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. Tested-by: Donald Dutile <ddutile@xxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
