From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Fri, 9 Jan 2026 10:54:02 +0000 (+0100)
Subject: 5.15-stable patches
X-Git-Tag: v6.1.160~9
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b7881eb97b93ec6f1f556817aece9c7fa6ffabd5;p=thirdparty%2Fkernel%2Fstable-queue.git

5.15-stable patches

added patches:
	revert-iommu-amd-skip-enabling-command-event-buffers-for-kdump.patch
---

diff --git a/queue-5.15/revert-iommu-amd-skip-enabling-command-event-buffers-for-kdump.patch b/queue-5.15/revert-iommu-amd-skip-enabling-command-event-buffers-for-kdump.patch
new file mode 100644
index 0000000000..1e690e9b45
--- /dev/null
+++ b/queue-5.15/revert-iommu-amd-skip-enabling-command-event-buffers-for-kdump.patch
@@ -0,0 +1,68 @@
+From 5ecef76682ef506bae706f8122f056fe723d9c7c Mon Sep 17 00:00:00 2001
+From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+Date: Fri, 9 Jan 2026 11:48:34 +0100
+Subject: Revert "iommu/amd: Skip enabling command/event buffers for kdump"
+
+From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+This reverts commit bb8f9de71c9bd442ec5e1d52ce830428860892f0 which is
+commit 9be15fbfc6c5c89c22cf6e209f66ea43ee0e58bb upstream.
+
+This causes problems in older kernel trees as SNP host kdump is not
+supported in them, so drop it from the stable branches.
+
+Reported-by: Ashish Kalra <ashish.kalra@amd.com>
+Link: https://lore.kernel.org/r/dacdff7f-0606-4ed5-b056-2de564404d51@amd.com
+Cc: Vasant Hegde <vasant.hegde@amd.com>
+Cc: Sairaj Kodilkar <sarunkod@amd.com>
+Cc: Joerg Roedel <joerg.roedel@amd.com>
+Cc: Sasha Levin <sashal@kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/iommu/amd/init.c |   28 +++++++++-------------------
+ 1 file changed, 9 insertions(+), 19 deletions(-)
+
+--- a/drivers/iommu/amd/init.c
++++ b/drivers/iommu/amd/init.c
+@@ -696,16 +696,11 @@ static void iommu_enable_command_buffer(
+ 
+ 	BUG_ON(iommu->cmd_buf == NULL);
+ 
+-	if (!is_kdump_kernel()) {
+-		/*
+-		 * Command buffer is re-used for kdump kernel and setting
+-		 * of MMIO register is not required.
+-		 */
+-		entry = iommu_virt_to_phys(iommu->cmd_buf);
+-		entry |= MMIO_CMD_SIZE_512;
+-		memcpy_toio(iommu->mmio_base + MMIO_CMD_BUF_OFFSET,
+-			    &entry, sizeof(entry));
+-	}
++	entry = iommu_virt_to_phys(iommu->cmd_buf);
++	entry |= MMIO_CMD_SIZE_512;
++
++	memcpy_toio(iommu->mmio_base + MMIO_CMD_BUF_OFFSET,
++		    &entry, sizeof(entry));
+ 
+ 	amd_iommu_reset_cmd_buffer(iommu);
+ }
+@@ -754,15 +749,10 @@ static void iommu_enable_event_buffer(st
+ 
+ 	BUG_ON(iommu->evt_buf == NULL);
+ 
+-	if (!is_kdump_kernel()) {
+-		/*
+-		 * Event buffer is re-used for kdump kernel and setting
+-		 * of MMIO register is not required.
+-		 */
+-		entry = iommu_virt_to_phys(iommu->evt_buf) | EVT_LEN_MASK;
+-		memcpy_toio(iommu->mmio_base + MMIO_EVT_BUF_OFFSET,
+-			    &entry, sizeof(entry));
+-	}
++	entry = iommu_virt_to_phys(iommu->evt_buf) | EVT_LEN_MASK;
++
++	memcpy_toio(iommu->mmio_base + MMIO_EVT_BUF_OFFSET,
++		    &entry, sizeof(entry));
+ 
+ 	/* set head and tail to zero manually */
+ 	writel(0x00, iommu->mmio_base + MMIO_EVT_HEAD_OFFSET);
diff --git a/queue-5.15/series b/queue-5.15/series
index c7157ef626..0d8ce20310 100644
--- a/queue-5.15/series
+++ b/queue-5.15/series
@@ -498,3 +498,4 @@ ext4-filesystems-without-casefold-feature-cannot-be-mounted-with-siphash.patch
 ext4-factor-out-ext4_hash_info_init.patch
 ext4-fix-error-message-when-rejecting-the-default-hash.patch
 firmware-arm_scmi-fix-unused-notifier-block-in-unregister.patch
+revert-iommu-amd-skip-enabling-command-event-buffers-for-kdump.patch