On Sat, 28 Dec 2024 at 11:48, Phil Dennis-Jordan <p...@philjordan.eu> wrote:
> > > On Fri, 27 Dec 2024 at 21:24, Philippe Mathieu-Daudé <phi...@linaro.org> > wrote: > >> When the KVM accelerator is selected, the Kconfig ARM_GIC key >> selects the KVM GIC implementation (ARM_GIC_KVM). >> For other accelerators (TCG, HVF, ...), select the generic >> implementation. >> >> Signed-off-by: Philippe Mathieu-Daudé <phi...@linaro.org> >> --- >> hw/intc/Kconfig | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/hw/intc/Kconfig b/hw/intc/Kconfig >> index 7547528f2c2..762139d8df3 100644 >> --- a/hw/intc/Kconfig >> +++ b/hw/intc/Kconfig >> @@ -23,7 +23,7 @@ config APIC >> >> config ARM_GIC >> bool >> - select ARM_GICV3 if TCG >> + select ARM_GICV3 if !KVM >> > > Wouldn't this disable the ARM_GICV3 by default when building with > --enable-tcg --enable-kvm? And then there would be no GIC available when > running the built QEMU in TCG mode. (Bear with me, I'm a relative Meson > newbie.) > > OK, I've managed to answer my own question now by setting up a RPi5 with aarch64 RPOS and building QEMU on that with --enable-kvm --enable-tcg. With patch 1/2 applied on current upstream master, I get: $ build/qemu-system-aarch64 -accel tcg -M virt,gic-version=3 -smp 4 -m 4G *[runs successfully]* with 2/2 applied as well: $ build/qemu-system-aarch64 -accel tcg -M virt,gic-version=3 -smp 4 -m 4G qemu-system-aarch64: tcg does not support GICv3 emulation $ In other words, with the proposed change, ARM_GICV3 is indeed deselected if KVM is selected even if TCG is also selected. Possibly very basic question: is there any support for kernel-irqchip=off on aarch64/KVM? If yes, don't we need ARM_GICV3 in that case anyway, so we should drop any accel dependency on it in the first place? If we definitely don't need the software GIC in KVM-only builds, I guess we're down to listing each accel that needs it individually. Is that: select ARM_GICV3 if TCG || HVF || NVMM || WHPX || XEN_EMU || XEN or can we drop any of those? Have I missed anything? What about QTest?
