Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Thu, 17 Jun 2021 15:20:26 +0100
Message-ID: <87eed0d13p.wl-maz@kernel.org>
From:   Marc Zyngier <maz@kernel.org>
To:     Will Deacon <will@kernel.org>
Cc:     Yanan Wang <wangyanan55@huawei.com>,
        Quentin Perret <qperret@google.com>,
        Alexandru Elisei <alexandru.elisei@arm.com>,
        kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org,
        kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
        Catalin Marinas <catalin.marinas@arm.com>,
        James Morse <james.morse@arm.com>,
        Julien Thierry <julien.thierry.kdev@gmail.com>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        Gavin Shan <gshan@redhat.com>, wanghaibin.wang@huawei.com,
        zhukeqian1@huawei.com, yuzenghui@huawei.com
Subject: Re: [PATCH v7 1/4] KVM: arm64: Introduce two cache maintenance callbacks
In-Reply-To: <20210617123837.GA24457@willie-the-truck>
References: <20210617105824.31752-1-wangyanan55@huawei.com>
        <20210617105824.31752-2-wangyanan55@huawei.com>
        <20210617123837.GA24457@willie-the-truck>
User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue)
 FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/27.1
 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO)
MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue")
Content-Type: text/plain; charset=US-ASCII
Precedence: bulk

On Thu, 17 Jun 2021 13:38:37 +0100,
Will Deacon <will@kernel.org> wrote:
> 
> On Thu, Jun 17, 2021 at 06:58:21PM +0800, Yanan Wang wrote:
> > To prepare for performing CMOs for guest stage-2 in the fault handlers
> > in pgtable.c, here introduce two cache maintenance callbacks in struct
> > kvm_pgtable_mm_ops. We also adjust the comment alignment for the
> > existing part but make no real content change at all.
> > 
> > Signed-off-by: Yanan Wang <wangyanan55@huawei.com>
> > ---
> >  arch/arm64/include/asm/kvm_pgtable.h | 42 +++++++++++++++++-----------
> >  1 file changed, 25 insertions(+), 17 deletions(-)
> > 
> > diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h
> > index c3674c47d48c..b6ce34aa44bb 100644
> > --- a/arch/arm64/include/asm/kvm_pgtable.h
> > +++ b/arch/arm64/include/asm/kvm_pgtable.h
> > @@ -27,23 +27,29 @@ typedef u64 kvm_pte_t;
> >  
> >  /**
> >   * struct kvm_pgtable_mm_ops - Memory management callbacks.
> > - * @zalloc_page:	Allocate a single zeroed memory page. The @arg parameter
> > - *			can be used by the walker to pass a memcache. The
> > - *			initial refcount of the page is 1.
> > - * @zalloc_pages_exact:	Allocate an exact number of zeroed memory pages. The
> > - *			@size parameter is in bytes, and is rounded-up to the
> > - *			next page boundary. The resulting allocation is
> > - *			physically contiguous.
> > - * @free_pages_exact:	Free an exact number of memory pages previously
> > - *			allocated by zalloc_pages_exact.
> > - * @get_page:		Increment the refcount on a page.
> > - * @put_page:		Decrement the refcount on a page. When the refcount
> > - *			reaches 0 the page is automatically freed.
> > - * @page_count:		Return the refcount of a page.
> > - * @phys_to_virt:	Convert a physical address into a virtual address mapped
> > - *			in the current context.
> > - * @virt_to_phys:	Convert a virtual address mapped in the current context
> > - *			into a physical address.
> > + * @zalloc_page:		Allocate a single zeroed memory page.
> > + *				The @arg parameter can be used by the walker
> > + *				to pass a memcache. The initial refcount of
> > + *				the page is 1.
> > + * @zalloc_pages_exact:		Allocate an exact number of zeroed memory pages.
> > + *				The @size parameter is in bytes, and is rounded
> > + *				up to the next page boundary. The resulting
> > + *				allocation is physically contiguous.
> > + * @free_pages_exact:		Free an exact number of memory pages previously
> > + *				allocated by zalloc_pages_exact.
> > + * @get_page:			Increment the refcount on a page.
> > + * @put_page:			Decrement the refcount on a page. When the
> > + *				refcount reaches 0 the page is automatically
> > + *				freed.
> > + * @page_count:			Return the refcount of a page.
> > + * @phys_to_virt:		Convert a physical address into a virtual address
> > + *				mapped in the current context.
> > + * @virt_to_phys:		Convert a virtual address mapped in the current
> > + *				context into a physical address.
> > + * @clean_invalidate_dcache:	Clean and invalidate the data cache for the
> > + *				specified memory address range.
> 
> This should probably be explicit about whether this to the PoU/PoC/PoP.

Indeed. I can fix that locally if there is nothing else that requires
adjusting.

	M.

-- 
Without deviation from the norm, progress is not possible.