Re: [PATCH v2 5/7] virt: geniezone: Add irqchip support for virtual interrupt injection

From: Marc Zyngier <maz@kernel.org>
To: Yi-De Wu <yi-de.wu@mediatek.com>
Cc: Yingshiuan Pan <yingshiuan.pan@mediatek.com>,
	Ze-Yu Wang <ze-yu.wang@mediatek.com>,
	Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Jonathan Corbet <corbet@lwn.net>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
	Matthias Brugger <matthias.bgg@gmail.com>,
	AngeloGioacchino Del Regno 
	<angelogioacchino.delregno@collabora.com>,
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-doc@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-arch@vger.kernel.org, linux-mediatek@lists.infradead.org,
	David Bradil <dbrazdil@google.com>,
	Trilok Soni <quic_tsoni@quicinc.com>,
	Jade Shih <jades.shih@mediatek.com>,
	Miles Chen <miles.chen@mediatek.com>,
	Ivan Tseng <ivan.tseng@mediatek.com>,
	My Chuang <my.chuang@mediatek.com>,
	Shawn Hsiao <shawn.hsiao@mediatek.com>,
	PeiLun Suei <peilun.suei@mediatek.com>,
	Liju Chen <liju-clr.chen@mediatek.com>
Subject: Re: [PATCH v2 5/7] virt: geniezone: Add irqchip support for virtual interrupt injection
Date: Fri, 28 Apr 2023 19:59:18 +0100	[thread overview]
Message-ID: <f1c8c1c1c091be87dfbc27b9178fc3e6@kernel.org> (raw)
In-Reply-To: <20230428103622.18291-6-yi-de.wu@mediatek.com>

On 2023-04-28 11:36, Yi-De Wu wrote:
> From: "Yingshiuan Pan" <yingshiuan.pan@mediatek.com>
> 
> Enable GenieZone to handle virtual interrupt injection request.
> 
> Signed-off-by: Yingshiuan Pan <yingshiuan.pan@mediatek.com>
> Signed-off-by: Yi-De Wu <yi-de.wu@mediatek.com>
> ---
>  arch/arm64/geniezone/Makefile       |  2 +-
>  arch/arm64/geniezone/gzvm_arch.c    | 24 ++++++--
>  arch/arm64/geniezone/gzvm_arch.h    | 11 ++++
>  arch/arm64/geniezone/gzvm_irqchip.c | 88 +++++++++++++++++++++++++++++
>  drivers/virt/geniezone/gzvm_vm.c    | 75 ++++++++++++++++++++++++
>  include/linux/gzvm_drv.h            |  4 ++
>  include/uapi/linux/gzvm.h           | 38 ++++++++++++-
>  7 files changed, 235 insertions(+), 7 deletions(-)
>  create mode 100644 arch/arm64/geniezone/gzvm_irqchip.c

[...]

> +++ b/arch/arm64/geniezone/gzvm_irqchip.c
> @@ -0,0 +1,88 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2023 MediaTek Inc.
> + */
> +
> +#include <linux/irqchip/arm-gic-v3.h>
> +#include <kvm/arm_vgic.h>

NAK.

There is no way you can rely on anything from KVM in
your own hypervisor code.

> +
> +#include <linux/gzvm.h>
> +#include <linux/gzvm_drv.h>
> +#include "gzvm_arch.h"
> +
> +/**
> + * gzvm_sync_vgic_state() - Check all LRs synced from gz hypervisor
> + *
> + * Traverse all LRs, see if any EOIed vint, notify_acked_irq if any.
> + * GZ does not fold/unfold everytime KVM_RUN, so we have to traverse 
> all saved
> + * LRs. It will not takes much more time comparing to fold/unfold 
> everytime
> + * GZVM_RUN, because there are only few LRs.
> + */
> +void gzvm_sync_vgic_state(struct gzvm_vcpu *vcpu)
> +{
> +}
> +
> +/* is_irq_valid() - Check the irq number and irq_type are matched */
> +static bool is_irq_valid(u32 irq, u32 irq_type)
> +{
> +	switch (irq_type) {
> +	case GZVM_IRQ_TYPE_CPU:
> +		/*  0 ~ 15: SGI */
> +		if (likely(irq <= GZVM_IRQ_CPU_FIQ))
> +			return true;
> +		break;
> +	case GZVM_IRQ_TYPE_PPI:
> +		/* 16 ~ 31: PPI */
> +		if (likely(irq >= VGIC_NR_SGIS && irq < VGIC_NR_PRIVATE_IRQS))

What happens if I redefine all these macros tomorrow? None of
this code should rely on anything that is *INTERNAL* to KVM.

         M.
-- 
Jazz is not dead. It just smells funny...