
+
diff --git a/drivers/vfio/pci/ice/ice_vfio_pci.c b/drivers/vfio/pci/ice/ice_vfio_pci.c
new file mode 100644
index 000000000000..389a2be41896
--- /dev/null
+++ b/drivers/vfio/pci/ice/ice_vfio_pci.c
@@ -0,0 +1,841 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2018-2023 Intel Corporation */
+
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/file.h>
+
+#include <linux/net/intel/ice_migration.h>
+#include <linux/vfio_pci_core.h>
+#include <linux/anon_inodes.h>
+
+#define DRIVER_DESC     "ICE VFIO PCI - User Level meta-driver for Intel E800 device family"
+
+/* IAVF registers description */
+#define IAVF_VF_ARQBAH1 0x00006000 /* Reset: EMPR */
+#define IAVF_VF_ATQH1 0x00006400 /* Reset: EMPR */
+#define IAVF_VF_ATQLEN1 0x00006800 /* Reset: EMPR */
+#define IAVF_VF_ARQBAL1 0x00006C00 /* Reset: EMPR */
+#define IAVF_VF_ARQT1 0x00007000   /* Reset: EMPR */
+#define IAVF_VF_ARQH1 0x00007400   /* Reset: EMPR */
+#define IAVF_VF_ATQBAH1 0x00007800 /* Reset: EMPR */
+#define IAVF_VF_ATQBAL1 0x00007C00 /* Reset: EMPR */
+#define IAVF_VF_ARQLEN1 0x00008000 /* Reset: EMPR */
+#define IAVF_VF_ATQT1 0x00008400   /* Reset: EMPR */
+#define IAVF_VFINT_DYN_CTL01 0x00005C00 /* Reset: VFR */
+#define IAVF_VFINT_DYN_CTLN1(_INTVF) \
+	(0x00003800 + ((_INTVF) * 4)) /* _INTVF=0...16 */ /* Reset: VFR */
+#define IAVF_VFINT_DYN_CTLN_NUM 16
+#define IAVF_VFINT_ITRN0(_i) \
+	(0x00004C00 + (_i) * 4) /* _i=0...2 */ /* Reset: VFR */
+#define IAVF_VFINT_ITRN0_NUM 3
+#define IAVF_VFINT_ITRN1(_i, _INTVF) (0x00002800 + ((_i) * 64 + (_INTVF) * 4))
+	/* _i=0...2, _INTVF=0...15 */ /* Reset: VFR */
+#define IAVF_VFINT_ITRN_NUM 3
+#define IAVF_QRX_TAIL1(_Q) \
+	(0x00002000 + ((_Q) * 4)) /* _Q=0...256 */ /* Reset: CORER */
+
+/* Registers for saving and loading during live Migration */
+struct ice_vfio_pci_regs {
+	/* VF interrupts */
+	u32 int_dyn_ctl0;
+	u32 int_dyn_ctln[IAVF_VFINT_DYN_CTLN_NUM];
+	u32 int_intr0[IAVF_VFINT_ITRN0_NUM];
+	u32 int_intrn[IAVF_VFINT_ITRN_NUM][IAVF_VFINT_DYN_CTLN_NUM];
+
+	/* VF Control Queues */
+	u32 asq_bal;
+	u32 asq_bah;
+	u32 asq_len;
+	u32 asq_head;
+	u32 asq_tail;
+	u32 arq_bal;
+	u32 arq_bah;
+	u32 arq_len;
+	u32 arq_head;
+	u32 arq_tail;
+
+	/* VF LAN RX */
+	u32 rx_tail[IAVF_QRX_TAIL_MAX];
+};
+
+struct ice_vfio_pci_migration_data {
+	struct ice_vfio_pci_regs regs;
+
+	u8 __aligned(8) dev_state[SZ_128K];
+};
+
+struct ice_vfio_pci_migration_file {
+	struct file *filp;
+	struct mutex lock;
+	bool disabled;
+
+	struct ice_vfio_pci_migration_data mig_data;
+	size_t total_length;
+};
+
+struct ice_vfio_pci_core_device {
+	struct vfio_pci_core_device core_device;
+	u8 deferred_reset:1;
+	/* protect migration state */
+	struct mutex state_mutex;
+	enum vfio_device_mig_state mig_state;
+	/* protect the reset_done flow */
+	spinlock_t reset_lock;
+	struct ice_vfio_pci_migration_file *resuming_migf;
+	struct ice_vfio_pci_migration_file *saving_migf;
+	struct vfio_device_migration_info mig_info;
+	struct ice_vfio_pci_migration_data *mig_data;
+	u8 __iomem *io_base;
+	void *vf_handle;
+	bool is_dst;
+};
+
+/**
+ * ice_vfio_pci_save_regs - Save migration register data
+ * @ice_vdev: pointer to ice vfio pci core device structure
+ * @regs: pointer to ice_vfio_pci_regs structure
