[PATCH RFC 10/11] nvmet: Add addr fam and trtype for mdev pci driver

[Mike Christie]

This allocates 253 for mdev pci since it might not fit into any
existing value (not sure how to co-exist with pci-epf).

One of the reasons this patchset is a RFC is because I was not sure
if allocating a new number for this was the best. Another approach
is that I could break up pci-epf into a:

1. PCI component - Common PCI and NVMe PCI code.
2. Interface/bus component - Callouts so pci-epf can use the
pci_epf_driver/pci_epf_ops and mdev-pci can use mdev and vfio
callouts.
3. Memory management component - Callouts for using DMA for pci-epf
vs vfio related memory for mdev-pci.

On one hand, by creating a core nvmet pci driver then have subdrivers
we could share NVMF_ADDR_FAMILY_PCI and NVMF_TRTYPE_PCI. However,
it will get messy. There is some PCI code we could share for 1
but 2 and 3 will make sharing difficult becuse of how different the
drivers work (mdev-vfio vs pci-epf layers).

Signed-off-by: Mike Christie <michael.christie at oracle.com>
---
 drivers/nvme/target/configfs.c |  1 +
 drivers/nvme/target/nvmet.h    |  5 ++++-
 include/linux/nvme.h           | 14 ++++++++------
 3 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c
index 31c484d51a69..73bab15506c2 100644
--- a/drivers/nvme/target/configfs.c
+++ b/drivers/nvme/target/configfs.c
@@ -39,6 +39,7 @@ static struct nvmet_type_name_map nvmet_transport[] = {
 	{ NVMF_TRTYPE_TCP,	"tcp" },
 	{ NVMF_TRTYPE_PCI,	"pci" },
 	{ NVMF_TRTYPE_LOOP,	"loop" },
+	{ NVMF_TRTYPE_MDEV_PCI,	"mdev-pci" },
 };
 
 static const struct nvmet_type_name_map nvmet_addr_family[] = {
diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
index a16d1c74e3d9..6c825177ee87 100644
--- a/drivers/nvme/target/nvmet.h
+++ b/drivers/nvme/target/nvmet.h
@@ -755,7 +755,10 @@ static inline bool nvmet_is_disc_subsys(struct nvmet_subsys *subsys)
 
 static inline bool nvmet_is_pci_ctrl(struct nvmet_ctrl *ctrl)
 {
-	return ctrl->port->disc_addr.trtype == NVMF_TRTYPE_PCI;
+	struct nvmf_disc_rsp_page_entry *addr = &ctrl->port->disc_addr;
+
+	return addr->trtype == NVMF_TRTYPE_PCI ||
+	       addr->trtype == NVMF_TRTYPE_MDEV_PCI;
 }
 
 #ifdef CONFIG_NVME_TARGET_PASSTHRU
diff --git a/include/linux/nvme.h b/include/linux/nvme.h
index a7b8bcef20fb..994f02158078 100644
--- a/include/linux/nvme.h
+++ b/include/linux/nvme.h
@@ -53,12 +53,13 @@ enum nvme_dctype {
 
 /* Address Family codes for Discovery Log Page entry ADRFAM field */
 enum {
-	NVMF_ADDR_FAMILY_PCI	= 0,	/* PCIe */
-	NVMF_ADDR_FAMILY_IP4	= 1,	/* IP4 */
-	NVMF_ADDR_FAMILY_IP6	= 2,	/* IP6 */
-	NVMF_ADDR_FAMILY_IB	= 3,	/* InfiniBand */
-	NVMF_ADDR_FAMILY_FC	= 4,	/* Fibre Channel */
-	NVMF_ADDR_FAMILY_LOOP	= 254,	/* Reserved for host usage */
+	NVMF_ADDR_FAMILY_PCI		= 0,	/* PCIe */
+	NVMF_ADDR_FAMILY_IP4		= 1,	/* IP4 */
+	NVMF_ADDR_FAMILY_IP6		= 2,	/* IP6 */
+	NVMF_ADDR_FAMILY_IB		= 3,	/* InfiniBand */
+	NVMF_ADDR_FAMILY_FC		= 4,	/* Fibre Channel */
+	NVMF_ADDR_FAMILY_MDEV_PCI	= 253,	/* MDEV PCI */
+	NVMF_ADDR_FAMILY_LOOP		= 254,	/* Reserved for host usage */
 	NVMF_ADDR_FAMILY_MAX,
 };
 
@@ -68,6 +69,7 @@ enum {
 	NVMF_TRTYPE_RDMA	= 1,	/* RDMA */
 	NVMF_TRTYPE_FC		= 2,	/* Fibre Channel */
 	NVMF_TRTYPE_TCP		= 3,	/* TCP/IP */
+	NVMF_TRTYPE_MDEV_PCI	= 253,	/* MDEV PCI hack */
 	NVMF_TRTYPE_LOOP	= 254,	/* Reserved for host usage */
 	NVMF_TRTYPE_MAX,
 };
-- 
2.43.0