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author | Jennifer Herbert <jennifer.herbert@citrix.com> | 2014-12-24 14:17:06 (GMT) |
---|---|---|
committer | David Vrabel <david.vrabel@citrix.com> | 2015-01-28 14:03:12 (GMT) |
commit | 8da7633f168b5428e2cfb7342408b2c44088f5df (patch) | |
tree | 33e17f065d1aa9bf8a57ac03b737154bac0d3468 | |
parent | ff4b156f166b3931894d2a8b5cdba6cdf4da0618 (diff) | |
download | linux-8da7633f168b5428e2cfb7342408b2c44088f5df.tar.xz |
xen: mark grant mapped pages as foreign
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@citrix.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
-rw-r--r-- | arch/x86/xen/p2m.c | 7 | ||||
-rw-r--r-- | drivers/xen/grant-table.c | 43 | ||||
-rw-r--r-- | 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__ */ |