+ *
+ */
+static void
+ice_vfio_pci_save_regs(struct ice_vfio_pci_core_device *ice_vdev,
+		       struct ice_vfio_pci_regs *regs)
+{
+	u8 __iomem *io_base = ice_vdev->io_base;
+	int i, j;
+
+	regs->int_dyn_ctl0 = readl(io_base + IAVF_VFINT_DYN_CTL01);
+
+	for (i = 0; i < IAVF_VFINT_DYN_CTLN_NUM; i++)
+		regs->int_dyn_ctln[i] =
+		    readl(io_base + IAVF_VFINT_DYN_CTLN1(i));
+
+	for (i = 0; i < IAVF_VFINT_ITRN0_NUM; i++)
+		regs->int_intr0[i] = readl(io_base + IAVF_VFINT_ITRN0(i));
+
+	for (i = 0; i < IAVF_VFINT_ITRN_NUM; i++)
+		for (j = 0; j < IAVF_VFINT_DYN_CTLN_NUM; j++)
+			regs->int_intrn[i][j] =
+			    readl(io_base + IAVF_VFINT_ITRN1(i, j));
+
+	regs->asq_bal = readl(io_base + IAVF_VF_ATQBAL1);
+	regs->asq_bah = readl(io_base + IAVF_VF_ATQBAH1);
+	regs->asq_len = readl(io_base + IAVF_VF_ATQLEN1);
+	regs->asq_head = readl(io_base + IAVF_VF_ATQH1);
+	regs->asq_tail = readl(io_base + IAVF_VF_ATQT1);
+	regs->arq_bal = readl(io_base + IAVF_VF_ARQBAL1);
+	regs->arq_bah = readl(io_base + IAVF_VF_ARQBAH1);
+	regs->arq_len = readl(io_base +  IAVF_VF_ARQLEN1);
+	regs->arq_head = readl(io_base + IAVF_VF_ARQH1);
+	regs->arq_tail = readl(io_base + IAVF_VF_ARQT1);
+
+	for (i = 0; i < IAVF_QRX_TAIL_MAX; i++)
+		regs->rx_tail[i] = readl(io_base + IAVF_QRX_TAIL1(i));
+}
+
+/**
+ * ice_vfio_pci_load_regs - Load migration register data
+ * @ice_vdev: pointer to ice vfio pci core device structure
+ * @regs: pointer to ice_vfio_pci_regs structure
+ *
+ */
+static void
+ice_vfio_pci_load_regs(struct ice_vfio_pci_core_device *ice_vdev,
+		       struct ice_vfio_pci_regs *regs)
+{
+	u8 __iomem *io_base = ice_vdev->io_base;
+	int i, j;
+
+	writel(regs->int_dyn_ctl0, io_base + IAVF_VFINT_DYN_CTL01);
+
+	for (i = 0; i < IAVF_VFINT_DYN_CTLN_NUM; i++)
+		writel(regs->int_dyn_ctln[i],
+		       io_base + IAVF_VFINT_DYN_CTLN1(i));
+
+	for (i = 0; i < IAVF_VFINT_ITRN0_NUM; i++)
+		writel(regs->int_intr0[i], io_base + IAVF_VFINT_ITRN0(i));
+
+	for (i = 0; i < IAVF_VFINT_ITRN_NUM; i++)
+		for (j = 0; j < IAVF_VFINT_DYN_CTLN_NUM; j++)
+			writel(regs->int_intrn[i][j],
+			       io_base + IAVF_VFINT_ITRN1(i, j));
+
+	writel(regs->asq_bal, io_base + IAVF_VF_ATQBAL1);
+	writel(regs->asq_bah, io_base + IAVF_VF_ATQBAH1);
+	writel(regs->asq_len, io_base + IAVF_VF_ATQLEN1);
+	writel(regs->asq_head, io_base + IAVF_VF_ATQH1);
+	writel(regs->asq_tail, io_base + IAVF_VF_ATQT1);
+	writel(regs->arq_bal, io_base + IAVF_VF_ARQBAL1);
+	writel(regs->arq_bah, io_base + IAVF_VF_ARQBAH1);
+	writel(regs->arq_len, io_base +  IAVF_VF_ARQLEN1);
+	writel(regs->arq_head, io_base + IAVF_VF_ARQH1);
+	writel(regs->arq_tail, io_base + IAVF_VF_ARQT1);
+
+	for (i = 0; i < IAVF_QRX_TAIL_MAX; i++)
+		writel(regs->rx_tail[i], io_base + IAVF_QRX_TAIL1(i));
+}
+
+/**
+ * ice_vfio_pci_load_state - VFIO device state reloading
+ * @ice_vdev: pointer to ice vfio pci core device structure
+ *
+ * Load device state and restore it. This function is called when the VFIO uAPI
+ * consumer wants to load the device state info from VFIO migration region and
+ * restore them into the device. This function should make sure all the device
+ * state info is loaded and restored successfully. As a result, return value is
+ * mandatory to be checked.
