diff options
| author | Sumit Semwal <sumit.semwal@linaro.org> | 2017-03-25 21:48:09 +0530 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-03-30 09:35:19 +0200 |
| commit | 131f7969048b8ede0be57f64930e9ef8fee0c53b (patch) | |
| tree | f8648537a140e3f42013794dd753ffcf5e397f72 | |
| parent | 40a85d68185f9d9e7d370919f8a3532b0d259266 (diff) | |
PCI: Don't update VF BARs while VF memory space is enabled
From: Bjorn Helgaas <bhelgaas@google.com>
[ Upstream commit 546ba9f8f22f71b0202b6ba8967be5cc6dae4e21 ]
If we update a VF BAR while it's enabled, there are two potential problems:
1) Any driver that's using the VF has a cached BAR value that is stale
after the update, and
2) We can't update 64-bit BARs atomically, so the intermediate state
(new lower dword with old upper dword) may conflict with another
device, and an access by a driver unrelated to the VF may cause a bus
error.
Warn about attempts to update VF BARs while they are enabled. This is a
programming error, so use dev_WARN() to get a backtrace.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/pci/iov.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c index 2f8ea6f84c97..47c46d07f110 100644 --- a/drivers/pci/iov.c +++ b/drivers/pci/iov.c @@ -567,6 +567,7 @@ void pci_iov_update_resource(struct pci_dev *dev, int resno) struct resource *res = dev->resource + resno; int vf_bar = resno - PCI_IOV_RESOURCES; struct pci_bus_region region; + u16 cmd; u32 new; int reg; @@ -578,6 +579,13 @@ void pci_iov_update_resource(struct pci_dev *dev, int resno) if (!iov) return; + pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &cmd); + if ((cmd & PCI_SRIOV_CTRL_VFE) && (cmd & PCI_SRIOV_CTRL_MSE)) { + dev_WARN(&dev->dev, "can't update enabled VF BAR%d %pR\n", + vf_bar, res); + return; + } + /* * Ignore unimplemented BARs, unused resource slots for 64-bit * BARs, and non-movable resources, e.g., those described via |