x86/x2apic: Fix hangup of defconfig kernel on resume from s2ram

[PATCH v2 2/2] x86/defconfig: Add CONFIG_IRQ_REMAP

Posted by Shashank Balaji 1 month ago

x2apic is enabled in the defconfig, and interrupt remapping is an architectural
dependency of x2apic as per the Intel SDM:

	Routing of device interrupts to local APIC units operating in x2APIC
	mode requires use of the interrupt-remapping architecture specified in
	the Intel® Virtualization Technology for Directed I/O (Revision 1.3
	and/or later versions).

Enable CONFIG_IRQ_REMAP in defconfig so that a defconfig kernel on bare metal
actually uses x2apic.

Co-developed-by: Rahul Bukte <rahul.bukte@sony.com>
Signed-off-by: Rahul Bukte <rahul.bukte@sony.com>
Signed-off-by: Shashank Balaji <shashank.mahadasyam@sony.com>

---

Changes in v2:
- Mention the SDM (based on Andrew and Jan's discussion)
---
 arch/x86/configs/x86_64_defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/x86/configs/x86_64_defconfig b/arch/x86/configs/x86_64_defconfig
index 7d7310cdf8b0..269f7d808be4 100644
--- a/arch/x86/configs/x86_64_defconfig
+++ b/arch/x86/configs/x86_64_defconfig
@@ -230,6 +230,7 @@ CONFIG_EEEPC_LAPTOP=y
 CONFIG_AMD_IOMMU=y
 CONFIG_INTEL_IOMMU=y
 # CONFIG_INTEL_IOMMU_DEFAULT_ON is not set
+CONFIG_IRQ_REMAP=y
 CONFIG_EXT4_FS=y
 CONFIG_EXT4_FS_POSIX_ACL=y
 CONFIG_EXT4_FS_SECURITY=y

-- 
2.43.0

Re: [PATCH v2 2/2] x86/defconfig: Add CONFIG_IRQ_REMAP

Posted by Sohil Mehta 1 month ago

On 3/5/2026 9:46 PM, Shashank Balaji wrote:
> ---
>  arch/x86/configs/x86_64_defconfig | 1 +
>  1 file changed, 1 insertion(+)
> 

Reviewed-by: Sohil Mehta <sohil.mehta@intel.com>

> diff --git a/arch/x86/configs/x86_64_defconfig b/arch/x86/configs/x86_64_defconfig
> index 7d7310cdf8b0..269f7d808be4 100644
> --- a/arch/x86/configs/x86_64_defconfig
> +++ b/arch/x86/configs/x86_64_defconfig
> @@ -230,6 +230,7 @@ CONFIG_EEEPC_LAPTOP=y
>  CONFIG_AMD_IOMMU=y
>  CONFIG_INTEL_IOMMU=y
>  # CONFIG_INTEL_IOMMU_DEFAULT_ON is not set
> +CONFIG_IRQ_REMAP=y
>  CONFIG_EXT4_FS=y
>  CONFIG_EXT4_FS_POSIX_ACL=y
>  CONFIG_EXT4_FS_SECURITY=y
>

Re: [PATCH v2 2/2] x86/defconfig: Add CONFIG_IRQ_REMAP

Posted by Thomas Gleixner 1 month ago

On Fri, Mar 06 2026 at 14:46, Shashank Balaji wrote:
> x2apic is enabled in the defconfig, and interrupt remapping is an architectural
> dependency of x2apic as per the Intel SDM:
>
> 	Routing of device interrupts to local APIC units operating in x2APIC
> 	mode requires use of the interrupt-remapping architecture specified in
> 	the Intel® Virtualization Technology for Directed I/O (Revision 1.3
> 	and/or later versions).
>
> Enable CONFIG_IRQ_REMAP in defconfig so that a defconfig kernel on bare metal
> actually uses x2apic.
>
> Co-developed-by: Rahul Bukte <rahul.bukte@sony.com>
> Signed-off-by: Rahul Bukte <rahul.bukte@sony.com>
> Signed-off-by: Shashank Balaji <shashank.mahadasyam@sony.com>

Acked-by: Thomas Gleixner <tglx@kernel.org>

[tip: x86/misc] x86/64/defconfig: Add CONFIG_IRQ_REMAP

Posted by tip-bot2 for Shashank Balaji 1 month ago

The following commit has been merged into the x86/misc branch of tip:

Commit-ID:     bcf92fbca6055b7b717c3706e4e5f92a4e63ef45
Gitweb:        https://git.kernel.org/tip/bcf92fbca6055b7b717c3706e4e5f92a4e63ef45
Author:        Shashank Balaji <shashank.mahadasyam@sony.com>
AuthorDate:    Fri, 06 Mar 2026 14:46:29 +09:00
Committer:     Borislav Petkov (AMD) <bp@alien8.de>
CommitterDate: Tue, 10 Mar 2026 19:01:37 +01:00

x86/64/defconfig: Add CONFIG_IRQ_REMAP

x2apic is enabled in the defconfig, and interrupt remapping is an
architectural dependency of x2apic as per the Intel SDM:

  Routing of device interrupts to local APIC units operating in x2APIC
  mode requires use of the interrupt-remapping architecture specified in
  the Intel® Virtualization Technology for Directed I/O (Revision 1.3
  and/or later versions).

Enable CONFIG_IRQ_REMAP in defconfig so that a defconfig kernel on bare metal
actually uses x2apic.

Co-developed-by: Rahul Bukte <rahul.bukte@sony.com>
Signed-off-by: Rahul Bukte <rahul.bukte@sony.com>
Signed-off-by: Shashank Balaji <shashank.mahadasyam@sony.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Sohil Mehta <sohil.mehta@intel.com>
Acked-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20260306-x2apic-fix-v2-2-bee99c12efa3@sony.com
---
 arch/x86/configs/x86_64_defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/x86/configs/x86_64_defconfig b/arch/x86/configs/x86_64_defconfig
index 7d7310c..269f7d8 100644
--- a/arch/x86/configs/x86_64_defconfig
+++ b/arch/x86/configs/x86_64_defconfig
@@ -230,6 +230,7 @@ CONFIG_EEEPC_LAPTOP=y
 CONFIG_AMD_IOMMU=y
 CONFIG_INTEL_IOMMU=y
 # CONFIG_INTEL_IOMMU_DEFAULT_ON is not set
+CONFIG_IRQ_REMAP=y
 CONFIG_EXT4_FS=y
 CONFIG_EXT4_FS_POSIX_ACL=y
 CONFIG_EXT4_FS_SECURITY=y