+ *
+ * Return 0 for success, negative value for failure.
+ */
+static int __must_check
+ice_vfio_pci_load_state(struct ice_vfio_pci_core_device *ice_vdev)
+{
+	struct ice_vfio_pci_migration_file *migf = ice_vdev->resuming_migf;
+
+	ice_vfio_pci_load_regs(ice_vdev, &migf->mig_data.regs);
+	return ice_migration_restore_devstate(ice_vdev->vf_handle,
+					      migf->mig_data.dev_state,
+					      SZ_128K,
+					      &ice_vdev->core_device.vdev);
+}
+
+/**
+ * ice_vfio_pci_save_state - VFIO device state saving
+ * @ice_vdev: pointer to ice vfio pci core device structure
+ * @migf: pointer to migration file
+ *
+ * Snapshot the device state and save it. This function is called when the
+ * VFIO uAPI consumer wants to snapshot the current device state and saves
+ * it into the VFIO migration region. This function should make sure all
+ * of the device state info is collectted and saved successfully. As a
+ * result, return value is mandatory to be checked.
+ *
+ * Return 0 for success, negative value for failure.
+ */
+static int __must_check
+ice_vfio_pci_save_state(struct ice_vfio_pci_core_device *ice_vdev,
+			struct ice_vfio_pci_migration_file *migf)
+{
+	ice_vfio_pci_save_regs(ice_vdev, &migf->mig_data.regs);
+	migf->total_length = SZ_128K;
+
+	return ice_migration_save_devstate(ice_vdev->vf_handle,
+					   migf->mig_data.dev_state,
+					   SZ_128K);
+}
+
+/**
+ * ice_vfio_migration_init - Initialization for live migration function
+ * @ice_vdev: pointer to ice vfio pci core device structure
+ *
+ * Returns 0 on success, negative value on error
+ */
+static int ice_vfio_migration_init(struct ice_vfio_pci_core_device *ice_vdev)
+{
+	struct pci_dev *pdev = ice_vdev->core_device.pdev;
+
+	ice_vdev->vf_handle = ice_migration_get_vf(pdev);
+	if (!ice_vdev->vf_handle)
+		return -EFAULT;
+
+	ice_migration_init_vf(ice_vdev->vf_handle);
+	ice_vdev->io_base = (u8 __iomem *)pci_iomap(pdev, 0, 0);
+	if (!ice_vdev->io_base)
+		return -EFAULT;
+
+	return 0;
+}
+
+/**
+ * ice_vfio_migration_uninit - Cleanup for live migration function
+ * @ice_vdev: pointer to ice vfio pci core device structure
+ */
+static void ice_vfio_migration_uninit(struct ice_vfio_pci_core_device *ice_vdev)
+{
+	pci_iounmap(ice_vdev->core_device.pdev, ice_vdev->io_base);
+	ice_migration_uninit_vf(ice_vdev->vf_handle);
+	ice_migration_put_vf(ice_vdev->vf_handle);
+}
+
+/**
+ * ice_vfio_pci_disable_fd - Close migration file
+ * @migf: pointer to ice vfio pci migration file
+ */
+static void ice_vfio_pci_disable_fd(struct ice_vfio_pci_migration_file *migf)
+{
+	mutex_lock(&migf->lock);
+	migf->disabled = true;
+	migf->total_length = 0;
+	migf->filp->f_pos = 0;
+	mutex_unlock(&migf->lock);
+}
+
+/**
+ * ice_vfio_pci_disable_fds - Close migration files of ice vfio pci device
+ * @ice_vdev: pointer to ice vfio pci core device structure
+ */
+static void ice_vfio_pci_disable_fds(struct ice_vfio_pci_core_device *ice_vdev)
+{
+	if (ice_vdev->resuming_migf) {
+		ice_vfio_pci_disable_fd(ice_vdev->resuming_migf);
+		fput(ice_vdev->resuming_migf->filp);
+		ice_vdev->resuming_migf = NULL;
+	}
+	if (ice_vdev->saving_migf) {
+		ice_vfio_pci_disable_fd(ice_vdev->saving_migf);
