[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [xen master] xen: retrieve reserved pages on populate_physmap
commit 172015009a6acc20357a2698800e13058ba1d3db Author: Penny Zheng <Penny.Zheng@xxxxxxx> AuthorDate: Tue Sep 6 15:39:19 2022 +0800 Commit: Julien Grall <jgrall@xxxxxxxxxx> CommitDate: Tue Sep 6 18:03:07 2022 +0100 xen: retrieve reserved pages on populate_physmap When a static domain populates memory through populate_physmap at runtime, it shall retrieve reserved pages from resv_page_list to make sure that domain's RAM is still restricted in statically configured memory regions. This commit also introduces a new helper acquire_reserved_page to make it work. Signed-off-by: Penny Zheng <penny.zheng@xxxxxxx> Reviewed-by: Julien Grall <jgrall@xxxxxxxxxx> --- xen/common/memory.c | 23 +++++++++++++++ xen/common/page_alloc.c | 74 +++++++++++++++++++++++++++++++++++++++---------- xen/include/xen/mm.h | 1 + 3 files changed, 84 insertions(+), 14 deletions(-) diff --git a/xen/common/memory.c b/xen/common/memory.c index bc89442ba5..ae8163a738 100644 --- a/xen/common/memory.c +++ b/xen/common/memory.c @@ -245,6 +245,29 @@ static void populate_physmap(struct memop_args *a) mfn = _mfn(gpfn); } + else if ( is_domain_using_staticmem(d) ) + { + /* + * No easy way to guarantee the retrieved pages are contiguous, + * so forbid non-zero-order requests here. + */ + if ( a->extent_order != 0 ) + { + gdprintk(XENLOG_WARNING, + "Cannot allocate static order-%u pages for %pd\n", + a->extent_order, d); + goto out; + } + + mfn = acquire_reserved_page(d, a->memflags); + if ( mfn_eq(mfn, INVALID_MFN) ) + { + gdprintk(XENLOG_WARNING, + "%pd: failed to retrieve a reserved page\n", + d); + goto out; + } + } else { page = alloc_domheap_pages(d, a->extent_order, a->memflags); diff --git a/xen/common/page_alloc.c b/xen/common/page_alloc.c index 18d34d1b69..62afb07bc6 100644 --- a/xen/common/page_alloc.c +++ b/xen/common/page_alloc.c @@ -2755,9 +2755,8 @@ void free_domstatic_page(struct page_info *page) put_domain(d); } -static bool __init prepare_staticmem_pages(struct page_info *pg, - unsigned long nr_mfns, - unsigned int memflags) +static bool prepare_staticmem_pages(struct page_info *pg, unsigned long nr_mfns, + unsigned int memflags) { bool need_tlbflush = false; uint32_t tlbflush_timestamp = 0; @@ -2838,6 +2837,25 @@ static struct page_info * __init acquire_staticmem_pages(mfn_t smfn, return pg; } +static int assign_domstatic_pages(struct domain *d, struct page_info *pg, + unsigned int nr_mfns, unsigned int memflags) +{ + if ( !d || (memflags & (MEMF_no_owner | MEMF_no_refcount)) ) + { + /* + * Respective handling omitted here because right now + * acquired static memory is only for domain's RAM. + */ + ASSERT_UNREACHABLE(); + return -EINVAL; + } + + if ( assign_pages(pg, nr_mfns, d, memflags) ) + return -EINVAL; + + return 0; +} + /* * Acquire nr_mfns contiguous pages, starting at #smfn, of static memory, * then assign them to one specific domain #d. @@ -2853,17 +2871,7 @@ int __init acquire_domstatic_pages(struct domain *d, mfn_t smfn, if ( !pg ) return -ENOENT; - if ( !d || (memflags & (MEMF_no_owner | MEMF_no_refcount)) ) - { - /* - * Respective handling omitted here because right now - * acquired static memory is only for guest RAM. - */ - ASSERT_UNREACHABLE(); - return -EINVAL; - } - - if ( assign_pages(pg, nr_mfns, d, memflags) ) + if ( assign_domstatic_pages(d, pg, nr_mfns, memflags) ) { unprepare_staticmem_pages(pg, nr_mfns, memflags & MEMF_no_scrub); return -EINVAL; @@ -2871,6 +2879,44 @@ int __init acquire_domstatic_pages(struct domain *d, mfn_t smfn, return 0; } + +/* + * 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; + + ASSERT_ALLOC_CONTEXT(); + + /* Acquire a page from reserved page list(resv_page_list). */ + spin_lock(&d->page_alloc_lock); + page = page_list_remove_head(&d->resv_page_list); + spin_unlock(&d->page_alloc_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_assign; + + return page_to_mfn(page); + + fail_assign: + /* + * The page was never accessible by the domain. So scrubbing can be + * skipped + */ + unprepare_staticmem_pages(page, 1, false); + fail: + spin_lock(&d->page_alloc_lock); + page_list_add_tail(page, &d->resv_page_list); + spin_unlock(&d->page_alloc_lock); + return INVALID_MFN; +} #endif /* diff --git a/xen/include/xen/mm.h b/xen/include/xen/mm.h index 93db3c4418..a925028ab3 100644 --- a/xen/include/xen/mm.h +++ b/xen/include/xen/mm.h @@ -198,6 +198,7 @@ struct npfec { #else #define MAX_ORDER 20 /* 2^20 contiguous pages */ #endif +mfn_t acquire_reserved_page(struct domain *d, unsigned int memflags); /* Private domain structs for DOMID_XEN, DOMID_IO, etc. */ extern struct domain *dom_xen, *dom_io; -- generated by git-patchbot for /home/xen/git/xen.git#master
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