vfio/pds: Add VFIO live migration support

Add live migration support via the VFIO subsystem. The migration
implementation aligns with the definition from uapi/vfio.h and uses
the pds_core PF's adminq for device configuration.

The ability to suspend, resume, and transfer VF device state data is
included along with the required admin queue command structures and
implementations.

PDS_LM_CMD_SUSPEND and PDS_LM_CMD_SUSPEND_STATUS are added to support
the VF device suspend operation.

PDS_LM_CMD_RESUME is added to support the VF device resume operation.

PDS_LM_CMD_STATE_SIZE is added to determine the exact size of the VF
device state data.

PDS_LM_CMD_SAVE is added to get the VF device state data.

PDS_LM_CMD_RESTORE is added to restore the VF device with the
previously saved data from PDS_LM_CMD_SAVE.

PDS_LM_CMD_HOST_VF_STATUS is added to notify the DSC/firmware when
a migration is in/not-in progress from the host's perspective. The
DSC/firmware can use this to clear/setup any necessary state related
to a migration.

Signed-off-by: Brett Creeley <brett.creeley@amd.com>
Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20230807205755.29579-6-brett.creeley@amd.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

1 files changed, 197 insertions, 0 deletions

diff --git a/include/linux/pds/pds_adminq.h b/include/linux/pds/pds_adminq.h
index bcba7fda3cc9..9c79b3c8fc47 100644
--- a/include/linux/pds/pds_adminq.h
+++ b/include/linux/pds/pds_adminq.h
@@ -818,6 +818,194 @@ struct pds_vdpa_set_features_cmd {
 	__le64 features;
 };
 