+		fput(ice_vdev->saving_migf->filp);
+		ice_vdev->saving_migf = NULL;
+	}
+}
+
+/*
+ * This function is called in all state_mutex unlock cases to
+ * handle a 'deferred_reset' if exists.
+ * @ice_vdev: pointer to ice vfio pci core device structure
+ */
+static void
+ice_vfio_pci_state_mutex_unlock(struct ice_vfio_pci_core_device *ice_vdev)
+{
+again:
+	spin_lock(&ice_vdev->reset_lock);
+	if (ice_vdev->deferred_reset) {
+		ice_vdev->deferred_reset = false;
+		spin_unlock(&ice_vdev->reset_lock);
+		ice_vdev->mig_state = VFIO_DEVICE_STATE_RUNNING;
+		ice_vfio_pci_disable_fds(ice_vdev);
+		goto again;
+	}
+	mutex_unlock(&ice_vdev->state_mutex);
+	spin_unlock(&ice_vdev->reset_lock);
+}
+
+static void ice_vfio_pci_reset_done(struct pci_dev *pdev)
+{
+	struct ice_vfio_pci_core_device *ice_vdev =
+		(struct ice_vfio_pci_core_device *)dev_get_drvdata(&pdev->dev);
+
+	/*
+	 * As the higher VFIO layers are holding locks across reset and using
+	 * those same locks with the mm_lock we need to prevent ABBA deadlock
+	 * with the state_mutex and mm_lock.
+	 * In case the state_mutex was taken already we defer the cleanup work
+	 * to the unlock flow of the other running context.
+	 */
+	spin_lock(&ice_vdev->reset_lock);
+	ice_vdev->deferred_reset = true;
+	if (!mutex_trylock(&ice_vdev->state_mutex)) {
+		spin_unlock(&ice_vdev->reset_lock);
+		return;
+	}
+	spin_unlock(&ice_vdev->reset_lock);
+	ice_vfio_pci_state_mutex_unlock(ice_vdev);
+}
+
+/**
+ * ice_vfio_pci_open_device - Called when a vfio device is probed by VFIO UAPI
+ * @core_vdev: the vfio device to open
+ *
+ * Initialization of the vfio device
+ *
+ * Returns 0 on success, negative value on error
+ */
+static int ice_vfio_pci_open_device(struct vfio_device *core_vdev)
+{
+	struct ice_vfio_pci_core_device *ice_vdev = container_of(core_vdev,
+			struct ice_vfio_pci_core_device, core_device.vdev);
+	struct vfio_pci_core_device *vdev = &ice_vdev->core_device;
+	int ret;
+
+	ret = vfio_pci_core_enable(vdev);
+	if (ret)
+		return ret;
+
+	ret = ice_vfio_migration_init(ice_vdev);
+	if (ret) {
+		vfio_pci_core_disable(vdev);
+		return ret;
+	}
+	ice_vdev->mig_state = VFIO_DEVICE_STATE_RUNNING;
+	vfio_pci_core_finish_enable(vdev);
+
+	return 0;
+}
+
+/**
+ * ice_vfio_pci_close_device - Called when a vfio device fd is closed
+ * @core_vdev: the vfio device to close
+ */
+static void ice_vfio_pci_close_device(struct vfio_device *core_vdev)
+{
+	struct ice_vfio_pci_core_device *ice_vdev = container_of(core_vdev,
+			struct ice_vfio_pci_core_device, core_device.vdev);
+
+	ice_vfio_pci_disable_fds(ice_vdev);
+	vfio_pci_core_close_device(core_vdev);
+	ice_vfio_migration_uninit(ice_vdev);
+}
+
+/**
+ * ice_vfio_pci_release_file - release ice vfio pci migration file
+ * @inode: pointer to inode
+ * @filp: pointer to the file to release
+ *
+ * Return 0 for success, negative for error
+ */
+static int ice_vfio_pci_release_file(struct inode *inode, struct file *filp)
+{
+	struct ice_vfio_pci_migration_file *migf = filp->private_data;
+
+	ice_vfio_pci_disable_fd(migf);
+	mutex_destroy(&migf->lock);
+	kfree(migf);
+	return 0;
+}
+
+/**
+ * ice_vfio_pci_save_read - save migration file data to user space
