[RFC 08/12] PCI: Add is_sriov bit to struct pci_dev

[Dimitri Daskalakis <dimitri.daskalakis1@gmail.com>]

From: Dimitri Daskalakis <daskald@meta.com>

We need a way to disambiguate the virtualization type of a PF/VF.
PFs may support multiple types of virtualization, while a VF should
only support one.

Tighten pci_is_sriov_physfn() / pci_is_sriov_virtfn() to ensure the
is_sriov bit is set. This allows the existing is_physfn/is_virtfn
bits to be agnostic of virtualization type.

No functional changes for SR-IOV.

Assisted-by: Claude:claude-opus-4.7
Signed-off-by: Dimitri Daskalakis <daskald@meta.com>
---
 arch/s390/pci/pci_iov.c | 1 +
 drivers/pci/iov.c       | 4 ++++
 include/linux/pci.h     | 5 +++--
 3 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/arch/s390/pci/pci_iov.c b/arch/s390/pci/pci_iov.c
index 13050ce5c3e9..82e9ef1f132f 100644
--- a/arch/s390/pci/pci_iov.c
+++ b/arch/s390/pci/pci_iov.c
@@ -53,6 +53,7 @@ static int zpci_iov_link_virtfn(struct pci_dev *pdev, struct pci_dev *virtfn, in
 		return rc;
 
 	virtfn->is_virtfn = 1;
+	virtfn->is_sriov = 1;
 	virtfn->multifunction = 0;
 	virtfn->physfn = pci_dev_get(pdev);
 
diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 5de26057b99a..4aed4f6a42c3 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -326,6 +326,7 @@ static struct pci_dev *pci_iov_scan_device(struct pci_dev *dev, int id,
 	virtfn->vendor = dev->vendor;
 	virtfn->device = iov->vf_device;
 	virtfn->is_virtfn = 1;
+	virtfn->is_sriov = 1;
 	virtfn->physfn = pci_dev_get(dev);
 	virtfn->no_command_memory = 1;
 
@@ -897,6 +898,7 @@ static int sriov_init(struct pci_dev *dev, int pos)
 		iov->dev = dev;
 
 	dev->sriov = iov;
+	dev->is_sriov = 1;
 	dev->is_physfn = 1;
 	rc = compute_max_vf_buses(dev);
 	if (rc)
@@ -906,6 +908,7 @@ static int sriov_init(struct pci_dev *dev, int pos)
 
 fail_max_buses:
 	dev->sriov = NULL;
+	dev->is_sriov = 0;
 	dev->is_physfn = 0;
 failed:
 	for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
@@ -926,6 +929,7 @@ static void sriov_release(struct pci_dev *dev)
 
 	kfree(dev->sriov);
 	dev->sriov = NULL;
+	dev->is_sriov = 0;
 }
 
 static void sriov_restore_vf_rebar_state(struct pci_dev *dev)
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 28892243f49f..ca84f66425b2 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -479,6 +479,7 @@ struct pci_dev {
 	unsigned int	state_saved:1;
 	unsigned int	is_physfn:1;
 	unsigned int	is_virtfn:1;
+	unsigned int	is_sriov:1;		/* SR-IOV is enabled on this device (PF or VF) */
 	unsigned int	is_hotplug_bridge:1;
 	unsigned int	is_pciehp:1;
 	unsigned int	shpc_managed:1;		/* SHPC owned by shpchp */
@@ -606,12 +607,12 @@ static inline struct pci_dev *pci_physfn(struct pci_dev *dev)
 
 static inline bool pci_is_sriov_physfn(const struct pci_dev *dev)
 {
-	return dev->is_physfn;
+	return dev->is_physfn && dev->is_sriov;
 }
 
 static inline bool pci_is_sriov_virtfn(const struct pci_dev *dev)
 {
-	return dev->is_virtfn;
+	return dev->is_virtfn && dev->is_sriov;
 }
 
 struct pci_dev *pci_alloc_dev(struct pci_bus *bus);
-- 
2.52.0