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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCHv4 07/14] xen: mark grant mapped pages as foreign
On Mon, 26 Jan 2015, David Vrabel wrote:
> From: Jennifer Herbert <jennifer.herbert@xxxxxxxxxx>
>
> Use the "foreign" page flag to mark pages that have a grant map. Use
> page->private to store information of the grant (the granting domain
> and the grant reference).
>
> Signed-off-by: Jennifer Herbert <jennifer.herbert@xxxxxxxxxx>
> Signed-off-by: David Vrabel <david.vrabel@xxxxxxxxxx>
Reviewed-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
> arch/x86/xen/p2m.c | 7 -------
> drivers/xen/grant-table.c | 43 +++++++++++++++++++++++++++++++++++++++++--
> include/xen/grant_table.h | 20 ++++++++++++++++++++
> 3 files changed, 61 insertions(+), 9 deletions(-)
>
> diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
> index a8691cb..f18fd1d 100644
> --- a/arch/x86/xen/p2m.c
> +++ b/arch/x86/xen/p2m.c
> @@ -681,12 +681,8 @@ int set_foreign_p2m_mapping(struct gnttab_map_grant_ref
> *map_ops,
> }
> pfn = page_to_pfn(pages[i]);
>
> - WARN_ON(PagePrivate(pages[i]));
> WARN(pfn_to_mfn(pfn) != INVALID_P2M_ENTRY, "page must be
> ballooned");
>
> - SetPagePrivate(pages[i]);
> - set_page_private(pages[i], mfn);
> -
> if (unlikely(!set_phys_to_machine(pfn, FOREIGN_FRAME(mfn)))) {
> ret = -ENOMEM;
> goto out;
> @@ -716,9 +712,6 @@ int clear_foreign_p2m_mapping(struct
> gnttab_unmap_grant_ref *unmap_ops,
> goto out;
> }
>
> - set_page_private(pages[i], INVALID_P2M_ENTRY);
> - WARN_ON(!PagePrivate(pages[i]));
> - ClearPagePrivate(pages[i]);
> set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
> }
> if (kunmap_ops)
> diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
> index b4f93c4..89dcca4 100644
> --- a/drivers/xen/grant-table.c
> +++ b/drivers/xen/grant-table.c
> @@ -679,12 +679,27 @@ EXPORT_SYMBOL_GPL(gnttab_free_auto_xlat_frames);
> */
> int gnttab_alloc_pages(int nr_pages, struct page **pages)
> {
> + int i;
> int ret;
>
> ret = alloc_xenballooned_pages(nr_pages, pages, false);
> if (ret < 0)
> return ret;
>
> + for (i = 0; i < nr_pages; i++) {
> +#if BITS_PER_LONG < 64
> + struct xen_page_foreign *foreign;
> +
> + foreign = kzalloc(sizeof(*foreign), GFP_KERNEL);
> + if (!foreign) {
> + gnttab_free_pages(nr_pages, pages);
> + return -ENOMEM;
> + }
> + set_page_private(pages[i], (unsigned long)foreign);
> +#endif
> + SetPagePrivate(pages[i]);
> + }
> +
> return 0;
> }
> EXPORT_SYMBOL(gnttab_alloc_pages);
> @@ -696,6 +711,16 @@ EXPORT_SYMBOL(gnttab_alloc_pages);
> */
> void gnttab_free_pages(int nr_pages, struct page **pages)
> {
> + int i;
> +
> + for (i = 0; i < nr_pages; i++) {
> + if (PagePrivate(pages[i])) {
> +#if BITS_PER_LONG < 64
> + kfree((void *)page_private(pages[i]));
> +#endif
> + ClearPagePrivate(pages[i]);
> + }
> + }
> free_xenballooned_pages(nr_pages, pages);
> }
> EXPORT_SYMBOL(gnttab_free_pages);
> @@ -756,12 +781,22 @@ int gnttab_map_refs(struct gnttab_map_grant_ref
> *map_ops,
> if (ret)
> return ret;
>
> - /* Retry eagain maps */
> - for (i = 0; i < count; i++)
> + for (i = 0; i < count; i++) {
> + /* Retry eagain maps */
> if (map_ops[i].status == GNTST_eagain)
> gnttab_retry_eagain_gop(GNTTABOP_map_grant_ref, map_ops
> + i,
> &map_ops[i].status, __func__);
>
> + if (map_ops[i].status == GNTST_okay) {
> + struct xen_page_foreign *foreign;
> +
> + SetPageForeign(pages[i]);
> + foreign = xen_page_foreign(pages[i]);
> + foreign->domid = map_ops[i].dom;
> + foreign->gref = map_ops[i].ref;
> + }
> + }
> +
> return set_foreign_p2m_mapping(map_ops, kmap_ops, pages, count);
> }
> EXPORT_SYMBOL_GPL(gnttab_map_refs);
> @@ -770,12 +805,16 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref
> *unmap_ops,
> struct gnttab_unmap_grant_ref *kunmap_ops,
> struct page **pages, unsigned int count)
> {
> + unsigned int i;
> int ret;
>
> ret = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap_ops,
> count);
> if (ret)
> return ret;
>
> + for (i = 0; i < count; i++)
> + ClearPageForeign(pages[i]);
> +
> return clear_foreign_p2m_mapping(unmap_ops, kunmap_ops, pages, count);
> }
> EXPORT_SYMBOL_GPL(gnttab_unmap_refs);
> diff --git a/include/xen/grant_table.h b/include/xen/grant_table.h
> index 949803e..d3bef56 100644
> --- a/include/xen/grant_table.h
> +++ b/include/xen/grant_table.h
> @@ -45,6 +45,8 @@
> #include <asm/xen/hypervisor.h>
>
> #include <xen/features.h>
> +#include <linux/mm_types.h>
> +#include <linux/page-flags.h>
>
> #define GNTTAB_RESERVED_XENSTORE 1
>
> @@ -185,4 +187,22 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref
> *unmap_ops,
> void gnttab_batch_map(struct gnttab_map_grant_ref *batch, unsigned count);
> void gnttab_batch_copy(struct gnttab_copy *batch, unsigned count);
>
> +
> +struct xen_page_foreign {
> + domid_t domid;
> + grant_ref_t gref;
> +};
> +
> +static inline struct xen_page_foreign *xen_page_foreign(struct page *page)
> +{
> + if (!PageForeign(page))
> + return NULL;
> +#if BITS_PER_LONG < 64
> + return (struct xen_page_foreign *)page->private;
> +#else
> + BUILD_BUG_ON(sizeof(struct xen_page_foreign) > BITS_PER_LONG);
> + return (struct xen_page_foreign *)&page->private;
> +#endif
> +}
> +
> #endif /* __ASM_GNTTAB_H__ */
> --
> 1.7.10.4
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxx
> http://lists.xen.org/xen-devel
>
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