+ * @filp: pointer to migration file
+ * @buf: pointer to user space buffer
+ * @len: data length to be saved
+ * @pos: should be 0
+ *
+ * Return len of saved data, negative for error
+ */
+static ssize_t ice_vfio_pci_save_read(struct file *filp, char __user *buf,
+				      size_t len, loff_t *pos)
+{
+	struct ice_vfio_pci_migration_file *migf = filp->private_data;
+	loff_t *off = &filp->f_pos;
+	ssize_t done = 0;
+	int ret;
+
+	if (pos)
+		return -ESPIPE;
+
+	mutex_lock(&migf->lock);
+	if (*off > migf->total_length) {
+		done = -EINVAL;
+		goto out_unlock;
+	}
+
+	if (migf->disabled) {
+		done = -ENODEV;
+		goto out_unlock;
+	}
+
+	len = min_t(size_t, migf->total_length - *off, len);
+	if (len) {
+		ret = copy_to_user(buf, (u8 *)(&migf->mig_data) + *off, len);
+		if (ret) {
+			done = -EFAULT;
+			goto out_unlock;
+		}
+		*off += len;
+		done = len;
+	}
+out_unlock:
+	mutex_unlock(&migf->lock);
+	return done;
+}
+
+static const struct file_operations ice_vfio_pci_save_fops = {
+	.owner = THIS_MODULE,
+	.read = ice_vfio_pci_save_read,
+	.release = ice_vfio_pci_release_file,
+	.llseek = no_llseek,
+};
+
+/**
+ * ice_vfio_pci_stop_copy - create migration file and save migration state to it
+ * @ice_vdev: pointer to ice vfio pci core device structure
+ *
+ * Return migration file handler
+ */
+static struct ice_vfio_pci_migration_file *
+ice_vfio_pci_stop_copy(struct ice_vfio_pci_core_device *ice_vdev)
+{
+	struct ice_vfio_pci_migration_file *migf;
+	int ret;
+
+	migf = kzalloc(sizeof(*migf), GFP_KERNEL);
+	if (!migf)
+		return ERR_PTR(-ENOMEM);
+
+	migf->filp = anon_inode_getfile("ice_vfio_pci_mig",
+					&ice_vfio_pci_save_fops, migf,
+					O_RDONLY);
+	if (IS_ERR(migf->filp)) {
+		int err = PTR_ERR(migf->filp);
+
+		kfree(migf);
+		return ERR_PTR(err);
+	}
+
+	stream_open(migf->filp->f_inode, migf->filp);
+	mutex_init(&migf->lock);
+
+	ret = ice_vfio_pci_save_state(ice_vdev, migf);
+	if (ret) {
+		fput(migf->filp);
+		kfree(migf);
+		return ERR_PTR(ret);
+	}
+
+	return migf;
+}
+
+/**
+ * ice_vfio_pci_resume_write- copy migration file data from user space
+ * @filp: pointer to migration file
+ * @buf: pointer to user space buffer
+ * @len: data length to be copied
+ * @pos: should be 0
+ *
+ * Return len of saved data, negative for error
+ */
+static ssize_t
+ice_vfio_pci_resume_write(struct file *filp, const char __user *buf,
+			  size_t len, loff_t *pos)
+{
+	struct ice_vfio_pci_migration_file *migf = filp->private_data;
+	loff_t *off = &filp->f_pos;
+	loff_t requested_length;
+	ssize_t done = 0;
+	int ret;
+
+	if (pos)
+		return -ESPIPE;
+
+	if (*off < 0 ||
+	    check_add_overflow((loff_t)len, *off, &requested_length))
+		return -EINVAL;
+
+	if (requested_length > sizeof(struct ice_vfio_pci_migration_data))
+		return -ENOMEM;
+
+	mutex_lock(&migf->lock);
+	if (migf->disabled) {
+		done = -ENODEV;
+		goto out_unlock;
+	}
+
+	ret = copy_from_user((u8 *)(&migf->mig_data) + *off, buf, len);
+	if (ret) {
+		done = -EFAULT;
+		goto out_unlock;
+	}
+	*off += len;
+	done = len;
+	migf->total_length += len;
+out_unlock:
+	mutex_unlock(&migf->lock);
+	return done;
+}
+
+static const struct file_operations ice_vfio_pci_resume_fops = {
+	.owner = THIS_MODULE,
