Re: [PATCH v5 0/2] RISC-V: KVM: Convert HGEI management to fully per-HART
From: Anup Patel
Date: Sun May 31 2026 - 11:13:07 EST
On Mon, May 25, 2026 at 3:19 PM Anup Patel <anup.patel@xxxxxxxxxxxxxxxx> wrote:
>
> From: "Guo Ren (Alibaba DAMO Academy)" <guoren@xxxxxxxxxx>
>
> This short series converts RISC-V KVM AIA's Hypervisor Guest External
> Interrupt (HGEI) line management from a global "one-size-fits-all"
> model to a fully per-HART (per-CPU) model. It also performs the
> corresponding changes in the IMSIC irqchip driver.
>
> The motivation is to properly support heterogeneous RISC-V SoCs
> (big.LITTLE, multi-vendor core mixes) where different HARTs may
> expose different numbers of guest interrupt files / HGEIE bits.
>
> After this series, HGEI allocation, freeing, and interrupt delivery
> are completely per-HART and there are no remaining global assumptions
> about number of guest interrupt files.
>
> Changelog:
> V5:
> - Avoid re-initializing hgctrl->lock in kvm_riscv_aia_enable()
> - Setup free_bitmap only once in kvm_riscv_aia_enable()
> - Make kvm_riscv_aia_nr_hgei so that it can be concurrently
> updated from kvm_riscv_aia_enable()
>
> V4:
> - Don't modify kvm_riscv_aia_nr_hgei in kvm_riscv_aia_enable()
> since we use kvm_riscv_aia_nr_hgei mostly for HGEI enable/disable
> checks.
> - Use GENMASK_ULL() instead of `BIT(hgctrl->nr_hgei + 1) - 1`
> - Always setup SGEI interrupt irrespective of kvm_riscv_aia_nr_hgei
>
> V3:
> - Move PATCH3 as first patch and kept the nr_guest_files in
> global config as the number of guest files across all CPUs
> - Droped original PATCH2 and squashed original PATCH4 into
> original PATCH1 which is now PATCH2.
> - Addressed comments in original PATCH1.
>
> V2:
> - Add per-HART IMSIC guest files to compute final HGEI count.
> - Add min(local->nr_guest_files, nr_guest_files);
>
> V1:
> - https://lore.kernel.org/kvm-riscv/20260421145451.1597930-1-guoren@xxxxxxxxxx/
>
> Guo Ren (Alibaba DAMO Academy) (2):
> irqchip/riscv-imsic: Add nr_guest_files in per-HART local config
> RISC-V: KVM: AIA: Make HGEI number management fully per-CPU
>
> arch/riscv/include/asm/kvm_aia.h | 2 +-
> arch/riscv/kvm/aia.c | 88 +++++++++++++++----------
> arch/riscv/kvm/aia_device.c | 4 +-
> arch/riscv/kvm/main.c | 8 +--
> drivers/irqchip/irq-riscv-imsic-state.c | 9 ++-
> include/linux/irqchip/riscv-imsic.h | 5 +-
> 6 files changed, 68 insertions(+), 48 deletions(-)
>
> --
> 2.43.0
>
Queued this series for Linux-7.2
Thanks,
Anup