On 10/11/2011 09:37 AM, Prarit Bhargava wrote:
To help debugging, add a kernel parameter, pci=nosriov which disables SRIOV.
[v2]: Jes Sorensen noticed typos in the descriptions of the nosriov
parameter.
Tested on x86 platforms with sriov-capable bios, iommu's and 82599 & 82576.
VFs not enabled when drivers loaded with max_vfs set, and no error messages.
cat /proc/iomem with and without nosriov generate output without and with
VF resources, respectively.
Given goal and testing results.
Signed-off-by: Donald Dutile <ddutile@xxxxxxxxxx>
Signed-off-by: Prarit Bhargava<prarit@xxxxxxxxxx>
Cc: ddutile@xxxxxxxxxx
Cc: bhelgaas@xxxxxxxxxx
---
Documentation/kernel-parameters.txt | 3 +++
drivers/pci/iov.c | 19 ++++++++++++++++++-
drivers/pci/pci.c | 2 ++
drivers/pci/pci.h | 3 +++
4 files changed, 26 insertions(+), 1 deletions(-)
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 854ed5c..b528f5f 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -2032,6 +2032,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
on: Turn ECRC on.
realloc reallocate PCI resources if allocations done by BIOS
are erroneous.
+ nosriov [HW]
+ Disable SRIOV support in kernel.
+ Please report a bug if you use this parameter.
pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power
Management.
diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 42fae47..260c94d 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -408,6 +408,8 @@ static void sriov_disable(struct pci_dev *dev)
iov->nr_virtfn = 0;
}
+unsigned int pci_sriov_enabled = 1;
+
static int sriov_init(struct pci_dev *dev, int pos)
{
int i;
@@ -419,6 +421,12 @@ static int sriov_init(struct pci_dev *dev, int pos)
struct resource *res;
struct pci_dev *pdev;
+ if (!pci_sriov_enabled) {
+ rc = -EPERM;
+ /* in theory no flags should have been set ... */
+ goto failed;
+ }
+
if (dev->pcie_type != PCI_EXP_TYPE_RC_END&&
dev->pcie_type != PCI_EXP_TYPE_ENDPOINT)
return -ENODEV;
@@ -614,7 +622,10 @@ resource_size_t pci_sriov_resource_alignment(struct pci_dev *dev, int resno)
struct resource tmp;
enum pci_bar_type type;
int reg = pci_iov_resource_bar(dev, resno,&type);
-
+
+ if (!pci_sriov_enabled)
+ return 0;
+
if (!reg)
return 0;
@@ -667,6 +678,9 @@ int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
{
might_sleep();
+ if (!pci_sriov_enabled)
+ return -EPERM;
+
if (!dev->is_physfn)
return -ENODEV;
@@ -682,6 +696,9 @@ void pci_disable_sriov(struct pci_dev *dev)
{
might_sleep();
+ if (!pci_sriov_enabled)
+ return;
+
if (!dev->is_physfn)
return;
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index e9651f0..11175cb 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -3576,6 +3576,8 @@ static int __init pci_setup(char *str)
pcie_bus_config = PCIE_BUS_PERFORMANCE;
} else if (!strncmp(str, "pcie_bus_peer2peer", 18)) {
pcie_bus_config = PCIE_BUS_PEER2PEER;
+ } else if (!strncmp(str, "nosriov", 7)) {
+ pci_sriov_enabled = 0;
} else {
printk(KERN_ERR "PCI: Unknown option `%s'\n",
str);
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index b74084e..9eeb56d 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -229,6 +229,9 @@ resource_size_t pci_specified_resource_alignment(struct pci_dev *dev);
extern void pci_disable_bridge_window(struct pci_dev *dev);
#endif
+/* Use "pci=nosriov" to disable SRIOV */
+extern unsigned int pci_sriov_enabled;
+
/* Single Root I/O Virtualization */
struct pci_sriov {
int pos; /* capability position */
--
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