Received-SPF: pass (google.com: domain of linux-kernel+bounces-82907-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:40f1:3f00::1 as permitted sender) client-ip=2604:1380:40f1:3f00::1;
Message-ID: <f1ba53fd2a99949187ca392c6d4488d3d5aeaf88.camel@xry111.site>
Subject: Re: [PATCH v5 3/6] LoongArch: KVM: Add cpucfg area for kvm
 hypervisor
From: Xi Ruoyao <xry111@xry111.site>
To: maobibo <maobibo@loongson.cn>, Jiaxun Yang <jiaxun.yang@flygoat.com>, 
	Huacai Chen <chenhuacai@kernel.org>
Cc: Tianrui Zhao <zhaotianrui@loongson.cn>, Juergen Gross <jgross@suse.com>,
  Paolo Bonzini <pbonzini@redhat.com>, loongarch@lists.linux.dev,
 linux-kernel@vger.kernel.org,  virtualization@lists.linux.dev,
 kvm@vger.kernel.org
Date: Tue, 27 Feb 2024 17:05:59 +0800
In-Reply-To: <fc05cf09-bf53-158a-3cc9-eff6f06a220a@loongson.cn>
References: <20240222032803.2177856-1-maobibo@loongson.cn>
	 <20240222032803.2177856-4-maobibo@loongson.cn>
	 <CAAhV-H5eqXMqTYVb6cAVqOsDNcEDeP9HzaMKw69KFQeVaAYEdA@mail.gmail.com>
	 <d1a6c424-b710-74d6-29f6-e0d8e597e1fb@loongson.cn>
	 <CAAhV-H7p114hWUVrYRfKiBX3teG8sG7xmEW-Q-QT3i+xdLqDEA@mail.gmail.com>
	 <06647e4a-0027-9c9f-f3bd-cd525d37b6d8@loongson.cn>
	 <85781278-f3e9-4755-8715-3b9ff714fb20@app.fastmail.com>
	 <0d428e30-07a8-5a91-a20c-c2469adbf613@loongson.cn>
	 <09c5af9b-cc79-4cf2-84f7-276bb188754a@app.fastmail.com>
	 <fc05cf09-bf53-158a-3cc9-eff6f06a220a@loongson.cn>
Autocrypt: addr=xry111@xry111.site; prefer-encrypt=mutual;
 keydata=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
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
User-Agent: Evolution 3.50.4 
Precedence: bulk
MIME-Version: 1.0

On Tue, 2024-02-27 at 15:09 +0800, maobibo wrote:

> It is difficult to find an area unused by HW for CSR method since the=20
> small CSR ID range.

We may use IOCSR instead.  In kernel/cpu-probe.c there are already some
IOCSR reads.

> It is difficult to find an area unused by HW for CSR method since the=20
> small CSR ID range. However it is easy for cpucfg. Here I doubt whether=
=20
> you really know about LoongArch LVZ.

It's unfair to accuse the others for not knowing about LVZ considering
the lack of public documentation.

--=20
Xi Ruoyao <xry111@xry111.site>
School of Aerospace Science and Technology, Xidian University