When the kernel is comiled with CONFIG_IRQ_REMAP=y but without
CONFIG_IOMMU_INTEL compilation fails since commit def054b01a8678 with an
undefined reference to device_rbtree_find(). This patch makes sure that
intel specific code is only compiled with CONFIG_IOMMU_INTEL=y.

Fixes: def054b01a8678 ("iommu/vt-d: Use device rbtree in iopf reporting path")

Signed-off-by: Bert Karwatzki <spasswolf@web.de>
---
 drivers/iommu/Kconfig         | 2 +-
 drivers/iommu/intel/Makefile  | 2 ++
 drivers/iommu/irq_remapping.c | 3 ++-
 3 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index e0796fa84227..0af39bbbe3a3 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -199,7 +199,7 @@ source "drivers/iommu/iommufd/Kconfig"
 config IRQ_REMAP
 	bool "Support for Interrupt Remapping"
 	depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI
-	select DMAR_TABLE
+	select DMAR_TABLE if INTEL_IOMMU
 	help
 	  Supports Interrupt remapping for IO-APIC and MSI devices.
 	  To use x2apic mode in the CPU's which support x2APIC enhancements or
diff --git a/drivers/iommu/intel/Makefile b/drivers/iommu/intel/Makefile
index 5dabf081a779..5402b699a122 100644
--- a/drivers/iommu/intel/Makefile
+++ b/drivers/iommu/intel/Makefile
@@ -5,5 +5,7 @@ obj-$(CONFIG_DMAR_TABLE) += trace.o cap_audit.o
 obj-$(CONFIG_DMAR_PERF) += perf.o
 obj-$(CONFIG_INTEL_IOMMU_DEBUGFS) += debugfs.o
 obj-$(CONFIG_INTEL_IOMMU_SVM) += svm.o
+ifdef CONFIG_INTEL_IOMMU
 obj-$(CONFIG_IRQ_REMAP) += irq_remapping.o
+endif
 obj-$(CONFIG_INTEL_IOMMU_PERF_EVENTS) += perfmon.o
diff --git a/drivers/iommu/irq_remapping.c b/drivers/iommu/irq_remapping.c
index 83314b9d8f38..ee59647c2050 100644
--- a/drivers/iommu/irq_remapping.c
+++ b/drivers/iommu/irq_remapping.c
@@ -99,7 +99,8 @@ int __init irq_remapping_prepare(void)
 	if (disable_irq_remap)
 		return -ENOSYS;

-	if (intel_irq_remap_ops.prepare() == 0)
+	if (IS_ENABLED(CONFIG_INTEL_IOMMU) &&
+	    intel_irq_remap_ops.prepare() == 0)
 		remap_ops = &intel_irq_remap_ops;
 	else if (IS_ENABLED(CONFIG_AMD_IOMMU) &&
 		 amd_iommu_irq_ops.prepare() == 0)
--
2.39.2

Since commit def054b01a8678 compilation fails on x86_64 without
CONFIG_IOMMU_INTEL=y with an undefined reference to device_rbtree_find()
when linking drivers/iommu/intel/dmar.o. Even though this file is intel
specific it is compile because CONFIG_IRQ_REMAP unconditionally selects
CONFIG_DMAR_TABLE. This patch fixes this by only compiling intel
specific files when CONFIG_IOMMU_INTEL=y.

Bert Karwatzki

On Thu, Mar 07, 2024 at 08:44:19PM +0100, Bert Karwatzki wrote:
> When the kernel is comiled with CONFIG_IRQ_REMAP=y but without
> CONFIG_IOMMU_INTEL compilation fails since commit def054b01a8678 with an
> undefined reference to device_rbtree_find(). This patch makes sure that
> intel specific code is only compiled with CONFIG_IOMMU_INTEL=y.
> 
> Fixes: def054b01a8678 ("iommu/vt-d: Use device rbtree in iopf reporting path")
> 
> Signed-off-by: Bert Karwatzki <spasswolf@web.de>
> ---
>  drivers/iommu/Kconfig         | 2 +-
>  drivers/iommu/intel/Makefile  | 2 ++
>  drivers/iommu/irq_remapping.c | 3 ++-
>  3 files changed, 5 insertions(+), 2 deletions(-)

Applied, thanks.

On 3/8/24 3:44 AM, Bert Karwatzki wrote:
> When the kernel is comiled with CONFIG_IRQ_REMAP=y but without
> CONFIG_IOMMU_INTEL compilation fails since commit def054b01a8678 with an
> undefined reference to device_rbtree_find(). This patch makes sure that
> intel specific code is only compiled with CONFIG_IOMMU_INTEL=y.
> 
> Fixes: def054b01a8678 ("iommu/vt-d: Use device rbtree in iopf reporting path")

I think it should fix below commit:

Fixes: 80a9b50c0b9e ("iommu/vt-d: Improve ITE fault handling if target 
device isn't present")

> 
> Signed-off-by: Bert Karwatzki<spasswolf@web.de>

For users who want a configuration with interrupt remapping and without
DMA remapping, they can achieve this by selecting
IOMMU_DEFAULT_PASSTHROUGH or using kernel command "iommu.passthrough=1".

Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>

Best regards,
baolu