On 12/06/2011 02:51 AM, Ram Pai wrote:
On Mon, Dec 05, 2011 at 04:25:02PM -0500, Don Dutile wrote:
On 12/05/2011 01:17 PM, Jesse Barnes wrote:
On Sun, 6 Nov 2011 10:33:57 +0800
Ram Pai<linuxram@xxxxxxxxxx> wrote:
The SRIOV capability, namely page size and total_vfs of a device are
configured during enumeration phase of the device.
This can potentially interfere with the PCI operations of the platform,
if the IOV capability of the device is not enabled.
The following patch postpones the configuration of the IOV capability of the
device to a later point, when the IOV capability is explicitly enabled
by the device driver.
The patch is tested on x86 and power platform.
Signed-off-by: Ram Pai<linuxram@xxxxxxxxxx>
---
drivers/pci/iov.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index b0446dd..c1a6f5c 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -346,6 +346,8 @@ static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
return rc;
}
+ pci_write_config_dword(dev, iov->pos + PCI_SRIOV_SYS_PGSIZE, iov->pgsz);
+
iov->ctrl |= PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE;
pci_block_user_cfg_access(dev);
pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
@@ -451,7 +453,6 @@ static int sriov_init(struct pci_dev *dev, int pos)
found:
pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl);
- pci_write_config_word(dev, pos + PCI_SRIOV_NUM_VF, total);
pci_read_config_word(dev, pos + PCI_SRIOV_VF_OFFSET,&offset);
pci_read_config_word(dev, pos + PCI_SRIOV_VF_STRIDE,&stride);
if (!offset || (total> 1&& !stride))
@@ -464,7 +465,6 @@ found:
return -EIO;
pgsz&= ~(pgsz - 1);
- pci_write_config_dword(dev, pos + PCI_SRIOV_SYS_PGSIZE, pgsz);
nres = 0;
for (i = 0; i< PCI_SRIOV_NUM_BARS; i++) {
Anyone want to volunteer a tested-by for this one?
Thanks,
I tested this patch along with Ram's other recent patch for SRIOV:
[RFC PATCH 1/1]PCI: defer enablement of SRIOV BARS
With or without this patch, device assignment to a KVM guest
using these patches worked for me. I used one PF in a quad-function
i350, configuring 2 VFs per i350. I did 4 assign/deassigns to make
sure multiple enable/disables worked.
So, the patch doesn't correct any error I was seeing,
but it doesn't cause any regression either.
Thanks Don for your tested-by.
I recollect you had a issue, which I thought were not related or
addressed by my patches. If I can get a dmesg of your machine, I probably will
be able to see the relation.
RP
My issue was more RHEL specific. Your patches appear to resolve the issues
in a more general manner, and one that saner (to me... delay SRIOV resource allocation
and setup until a driver is actually enabled with it, instead of always on no matter
what the system use of SRIOV is).
- Don
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