The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 0288c3e709e5fabd51e84715c5c798a02f43061a # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2023102020-spyglass-frostlike-54b5@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 0288c3e709e5fabd51e84715c5c798a02f43061a Mon Sep 17 00:00:00 2001 From: Jesse Brandeburg jesse.brandeburg@intel.com Date: Wed, 11 Oct 2023 16:33:33 -0700 Subject: [PATCH] ice: reset first in crash dump kernels

When the system boots into the crash dump kernel after a panic, the ice networking device may still have pending transactions that can cause errors or machine checks when the device is re-enabled. This can prevent the crash dump kernel from loading the driver or collecting the crash data.

To avoid this issue, perform a function level reset (FLR) on the ice device via PCIe config space before enabling it on the crash kernel. This will clear any outstanding transactions and stop all queues and interrupts. Restore the config space after the FLR, otherwise it was found in testing that the driver wouldn't load successfully.

The following sequence causes the original issue: - Load the ice driver with modprobe ice - Enable SR-IOV with 2 VFs: echo 2 > /sys/class/net/eth0/device/sriov_num_vfs - Trigger a crash with echo c > /proc/sysrq-trigger - Load the ice driver again (or let it load automatically) with modprobe ice - The system crashes again during pcim_enable_device()

Fixes: 837f08fdecbe ("ice: Add basic driver framework for Intel(R) E800 Series") Reported-by: Vishal Agrawal vagrawal@redhat.com Reviewed-by: Jay Vosburgh jay.vosburgh@canonical.com Reviewed-by: Przemek Kitszel przemyslaw.kitszel@intel.com Signed-off-by: Jesse Brandeburg jesse.brandeburg@intel.com Tested-by: Pucha Himasekhar Reddy himasekharx.reddy.pucha@intel.com (A Contingent worker at Intel) Link: https://lore.kernel.org/r/20231011233334.336092-3-jacob.e.keller@intel.com Signed-off-by: Jakub Kicinski kuba@kernel.org

diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c index c8286adae946..6550c46e4e36 100644 --- a/drivers/net/ethernet/intel/ice/ice_main.c +++ b/drivers/net/ethernet/intel/ice/ice_main.c @@ -6,6 +6,7 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <generated/utsrelease.h> +#include <linux/crash_dump.h> #include "ice.h" #include "ice_base.h" #include "ice_lib.h" @@ -5014,6 +5015,20 @@ ice_probe(struct pci_dev *pdev, const struct pci_device_id __always_unused *ent) return -EINVAL; }

+ /* when under a kdump kernel initiate a reset before enabling the + * device in order to clear out any pending DMA transactions. These + * transactions can cause some systems to machine check when doing + * the pcim_enable_device() below. + */ + if (is_kdump_kernel()) { + pci_save_state(pdev); + pci_clear_master(pdev); + err = pcie_flr(pdev); + if (err) + return err; + pci_restore_state(pdev); + } + /* this driver uses devres, see * Documentation/driver-api/driver-model/devres.rst */