Re: [PATCH v7 1/4] KVM: arm64: Introduce two cache maintenance callbacks

From: Marc Zyngier
Date: Thu Jun 17 2021 - 10:20:31 EST


On Thu, 17 Jun 2021 13:38:37 +0100,
Will Deacon <will@xxxxxxxxxx> 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@xxxxxxxxxx>
> > ---
> > 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.