| Message ID | 20220221102218.33785-13-julien@xen.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | xen/arm: mm: Remove open-coding mappings | expand |
On Mon, 21 Feb 2022, Julien Grall wrote: > From: Julien Grall <julien.grall@arm.com> > > At the moment, page-table can only be allocated from domheap. This means > it is not possible to create mapping in the page-tables via > map_pages_to_xen() if page-table needs to be allocated. > > In order to avoid open-coding page-tables update in early boot, we need > to be able to allocate page-tables much earlier. Thankfully, we have the > boot allocator for those cases. > > create_xen_table() is updated to cater early boot allocation by using > alloc_boot_pages(). > > Note, this is not sufficient to bootstrap the page-tables (i.e mapping > before any memory is actually mapped). This will be addressed > separately. > > Signed-off-by: Julien Grall <julien.grall@arm.com> > Signed-off-by: Julien Grall <jgrall@amazon.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> > --- > Changes in v2: > - New patch > --- > xen/arch/arm/mm.c | 20 ++++++++++++++------ > 1 file changed, 14 insertions(+), 6 deletions(-) > > diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c > index 58364bb6c820..f70b8cc7ce87 100644 > --- a/xen/arch/arm/mm.c > +++ b/xen/arch/arm/mm.c > @@ -1014,19 +1014,27 @@ static void xen_unmap_table(const lpae_t *table) > > static int create_xen_table(lpae_t *entry) > { > - struct page_info *pg; > + mfn_t mfn; > void *p; > lpae_t pte; > > - pg = alloc_domheap_page(NULL, 0); > - if ( pg == NULL ) > - return -ENOMEM; > + if ( system_state != SYS_STATE_early_boot ) > + { > + struct page_info *pg = alloc_domheap_page(NULL, 0); > + > + if ( pg == NULL ) > + return -ENOMEM; > + > + mfn = page_to_mfn(pg); > + } > + else > + mfn = alloc_boot_pages(1, 1); > > - p = xen_map_table(page_to_mfn(pg)); > + p = xen_map_table(mfn); > clear_page(p); > xen_unmap_table(p); > > - pte = mfn_to_xen_entry(page_to_mfn(pg), MT_NORMAL); > + pte = mfn_to_xen_entry(mfn, MT_NORMAL); > pte.pt.table = 1; > write_pte(entry, pte);
diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c index 58364bb6c820..f70b8cc7ce87 100644 --- a/xen/arch/arm/mm.c +++ b/xen/arch/arm/mm.c @@ -1014,19 +1014,27 @@ static void xen_unmap_table(const lpae_t *table) static int create_xen_table(lpae_t *entry) { - struct page_info *pg; + mfn_t mfn; void *p; lpae_t pte; - pg = alloc_domheap_page(NULL, 0); - if ( pg == NULL ) - return -ENOMEM; + if ( system_state != SYS_STATE_early_boot ) + { + struct page_info *pg = alloc_domheap_page(NULL, 0); + + if ( pg == NULL ) + return -ENOMEM; + + mfn = page_to_mfn(pg); + } + else + mfn = alloc_boot_pages(1, 1); - p = xen_map_table(page_to_mfn(pg)); + p = xen_map_table(mfn); clear_page(p); xen_unmap_table(p); - pte = mfn_to_xen_entry(page_to_mfn(pg), MT_NORMAL); + pte = mfn_to_xen_entry(mfn, MT_NORMAL); pte.pt.table = 1; write_pte(entry, pte);