+	.write = ice_vfio_pci_resume_write,
+	.release = ice_vfio_pci_release_file,
+	.llseek = no_llseek,
+};
+
+/**
+ * ice_vfio_pci_resume - create resuming migration file
+ * @ice_vdev: pointer to ice vfio pci core device structure
+ *
+ * Return migration file handler, negative value for failure
+ */
+static struct ice_vfio_pci_migration_file *
+ice_vfio_pci_resume(struct ice_vfio_pci_core_device *ice_vdev)
+{
+	struct ice_vfio_pci_migration_file *migf;
+
+	migf = kzalloc(sizeof(*migf), GFP_KERNEL);
+	if (!migf)
+		return ERR_PTR(-ENOMEM);
+
+	migf->filp = anon_inode_getfile("ice_vfio_pci_mig",
+					&ice_vfio_pci_resume_fops, migf,
+					O_WRONLY);
+	if (IS_ERR(migf->filp)) {
+		int err = PTR_ERR(migf->filp);
+
+		kfree(migf);
+		return ERR_PTR(err);
+	}
+
+	stream_open(migf->filp->f_inode, migf->filp);
+	mutex_init(&migf->lock);
+	return migf;
+}
+
+/**
+ * ice_vfio_pci_step_device_state_locked - process device state change
+ * @ice_vdev: pointer to ice vfio pci core device structure
+ * @new: new device state
+ * @final: final device state
+ *
+ * Return migration file handler or NULL for success, negative value for failure
+ */
+static struct file *
+ice_vfio_pci_step_device_state_locked(struct ice_vfio_pci_core_device *ice_vdev,
+				      u32 new, u32 final)
+{
+	struct device *dev = &ice_vdev->core_device.pdev->dev;
+	u32 cur = ice_vdev->mig_state;
+	int ret;
+
+	if (final == VFIO_DEVICE_STATE_RESUMING)
+		ice_vdev->is_dst = true;
+	else if (final == VFIO_DEVICE_STATE_STOP)
+		ice_vdev->is_dst = false;
+
+	if (cur == VFIO_DEVICE_STATE_RUNNING && new == VFIO_DEVICE_STATE_STOP) {
+		if (!ice_vdev->is_dst)
+			dev_info(dev, "Live migration begins\n");
+		ice_migration_suspend_vf(ice_vdev->vf_handle, ice_vdev->is_dst);
+		return NULL;
+	}
+
+	if (cur == VFIO_DEVICE_STATE_STOP && new == VFIO_DEVICE_STATE_STOP_COPY) {
+		struct ice_vfio_pci_migration_file *migf;
+
+		migf = ice_vfio_pci_stop_copy(ice_vdev);
+		if (IS_ERR(migf))
+			return ERR_CAST(migf);
+		get_file(migf->filp);
+		ice_vdev->saving_migf = migf;
+		return migf->filp;
+	}
+
+	if (cur == VFIO_DEVICE_STATE_STOP_COPY && new == VFIO_DEVICE_STATE_STOP) {
+		ice_vfio_pci_disable_fds(ice_vdev);
+		dev_info(dev, "Live migration ends\n");
+		return NULL;
+	}
+
+	if (cur == VFIO_DEVICE_STATE_STOP && new == VFIO_DEVICE_STATE_RESUMING) {
+		struct ice_vfio_pci_migration_file *migf;
+
+		migf = ice_vfio_pci_resume(ice_vdev);
+		if (IS_ERR(migf))
+			return ERR_CAST(migf);
+		get_file(migf->filp);
+		ice_vdev->resuming_migf = migf;
+		return migf->filp;
+	}
+
+	if (cur == VFIO_DEVICE_STATE_RESUMING && new == VFIO_DEVICE_STATE_STOP) {
+		ret = ice_vfio_pci_load_state(ice_vdev);
+		if (ret)
+			return ERR_PTR(ret);
+		ice_vfio_pci_disable_fds(ice_vdev);
+		return NULL;
+	}
+
+	if (cur == VFIO_DEVICE_STATE_STOP && new == VFIO_DEVICE_STATE_RUNNING)
+		return NULL;
+
+	/*
+	 * vfio_mig_get_next_state() does not use arcs other than the above
+	 */
+	WARN_ON(true);
+	return ERR_PTR(-EINVAL);
+}
+
+/**
+ * ice_vfio_pci_set_device_state - Config device state
+ * @vdev: pointer to vfio pci device
+ * @new_state: device state
+ *
+ * Return 0 for success, negative value for failure.
