This is a note to let you know that I've just added the patch titled
PCI: Don't update VF BARs while VF memory space is enabled
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
pci-don-t-update-vf-bars-while-vf-memory-space-is-enabled.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Tue Mar 28 13:59:27 CEST 2017
From: Sumit Semwal <sumit.semwal@xxxxxxxxxx>
Date: Sat, 25 Mar 2017 21:48:09 +0530
Subject: PCI: Don't update VF BARs while VF memory space is enabled
To: stable@xxxxxxxxxxxxxxx
Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>, Sasha Levin <alexander.levin@xxxxxxxxxxx>, Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>, Sumit Semwal <sumit.semwal@xxxxxxxxxx>
Message-ID: <1490458699-24484-10-git-send-email-sumit.semwal@xxxxxxxxxx>
From: Sumit Semwal <sumit.semwal@xxxxxxxxxx>
From: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
[ 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@xxxxxxxxxx>
Reviewed-by: Gavin Shan <gwshan@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sumit Semwal <sumit.semwal@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/pci/iov.c | 8 ++++++++
1 file changed, 8 insertions(+)
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -567,6 +567,7 @@ void pci_iov_update_resource(struct pci_
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_
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
Patches currently in stable-queue which might be from sumit.semwal@xxxxxxxxxx are
queue-4.4/pci-add-comments-about-rom-bar-updating.patch
queue-4.4/acpi-blacklist-make-dell-latitude-3350-ethernet-work.patch
queue-4.4/s390-zcrypt-introduce-cex6-toleration.patch
queue-4.4/block-allow-write_same-commands-with-the-sg_io-ioctl.patch
queue-4.4/pci-do-any-vf-bar-updates-before-enabling-the-bars.patch
queue-4.4/x86-hyperv-handle-unknown-nmis-on-one-cpu-when-unknown_nmi_panic.patch
queue-4.4/serial-8250_pci-detach-low-level-driver-during-pci-error-recovery.patch
queue-4.4/xen-do-not-re-use-pirq-number-cached-in-pci-device-msi-msg-data.patch
queue-4.4/pci-separate-vf-bar-updates-from-standard-bar-updates.patch
queue-4.4/pci-ignore-bar-updates-on-virtual-functions.patch
queue-4.4/pci-update-bars-using-property-bits-appropriate-for-type.patch
queue-4.4/vfio-spapr-postpone-allocation-of-userspace-version-of-tce-table.patch
queue-4.4/pci-don-t-update-vf-bars-while-vf-memory-space-is-enabled.patch
queue-4.4/igb-workaround-for-igb-i210-firmware-issue.patch
queue-4.4/pci-remove-pci_resource_bar-and-pci_iov_resource_bar.patch
queue-4.4/pci-decouple-ioresource_rom_enable-and-pci_rom_address_enable.patch
queue-4.4/acpi-blacklist-add-_rev-quirks-for-dell-precision-5520-and-3520.patch
queue-4.4/igb-add-i211-to-i210-phy-workaround.patch
queue-4.4/uvcvideo-uvc_scan_fallback-for-webcams-with-broken-chain.patch