+#define PDS_LM_DEVICE_STATE_LENGTH		65536
+#define PDS_LM_CHECK_DEVICE_STATE_LENGTH(X) \
+			PDS_CORE_SIZE_CHECK(union, PDS_LM_DEVICE_STATE_LENGTH, X)
+
+/*
+ * enum pds_lm_cmd_opcode - Live Migration Device commands
+ */
+enum pds_lm_cmd_opcode {
+	PDS_LM_CMD_HOST_VF_STATUS  = 1,
+
+	/* Device state commands */
+	PDS_LM_CMD_STATE_SIZE	   = 16,
+	PDS_LM_CMD_SUSPEND         = 18,
+	PDS_LM_CMD_SUSPEND_STATUS  = 19,
+	PDS_LM_CMD_RESUME          = 20,
+	PDS_LM_CMD_SAVE            = 21,
+	PDS_LM_CMD_RESTORE         = 22,
+};
+
+/**
+ * struct pds_lm_cmd - generic command
+ * @opcode:	Opcode
+ * @rsvd:	Word boundary padding
+ * @vf_id:	VF id
+ * @rsvd2:	Structure padding to 60 Bytes
+ */
+struct pds_lm_cmd {
+	u8     opcode;
+	u8     rsvd;
+	__le16 vf_id;
+	u8     rsvd2[56];
+};
+
+/**
+ * struct pds_lm_state_size_cmd - STATE_SIZE command
+ * @opcode:	Opcode
+ * @rsvd:	Word boundary padding
+ * @vf_id:	VF id
+ */
+struct pds_lm_state_size_cmd {
+	u8     opcode;
+	u8     rsvd;
+	__le16 vf_id;
+};
+
+/**
+ * struct pds_lm_state_size_comp - STATE_SIZE command completion
+ * @status:		Status of the command (enum pds_core_status_code)
+ * @rsvd:		Word boundary padding
+ * @comp_index:		Index in the desc ring for which this is the completion
+ * @size:		Size of the device state
+ * @rsvd2:		Word boundary padding
+ * @color:		Color bit
+ */
+struct pds_lm_state_size_comp {
+	u8     status;
+	u8     rsvd;
+	__le16 comp_index;
+	union {
+		__le64 size;
+		u8     rsvd2[11];
+	} __packed;
+	u8     color;
+};
+
+enum pds_lm_suspend_resume_type {
+	PDS_LM_SUSPEND_RESUME_TYPE_FULL = 0,
+	PDS_LM_SUSPEND_RESUME_TYPE_P2P = 1,
+};
+
+/**
+ * struct pds_lm_suspend_cmd - SUSPEND command
+ * @opcode:	Opcode PDS_LM_CMD_SUSPEND
+ * @rsvd:	Word boundary padding
+ * @vf_id:	VF id
+ * @type:	Type of suspend (enum pds_lm_suspend_resume_type)
+ */
+struct pds_lm_suspend_cmd {
+	u8     opcode;
+	u8     rsvd;
+	__le16 vf_id;
+	u8     type;
+};
+
+/**
+ * struct pds_lm_suspend_status_cmd - SUSPEND status command
+ * @opcode:	Opcode PDS_AQ_CMD_LM_SUSPEND_STATUS
+ * @rsvd:	Word boundary padding
+ * @vf_id:	VF id
+ * @type:	Type of suspend (enum pds_lm_suspend_resume_type)
+ */
+struct pds_lm_suspend_status_cmd {
+	u8 opcode;
+	u8 rsvd;
+	__le16 vf_id;
+	u8 type;
+};
+
+/**
+ * struct pds_lm_resume_cmd - RESUME command
+ * @opcode:	Opcode PDS_LM_CMD_RESUME
+ * @rsvd:	Word boundary padding
+ * @vf_id:	VF id
+ * @type:	Type of resume (enum pds_lm_suspend_resume_type)
+ */
+struct pds_lm_resume_cmd {
+	u8     opcode;
+	u8     rsvd;
+	__le16 vf_id;
+	u8     type;
+};
+
+/**
+ * struct pds_lm_sg_elem - Transmit scatter-gather (SG) descriptor element
+ * @addr:	DMA address of SG element data buffer
+ * @len:	Length of SG element data buffer, in bytes
+ * @rsvd:	Word boundary padding
+ */
+struct pds_lm_sg_elem {
+	__le64 addr;
+	__le32 len;
+	__le16 rsvd[2];
+};
+
+/**
+ * struct pds_lm_save_cmd - SAVE command
+ * @opcode:	Opcode PDS_LM_CMD_SAVE
+ * @rsvd:	Word boundary padding
+ * @vf_id:	VF id
+ * @rsvd2:	Word boundary padding
+ * @sgl_addr:	IOVA address of the SGL to dma the device state
+ * @num_sge:	Total number of SG elements
+ */
+struct pds_lm_save_cmd {
+	u8     opcode;
+	u8     rsvd;
+	__le16 vf_id;
+	u8     rsvd2[4];
+	__le64 sgl_addr;
+	__le32 num_sge;
+} __packed;
+
+/**
+ * struct pds_lm_restore_cmd - RESTORE command
+ * @opcode:	Opcode PDS_LM_CMD_RESTORE
+ * @rsvd:	Word boundary padding
+ * @vf_id:	VF id
+ * @rsvd2:	Word boundary padding
+ * @sgl_addr:	IOVA address of the SGL to dma the device state
+ * @num_sge:	Total number of SG elements
+ */
+struct pds_lm_restore_cmd {
+	u8     opcode;
+	u8     rsvd;
+	__le16 vf_id;
+	u8     rsvd2[4];
+	__le64 sgl_addr;
+	__le32 num_sge;
+} __packed;
+
+/**
+ * union pds_lm_dev_state - device state information
+ * @words:	Device state words
+ */
+union pds_lm_dev_state {
+	__le32 words[PDS_LM_DEVICE_STATE_LENGTH / sizeof(__le32)];
+};
+
+enum pds_lm_host_vf_status {
+	PDS_LM_STA_NONE = 0,
+	PDS_LM_STA_IN_PROGRESS,
+	PDS_LM_STA_MAX,
+};
+
+/**
+ * struct pds_lm_host_vf_status_cmd - HOST_VF_STATUS command
+ * @opcode:	Opcode PDS_LM_CMD_HOST_VF_STATUS
+ * @rsvd:	Word boundary padding
+ * @vf_id:	VF id
+ * @status:	Current LM status of host VF driver (enum pds_lm_host_status)
+ */
+struct pds_lm_host_vf_status_cmd {
+	u8     opcode;
+	u8     rsvd;
+	__le16 vf_id;
+	u8     status;
+};
+
 union pds_core_adminq_cmd {
 	u8     opcode;
 	u8     bytes[64];
@@ -844,6 +1032,13 @@ union pds_core_adminq_cmd {
 	struct pds_vdpa_vq_init_cmd	  vdpa_vq_init;
 	struct pds_vdpa_vq_reset_cmd	  vdpa_vq_reset;
 
+	struct pds_lm_suspend_cmd	  lm_suspend;
+	struct pds_lm_suspend_status_cmd  lm_suspend_status;
+	struct pds_lm_resume_cmd	  lm_resume;
+	struct pds_lm_state_size_cmd	  lm_state_size;
+	struct pds_lm_save_cmd		  lm_save;
+	struct pds_lm_restore_cmd	  lm_restore;
+	struct pds_lm_host_vf_status_cmd  lm_host_vf_status;
 };
 
 union pds_core_adminq_comp {
@@ -868,6 +1063,8 @@ union pds_core_adminq_comp {
 
 	struct pds_vdpa_vq_init_comp	  vdpa_vq_init;
 	struct pds_vdpa_vq_reset_comp	  vdpa_vq_reset;
+
+	struct pds_lm_state_size_comp	  lm_state_size;
 };
 
 #ifndef __CHECKER__