vgic_v3_dispatch_sgi(9)

✨ vgic_v3_dispatch_sgi ✨

okay so bestie, welcome to the vgic_v3_dispatch_sgi page — it's a kernel API manual page (section 9), and it's literally all about handling SGI requests from VCPUs. no cap, that's the whole NAME vibe: handle SGI requests from VCPUs. 🎀

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🌸 SYNOPSIS 🌸

void vgic_v3_dispatch_sgi (struct kvm_vcpu *vcpu , u64 reg , bool
allow_group1 );

that's the whole signature, bestie — it returns void, so like, it does the thing and dips. 💅

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🦋 ARGUMENTS 🦋

• vcpu — the VCPU that's out here requesting a SGI. main character energy, honestly. 👑
• reg — the value that got written into ICC_{ASGI1,SGI0,SGI1}R by that VCPU. so like, whatever they scribbled into the sysreg, this is it. 📝
• allow_group1 — does the sysreg access allow generation of G1 SGIs? yes/no bestie, that's the whole question. 🙈

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💖 DESCRIPTION 💖

so with GICv3 (and ARE=1), CPUs trigger SGIs by writing to a system register. that write will trap in sys_regs.c and call this function — like, "hi, someone touched the sysreg, come deal with it." 😭

this ICC_SGI1R_EL1 register contains the upper three affinity levels of the target processors as well as a bitmask of 16 Aff0 CPUs. both. at once. iconic. ✨

now, the branching, because of course there's branching:

• if the interrupt routing mode bit is not set, we iterate over the Aff0 bits and signal the VCPUs matching the provided Aff{3,2,1}. one by one, cute little loop, slay. 🌈
• if this bit is set, we signal all, but not the calling VCPU. like, everybody gets an invite except the one who sent them. sorry babes. 💀

fr fr, that second case means the caller never signals itself — that's just how it is, don't come for me.

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🫶 SEE ALSO 🫶

• Kernel file ./arch/arm64/kvm/vgic/vgic-mmio-v3.c
• vgic_register_redist_iodev(9), vgic_v3_alloc_redist_region(9)

go read those too, they're lowkey required reading. 📚

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and that's the page, bestie! 🌟 this one lives at ./arch/arm64/kvm/vgic, dated October 2026, and it's vgic_v3_dispatch_sgi(9) all the way down. mwah, study safe, and remember: every single option stays, only the vibe changes 💜🧚