From: Andrew Cooper <andrew.cooper3@citrix.com>
To: Shashank Balaji <shashank.mahadasyam@sony.com>,
Thomas Gleixner <tglx@kernel.org>, Ingo Molnar <mingo@redhat.com>,
Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
Suresh Siddha <suresh.b.siddha@intel.com>,
"K. Y. Srinivasan" <kys@microsoft.com>,
Haiyang Zhang <haiyangz@microsoft.com>,
Wei Liu <wei.liu@kernel.org>, Dexuan Cui <decui@microsoft.com>,
Long Li <longli@microsoft.com>,
Ajay Kaher <ajay.kaher@broadcom.com>,
Alexey Makhalov <alexey.makhalov@broadcom.com>,
Broadcom internal kernel review list
<bcm-kernel-feedback-list@broadcom.com>,
Jan Kiszka <jan.kiszka@siemens.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Juergen Gross <jgross@suse.com>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>,
Ingo Molnar <mingo@elte.hu>,
linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org,
virtualization@lists.linux.dev, jailhouse-dev@googlegroups.com,
kvm@vger.kernel.org, xen-devel@lists.xenproject.org,
Rahul Bukte <rahul.bukte@sony.com>,
Daniel Palmer <daniel.palmer@sony.com>,
Tim Bird <tim.bird@sony.com>
Subject: Re: [PATCH 2/3] x86/defconfig: add CONFIG_IRQ_REMAP
Date: Mon, 2 Feb 2026 11:35:38 +0000 [thread overview]
Message-ID: <a7d93306-42e5-4617-91df-23f7dd35aa1c@citrix.com> (raw)
In-Reply-To: <20260202-x2apic-fix-v1-2-71c8f488a88b@sony.com>
On 02/02/2026 9:51 am, Shashank Balaji wrote:
> Interrupt remapping is an architectural dependency of x2apic, which is already
> enabled in the defconfig.
There is no such dependency. VMs for example commonly have x2APIC and
no IOMMU, and even native system with fewer than 254 CPUs does not need
interrupt remapping for IO-APIC interrupts to function correctly.
For native systems with 255 or more CPUs you do want Interrupt Remapping
so enabling it in defconfig is a good move, but the justification needs
correcting.
~Andrew
next prev parent reply other threads:[~2026-02-02 11:35 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-02 9:51 [PATCH 0/3] x86/x2apic: Fix hang-up of defconfig kernel on resume from s2ram Shashank Balaji
2026-02-02 9:51 ` [PATCH 1/3] x86/x2apic: disable x2apic on resume if the kernel expects so Shashank Balaji
2026-02-02 15:02 ` kernel test robot
2026-02-02 22:31 ` kernel test robot
2026-02-03 0:24 ` Shashank Balaji
2026-02-03 21:08 ` Sohil Mehta
2026-02-04 9:17 ` Shashank Balaji
2026-02-04 18:53 ` Sohil Mehta
2026-02-05 6:07 ` Shashank Balaji
2026-02-05 23:18 ` Sohil Mehta
2026-02-06 3:44 ` Shashank Balaji
2026-02-06 8:57 ` Shashank Balaji
2026-02-07 0:37 ` Sohil Mehta
2026-02-02 9:51 ` [PATCH 2/3] x86/defconfig: add CONFIG_IRQ_REMAP Shashank Balaji
2026-02-02 11:35 ` Andrew Cooper [this message]
2026-02-02 11:54 ` Jan Kiszka
2026-02-02 12:12 ` Andrew Cooper
2026-02-02 13:50 ` Jan Kiszka
2026-02-02 9:51 ` [PATCH 3/3] x86/virt: rename x2apic_available to x2apic_without_ir_available Shashank Balaji
2026-02-06 0:10 ` Sohil Mehta
2026-02-06 9:23 ` Shashank Balaji
2026-02-13 7:39 ` Shashank Balaji
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