+ */
+static struct file *
+ice_vfio_pci_set_device_state(struct vfio_device *vdev,
+			    enum vfio_device_mig_state new_state)
+{
+	struct ice_vfio_pci_core_device *ice_vdev = container_of(
+		vdev, struct ice_vfio_pci_core_device, core_device.vdev);
+	enum vfio_device_mig_state next_state;
+	struct file *res = NULL;
+	int ret;
+
+	mutex_lock(&ice_vdev->state_mutex);
+	while (new_state != ice_vdev->mig_state) {
+		ret = vfio_mig_get_next_state(vdev, ice_vdev->mig_state,
+					      new_state, &next_state);
+		if (ret) {
+			res = ERR_PTR(ret);
+			break;
+		}
+		res = ice_vfio_pci_step_device_state_locked(ice_vdev, next_state,
+							    new_state);
+		if (IS_ERR(res))
+			break;
+		ice_vdev->mig_state = next_state;
+		if (WARN_ON(res && new_state != ice_vdev->mig_state)) {
+			fput(res);
+			res = ERR_PTR(-EINVAL);
+			break;
+		}
+	}
+	ice_vfio_pci_state_mutex_unlock(ice_vdev);
+	return res;
+}
+
+/**
+ * ice_vfio_pci_get_device_state - get device state
+ * @vdev: pointer to vfio pci device
+ * @curr_state: device state
+ *
+ * Return 0 for success
+ */
+static int ice_vfio_pci_get_device_state(struct vfio_device *vdev,
+					 enum vfio_device_mig_state *curr_state)
+{
+	struct ice_vfio_pci_core_device *ice_vdev = container_of(
+		vdev, struct ice_vfio_pci_core_device, core_device.vdev);
+
+	mutex_lock(&ice_vdev->state_mutex);
+	*curr_state = ice_vdev->mig_state;
+	ice_vfio_pci_state_mutex_unlock(ice_vdev);
+	return 0;
+}
+
+/**
+ * ice_vfio_pci_get_data_size - get migration data size
+ * @vdev: pointer to vfio pci device
+ * @stop_copy_length: migration data size
+ *
+ * Return 0 for success
+ */
+static int
+ice_vfio_pci_get_data_size(struct vfio_device *vdev,
+			   unsigned long *stop_copy_length)
+{
+	*stop_copy_length = SZ_128K;
+	return 0;
+}
+
+static const struct vfio_migration_ops ice_vfio_pci_migrn_state_ops = {
+	.migration_set_state = ice_vfio_pci_set_device_state,
+	.migration_get_state = ice_vfio_pci_get_device_state,
+	.migration_get_data_size = ice_vfio_pci_get_data_size,
+};
+
+/**
+ * ice_vfio_pci_core_init_dev - initialize vfio device
+ * @core_vdev: pointer to vfio device
+ *
+ * Return 0 for success
+ */
+static int ice_vfio_pci_core_init_dev(struct vfio_device *core_vdev)
+{
+	struct ice_vfio_pci_core_device *ice_vdev = container_of(core_vdev,
+			struct ice_vfio_pci_core_device, core_device.vdev);
+
+	mutex_init(&ice_vdev->state_mutex);
+	spin_lock_init(&ice_vdev->reset_lock);
+
+	core_vdev->migration_flags = VFIO_MIGRATION_STOP_COPY;
+	core_vdev->mig_ops = &ice_vfio_pci_migrn_state_ops;
+
+	return vfio_pci_core_init_dev(core_vdev);
+}
+
+static const struct vfio_device_ops ice_vfio_pci_ops = {
+	.name		= "ice-vfio-pci",
+	.init		= ice_vfio_pci_core_init_dev,
