Hi Jan
> -----Original Message-----
> From: Jan Beulich <jbeul...@suse.com>
> Sent: Tuesday, June 7, 2022 3:58 PM
> To: Penny Zheng <penny.zh...@arm.com>
> Cc: Wei Chen <wei.c...@arm.com>; Andrew Cooper
> <andrew.coop...@citrix.com>; George Dunlap <george.dun...@citrix.com>;
> Julien Grall <jul...@xen.org>; Stefano Stabellini <sstabell...@kernel.org>;
> Wei
> Liu <w...@xen.org>; xen-devel@lists.xenproject.org
> Subject: Re: [PATCH v6 9/9] xen: retrieve reserved pages on populate_physmap
>
> On 07.06.2022 09:30, Penny Zheng wrote:
> > +/*
> > + * Acquire a page from reserved page list(resv_page_list), when
> > +populating
> > + * memory for static domain on runtime.
> > + */
> > +mfn_t acquire_reserved_page(struct domain *d, unsigned int memflags)
> > +{
> > + struct page_info *page;
> > +
> > + spin_lock(&d->page_alloc_lock);
> > + /* Acquire a page from reserved page list(resv_page_list). */
> > + page = page_list_remove_head(&d->resv_page_list);
> > + spin_unlock(&d->page_alloc_lock);
>
> With page removal done under lock, ...
>
> > + if ( unlikely(!page) )
> > + return INVALID_MFN;
> > +
> > + if ( !prepare_staticmem_pages(page, 1, memflags) )
> > + goto fail;
> > +
> > + if ( assign_domstatic_pages(d, page, 1, memflags) )
> > + goto fail;
> > +
> > + return page_to_mfn(page);
> > +
> > + fail:
> > + page_list_add_tail(page, &d->resv_page_list);
> > + return INVALID_MFN;
>
> ... doesn't re-adding the page to the list also need to be done with the lock
> held?
True, Sorry about that.
Like I said in another thread with Julien, I'll add the missing half part
"
For freeing part, I shall get the lock at arch_free_heap_page(),
where we insert the page to the rsv_page_list, and release the lock at the end
of
the free_staticmem_page
"
>
> Jan
