x86/amd_node: Fix PCI device reference counting in amd_smn_init()grafted

The local "root" pointer is a temporary variable used during the device
search. Therefore, refcount related to the search iterators should be cleaned
up after the search is complete.

Use the __free() cleanup macro to ensure the refcount is decremented when the
temporary pointer goes out of scope.

Additionally, increment the refcount when caching a root pointer. This ensures
the in-use refcount is separate from the temporary search refcounting.

Finally, drop the redundant "root = NULL" before the second search loop. The
pci_get_class() iterator always decrements the refcount of its "from"
argument, so the first loop can only fall through with "root" already NULL.

Fixes: 0a4b61d9c2e4 ("x86/amd_node: Fix AMD root device caching")
Closes: https://sashiko.dev/#/patchset/20260806160159.230453-1-jason.andryuk%40amd.com
Reported-by: Sashiko <sashiko-bot@kernel.org>
Assisted-by: LLM
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Cc: <stable@kernel.org>
Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com

1 files changed, 143 insertions, 0 deletions

diff --git a/arch/powerpc/kvm/Makefile b/arch/powerpc/kvm/Makefile
new file mode 100644
index 000000000..4bd9d1230
--- /dev/null
+++ b/arch/powerpc/kvm/Makefile
@@ -0,0 +1,143 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for Kernel-based Virtual Machine module
+#
+
+ccflags-y := -Ivirt/kvm -Iarch/powerpc/kvm
+
+include $(srctree)/virt/kvm/Makefile.kvm
+
+common-objs-y += powerpc.o emulate_loadstore.o
+obj-$(CONFIG_KVM_EXIT_TIMING) += timing.o
+obj-$(CONFIG_KVM_BOOK3S_HANDLER) += book3s_exports.o
+
+AFLAGS_booke_interrupts.o := -I$(objtree)/$(obj)
+
+kvm-e500-objs := \
+	$(common-objs-y) \
+	emulate.o \
+	booke.o \
+	booke_emulate.o \
+	booke_interrupts.o \
+	e500.o \
+	e500_mmu.o \
+	e500_mmu_host.o \
+	e500_emulate.o
+kvm-objs-$(CONFIG_KVM_E500V2) := $(kvm-e500-objs)
+
+kvm-e500mc-objs := \
+	$(common-objs-y) \
+	emulate.o \
+	booke.o \
+	booke_emulate.o \
+	bookehv_interrupts.o \
+	e500mc.o \
+	e500_mmu.o \
+	e500_mmu_host.o \
+	e500_emulate.o
+kvm-objs-$(CONFIG_KVM_E500MC) := $(kvm-e500mc-objs)
+
+kvm-pr-y := \
+	fpu.o \
+	emulate.o \
+	book3s_paired_singles.o \
+	book3s_pr.o \
+	book3s_pr_papr.o \
+	book3s_emulate.o \
+	book3s_interrupts.o \
+	book3s_mmu_hpte.o \
+	book3s_64_mmu_host.o \
+	book3s_64_mmu.o \
+	book3s_32_mmu.o
+
+kvm-book3s_64-builtin-objs-$(CONFIG_KVM_BOOK3S_64_HANDLER) += \
+	book3s_64_entry.o \
+	tm.o
+
+ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
+kvm-book3s_64-builtin-objs-$(CONFIG_KVM_BOOK3S_64_HANDLER) += \
+	book3s_rmhandlers.o
+endif
+
+kvm-hv-y += \
+	book3s_hv.o \
+	book3s_hv_interrupts.o \
+	book3s_64_mmu_hv.o \
+	book3s_64_mmu_radix.o \
+	book3s_hv_nested.o
+
+kvm-hv-$(CONFIG_PPC_UV) += \
+	book3s_hv_uvmem.o
+
+kvm-hv-$(CONFIG_PPC_TRANSACTIONAL_MEM) += \
+	book3s_hv_tm.o
+
+kvm-book3s_64-builtin-xics-objs-$(CONFIG_KVM_XICS) := \
+	book3s_hv_rm_xics.o
+
+kvm-book3s_64-builtin-tm-objs-$(CONFIG_PPC_TRANSACTIONAL_MEM) += \
+	book3s_hv_tm_builtin.o
+
+ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+kvm-book3s_64-builtin-objs-$(CONFIG_KVM_BOOK3S_64_HANDLER) += \
+	book3s_hv_hmi.o \
+	book3s_hv_p9_entry.o \
+	book3s_hv_rmhandlers.o \
+	book3s_hv_rm_mmu.o \
+	book3s_hv_ras.o \
+	book3s_hv_builtin.o \
+	book3s_hv_p9_perf.o \
+	book3s_hv_nestedv2.o \
+	guest-state-buffer.o \
+	$(kvm-book3s_64-builtin-tm-objs-y) \
+	$(kvm-book3s_64-builtin-xics-objs-y)
+
+obj-$(CONFIG_GUEST_STATE_BUFFER_TEST) += test-guest-state-buffer.o
+endif
+
+kvm-book3s_64-objs-$(CONFIG_KVM_XICS) += \
+	book3s_xics.o
+
+kvm-book3s_64-objs-$(CONFIG_KVM_XIVE) += book3s_xive.o book3s_xive_native.o
+kvm-book3s_64-objs-$(CONFIG_SPAPR_TCE_IOMMU) += book3s_64_vio.o
+
+kvm-book3s_64-module-objs := \
+	$(common-objs-y) \
+	book3s.o \
+	book3s_rtas.o \
+	$(kvm-book3s_64-objs-y)
+
+kvm-objs-$(CONFIG_KVM_BOOK3S_64) := $(kvm-book3s_64-module-objs)
+
+kvm-book3s_32-objs := \
+	$(common-objs-y) \
+	emulate.o \
+	fpu.o \
+	book3s_paired_singles.o \
+	book3s.o \
+	book3s_pr.o \
+	book3s_emulate.o \
+	book3s_interrupts.o \
+	book3s_mmu_hpte.o \
+	book3s_32_mmu_host.o \
+	book3s_32_mmu.o
+kvm-objs-$(CONFIG_KVM_BOOK3S_32) := $(kvm-book3s_32-objs)
+
+kvm-objs-$(CONFIG_KVM_MPIC) += mpic.o
+
+kvm-y += $(kvm-objs-m) $(kvm-objs-y)
+
+obj-$(CONFIG_KVM_E500V2) += kvm.o
+obj-$(CONFIG_KVM_E500MC) += kvm.o
+obj-$(CONFIG_KVM_BOOK3S_64) += kvm.o
+obj-$(CONFIG_KVM_BOOK3S_32) += kvm.o
+
+obj-$(CONFIG_KVM_BOOK3S_64_PR) += kvm-pr.o
+obj-$(CONFIG_KVM_BOOK3S_64_HV) += kvm-hv.o
+
+obj-y += $(kvm-book3s_64-builtin-objs-y)
+
+# KVM does a lot in real-mode, and 64-bit Book3S KASAN doesn't support that
+ifdef CONFIG_PPC_BOOK3S_64
+KASAN_SANITIZE := n
+endif