Add >= 6.17 AMD patches from @tycho

config.yaml

@@ -76,6 +76,10 @@ patches:
   lower: '6.16'
 - patch: 0001-9p-xen-mark-9p-transport-device-as-closing-when-remo.patch
   lower: '6.1'
+- patch: 0002-x86-amd_node-fix-integer-divide-by-zero-during-init.patch
+  lower: '6.17'
+- patch: 0003-x86-amd_node-fix-null-pointer-dereference-if-amd_smn.patch
+  lower: '6.17'
 images:
 - target: kernelsrc
   name: kernel-src

patches/0002-x86-amd_node-fix-integer-divide-by-zero-during-init.patch

@@ -0,0 +1,51 @@
+From 31d0c56ed10f08e0411a549c3398f7e3d93b899a Mon Sep 17 00:00:00 2001
+From: Steven Noonan <steven@uplinklabs.net>
+Date: Fri, 14 Nov 2025 10:34:21 -0800
+Subject: [PATCH 2/3] x86/amd_node: fix integer divide by zero during init
+
+On a Xen dom0 boot, this feature does not behave, and we end up
+calculating:
+
+    num_roots = 1
+    num_nodes = 2
+    roots_per_node = 0
+
+This causes a divide-by-zero in the modulus inside the loop.
+
+This change adds a couple of guards for invalid states where we might
+get a divide-by-zero.
+
+Signed-off-by: Steven Noonan <steven@uplinklabs.net>
+Signed-off-by: Ariadne Conill <ariadne@ariadne.space>
+CC: Yazen Ghannam <yazen.ghannam@amd.com>
+CC: x86@vger.kernel.org
+CC: stable@vger.kernel.org
+---
+ arch/x86/kernel/amd_node.c | 11 +++++++++++
+ 1 file changed, 11 insertions(+)
+
+diff --git a/arch/x86/kernel/amd_node.c b/arch/x86/kernel/amd_node.c
+index 3d0a4768d603..cdc6ba224d4a 100644
+--- a/arch/x86/kernel/amd_node.c
++++ b/arch/x86/kernel/amd_node.c
+@@ -282,6 +282,17 @@ static int __init amd_smn_init(void)
+ 		return -ENODEV;
+
+ 	num_nodes = amd_num_nodes();
++
++	if (!num_nodes)
++		return -ENODEV;
++
++	/* Possibly a virtualized environment (e.g. Xen) where we will get
++	 * roots_per_node=0 if the number of roots is fewer than number of
++	 * nodes
++	 */
++	if (num_roots < num_nodes)
++		return -ENODEV;
++
+ 	amd_roots = kcalloc(num_nodes, sizeof(*amd_roots), GFP_KERNEL);
+ 	if (!amd_roots)
+ 		return -ENOMEM;
+-- 
+2.51.2
+

patches/0003-x86-amd_node-fix-null-pointer-dereference-if-amd_smn.patch

@@ -0,0 +1,49 @@
+From 33ecda262c724d29f589bafb335c1afc4f47bdd7 Mon Sep 17 00:00:00 2001
+From: Steven Noonan <steven@uplinklabs.net>
+Date: Fri, 14 Nov 2025 11:41:48 -0800
+Subject: [PATCH 3/3] x86/amd_node: fix null pointer dereference if
+ amd_smn_init failed
+
+We should be checking the `smn_exclusive` flag before anything else,
+because that indicates whether we got through `amd_smn_init`
+successfully.
+
+Without this change, we dereference `amd_roots` even though it may not
+be allocated.
+
+Signed-off-by: Steven Noonan <steven@uplinklabs.net>
+Signed-off-by: Ariadne Conill <ariadne@ariadne.space>
+CC: Yazen Ghannam <yazen.ghannam@amd.com>
+CC: x86@vger.kernel.org
+CC: stable@vger.kernel.org
+---
+ arch/x86/kernel/amd_node.c | 6 +++---
+ 1 file changed, 3 insertions(+), 3 deletions(-)
+
+diff --git a/arch/x86/kernel/amd_node.c b/arch/x86/kernel/amd_node.c
+index cdc6ba224d4a..919932339f4a 100644
+--- a/arch/x86/kernel/amd_node.c
++++ b/arch/x86/kernel/amd_node.c
+@@ -88,6 +88,9 @@ static int __amd_smn_rw(u8 i_off, u8 d_off, u16 node, u32 address, u32 *value, b
+ 	struct pci_dev *root;
+ 	int err = -ENODEV;
+
++	if (!smn_exclusive)
++		return err;
++
+ 	if (node >= amd_num_nodes())
+ 		return err;
+
+@@ -95,9 +98,6 @@ static int __amd_smn_rw(u8 i_off, u8 d_off, u16 node, u32 address, u32 *value, b
+ 	if (!root)
+ 		return err;
+
+-	if (!smn_exclusive)
+-		return err;
+-
+ 	guard(mutex)(&smn_mutex);
+
+ 	err = pci_write_config_dword(root, i_off, address);
+-- 
+2.51.2
+