+	.release	= vfio_pci_core_release_dev,
+	.open_device	= ice_vfio_pci_open_device,
+	.close_device	= ice_vfio_pci_close_device,
+	.device_feature = vfio_pci_core_ioctl_feature,
+	.read		= vfio_pci_core_read,
+	.write		= vfio_pci_core_write,
+	.ioctl		= vfio_pci_core_ioctl,
+	.mmap		= vfio_pci_core_mmap,
+	.request	= vfio_pci_core_request,
+	.match		= vfio_pci_core_match,
+	.bind_iommufd	= vfio_iommufd_physical_bind,
+	.unbind_iommufd	= vfio_iommufd_physical_unbind,
+	.attach_ioas	= vfio_iommufd_physical_attach_ioas,
+};
+
+/**
+ * ice_vfio_pci_probe - Device initialization routine
+ * @pdev: PCI device information struct
+ * @id: entry in ice_vfio_pci_table
+ *
+ * Returns 0 on success, negative on failure
+ */
+static int
+ice_vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
+{
+	struct ice_vfio_pci_core_device *ice_vdev;
+	int ret;
+
+	ice_vdev = vfio_alloc_device(ice_vfio_pci_core_device, core_device.vdev,
+					&pdev->dev, &ice_vfio_pci_ops);
+	if (!ice_vdev)
+		return -ENOMEM;
+
+	dev_set_drvdata(&pdev->dev, &ice_vdev->core_device);
+
+	ret = vfio_pci_core_register_device(&ice_vdev->core_device);
+	if (ret)
+		goto out_free;
+
+	return 0;
+
+out_free:
+	vfio_put_device(&ice_vdev->core_device.vdev);
+	return ret;
+}
+
+/**
+ * ice_vfio_pci_remove - Device removal routine
+ * @pdev: PCI device information struct
+ */
+static void ice_vfio_pci_remove(struct pci_dev *pdev)
+{
+	struct ice_vfio_pci_core_device *ice_vdev =
+		(struct ice_vfio_pci_core_device *)dev_get_drvdata(&pdev->dev);
+
+	vfio_pci_core_unregister_device(&ice_vdev->core_device);
+	vfio_put_device(&ice_vdev->core_device.vdev);
+}
+
+/* ice_pci_tbl - PCI Device ID Table
+ *
+ * Wildcard entries (PCI_ANY_ID) should come last
+ * Last entry must be all 0s
+ *
+ * { Vendor ID, Device ID, SubVendor ID, SubDevice ID,
+ *   Class, Class Mask, private data (not used) }
+ */
+static const struct pci_device_id ice_vfio_pci_table[] = {
+	{ PCI_DRIVER_OVERRIDE_DEVICE_VFIO(PCI_VENDOR_ID_INTEL, 0x1889) },
+	{}
+};
+MODULE_DEVICE_TABLE(pci, ice_vfio_pci_table);
+
+static const struct pci_error_handlers ice_vfio_pci_core_err_handlers = {
+	.reset_done = ice_vfio_pci_reset_done,
+	.error_detected = vfio_pci_core_aer_err_detected,
+};
+
+static struct pci_driver ice_vfio_pci_driver = {
+	.name			= "ice-vfio-pci",
+	.id_table		= ice_vfio_pci_table,
+	.probe			= ice_vfio_pci_probe,
+	.remove			= ice_vfio_pci_remove,
+	.err_handler            = &ice_vfio_pci_core_err_handlers,
+	.driver_managed_dma	= true,
+};
+
+module_pci_driver(ice_vfio_pci_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Intel Corporation, <linux.nics@intel.com>");
+MODULE_DESCRIPTION(DRIVER_DESC);
-- 
2.25.1

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