Re: [PATCH v2 0/2] KVM: x86: Document APIC base memory hole constraint

Sean Christopherson <[email protected]> Wed, 5 Aug 2026 09:46:05 -0700
Newsgroups gmane.comp.emulators.kvm.devel,gmane.linux.documentation,gmane.linux.kernel
Message-ID <[email protected]>
On Wed, 08 Jul 2026 15:38:53 +0200, Tim Wiederhake wrote:
> When virtual APIC access acceleration is enabled on x86 (APICv on
> Intel, AVIC on AMD), vcpu creation installs a private memory slot at
> the default APIC base address (0xfee00000).  If user space maps a
> memory region covering that address, vcpu creation fails with -EEXIST.
> This is not documented and very puzzling when it happens.
> 
> This series documents two undocumented constraints:
> 
> [...]

Applied to kvm-x86 generic, thanks!

[1/2] KVM: x86: Document that KVM_CREATE_IRQCHIP must precede vcpu creation
      https://github.com/kvm-x86/linux/commit/d82d77c6430c
[2/2] KVM: x86: Document APIC base address constraint for in-kernel irqchip
      https://github.com/kvm-x86/linux/commit/99607da19b66

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https://github.com/kvm-x86/linux/tree/next