From 70675e0b6a1ae20f8e93f9fc083d28034ad38948 Mon Sep 17 00:00:00 2001 From: Wei Yang Date: Wed, 29 Jul 2015 16:52:58 +0800 Subject: [PATCH] PCI: Don't try to restore VF BARs VF BARs are read-only zero, so updating VF BARs will not have any effect. See the SR-IOV spec r1.1, sec 3.4.1.11. Don't update VF BARs in pci_restore_bars(). This avoids spurious "BAR %d: error updating" messages that we see when doing vfio pass-through after 6eb7018705de ("vfio-pci: Move idle devices to D3hot power state"). [bhelgaas: changelog, fix whitespace] Signed-off-by: Wei Yang Signed-off-by: Bjorn Helgaas --- drivers/pci/pci.c | 6 +++++- drivers/pci/setup-res.c | 5 +++++ 2 files changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 6a9a1116f1eb..1cfb47a9a9ff 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -484,7 +484,7 @@ int pci_wait_for_pending(struct pci_dev *dev, int pos, u16 mask) } /** - * pci_restore_bars - restore a devices BAR values (e.g. after wake-up) + * pci_restore_bars - restore a device's BAR values (e.g. after wake-up) * @dev: PCI device to have its BARs restored * * Restore the BAR values for a given device, so as to make it @@ -494,6 +494,10 @@ static void pci_restore_bars(struct pci_dev *dev) { int i; + /* Per SR-IOV spec 3.4.1.11, VF BARs are RO zero */ + if (dev->is_virtfn) + return; + for (i = 0; i < PCI_BRIDGE_RESOURCES; i++) pci_update_resource(dev, i); } diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c index 232f9254c11a..152de5cd1cfc 100644 --- a/drivers/pci/setup-res.c +++ b/drivers/pci/setup-res.c @@ -36,6 +36,11 @@ void pci_update_resource(struct pci_dev *dev, int resno) enum pci_bar_type type; struct resource *res = dev->resource + resno; + if (dev->is_virtfn) { + dev_warn(&dev->dev, "can't update VF BAR%d\n", resno); + return; + } + /* * Ignore resources for unimplemented BARs and unused resource slots * for 64 bit BARs.