| Message ID | 20220330093617.3870589-5-Penny.Zheng@arm.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | populate/unpopulate memory when domain on static | expand |
On 30.03.2022 11:36, Penny Zheng wrote: > --- a/xen/common/memory.c > +++ b/xen/common/memory.c > @@ -249,6 +249,26 @@ static void populate_physmap(struct memop_args *a) > > mfn = _mfn(gpfn); > } > +#ifdef CONFIG_STATIC_MEMORY > + else if ( is_domain_on_static_allocation(d) ) > + { > + for ( j = 0; j < (1U << a->extent_order); j++ ) > + { > + page = page_list_remove_head(&d->resv_page_list); How do you guarantee the pages are contiguous, as required by a non-zero a->extent_order? Did you perhaps mean to forbid non-zero-order requests in this configuration? > + if ( unlikely(!page) ) > + { > + gdprintk(XENLOG_INFO, > + "Could not allocate guest page number %lx\n", > + gfn_x(_gfn(gpfn))); > + goto out; And earlier allocated pages are simply lost / leaked? Jan
Hi Jan > -----Original Message----- > From: Jan Beulich <jbeulich@suse.com> > Sent: Wednesday, March 30, 2022 5:59 PM > To: Penny Zheng <Penny.Zheng@arm.com> > Cc: Wei Chen <Wei.Chen@arm.com>; Henry Wang <Henry.Wang@arm.com>; > Andrew Cooper <andrew.cooper3@citrix.com>; George Dunlap > <george.dunlap@citrix.com>; Julien Grall <julien@xen.org>; Stefano Stabellini > <sstabellini@kernel.org>; Wei Liu <wl@xen.org>; xen- > devel@lists.xenproject.org > Subject: Re: [PATCH v1 4/5] xen/arm: retrieve reserved pages on > populate_physmap > > On 30.03.2022 11:36, Penny Zheng wrote: > > --- a/xen/common/memory.c > > +++ b/xen/common/memory.c > > @@ -249,6 +249,26 @@ static void populate_physmap(struct memop_args > *a) > > > > mfn = _mfn(gpfn); > > } > > +#ifdef CONFIG_STATIC_MEMORY > > + else if ( is_domain_on_static_allocation(d) ) > > + { > > + for ( j = 0; j < (1U << a->extent_order); j++ ) > > + { > > + page = page_list_remove_head(&d->resv_page_list); > > How do you guarantee the pages are contiguous, as required by a non-zero > a->extent_order? Did you perhaps mean to forbid non-zero-order requests > in this configuration?, True, true, thanks for pointing that out. I would not intend to add complex algorithm here to find contiguous pages of requested order, forbidding non-zero-order with error message shall be added here. > > > + if ( unlikely(!page) ) > > + { > > + gdprintk(XENLOG_INFO, > > + "Could not allocate guest page number %lx\n", > > + gfn_x(_gfn(gpfn))); > > + goto out; > > And earlier allocated pages are simply lost / leaked? > That was unconsidered, thanks for pointing that out. Since now we are forbidding non-zero-order requests, earlier allocated pages shall not need to be considered. > Jan
diff --git a/xen/common/memory.c b/xen/common/memory.c index 2afc3c6f10..2122ceeba7 100644 --- a/xen/common/memory.c +++ b/xen/common/memory.c @@ -249,6 +249,26 @@ static void populate_physmap(struct memop_args *a) mfn = _mfn(gpfn); } +#ifdef CONFIG_STATIC_MEMORY + else if ( is_domain_on_static_allocation(d) ) + { + for ( j = 0; j < (1U << a->extent_order); j++ ) + { + page = page_list_remove_head(&d->resv_page_list); + if ( unlikely(!page) ) + { + gdprintk(XENLOG_INFO, + "Could not allocate guest page number %lx\n", + gfn_x(_gfn(gpfn))); + goto out; + } + d->resv_pages--; + + if ( j == 0 ) + mfn = page_to_mfn(page); + } + } +#endif else { page = alloc_domheap_pages(d, a->extent_order, a->memflags);
When domain on static allocation populates memory through populate_physmap, other than allocating from heap, it shall allocate from resv_page_list to make sure that all guest RAM are still restricted in statically configured regions. Signed-off-by: Penny Zheng <penny.zheng@arm.com> --- xen/common/memory.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+)