[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH v2 03/16] Xen: xlate: Use page_to_xen_pfn instead of page_to_pfn
On 2016/1/19 22:59, Stefano Stabellini wrote: On Mon, 18 Jan 2016, Shannon Zhao wrote:On 2016/1/16 1:08, Stefano Stabellini wrote:On Fri, 15 Jan 2016, Shannon Zhao wrote:From: Shannon Zhao <shannon.zhao@xxxxxxxxxx> Use page_to_xen_pfn in case of 64KB page. Signed-off-by: Shannon Zhao <shannon.zhao@xxxxxxxxxx> --- drivers/xen/xlate_mmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/xen/xlate_mmu.c b/drivers/xen/xlate_mmu.c index 9692656..b9fcc2c 100644 --- a/drivers/xen/xlate_mmu.c +++ b/drivers/xen/xlate_mmu.c @@ -227,7 +227,7 @@ int __init xen_xlate_map_ballooned_pages(xen_pfn_t **gfns, void **virt, return rc; } for (i = 0; i < nr_grant_frames; i++) - pfns[i] = page_to_pfn(pages[i]); + pfns[i] = page_to_xen_pfn(pages[i]);Shannon, thanks for the patch. Keeping in mind that in the 64K case, kernel pages are 64K but xen pages are still 4K, I think you also need to allocate (nr_grant_frames/XEN_PFN_PER_PAGE) kernel pages (assuming that they are allocated contiguously): nr_grant_frames refers to 4K pages, while xen_xlate_map_ballooned_pages is allocating pages on a 64K granularity (sizeof(pages[0]) == 64K). Be careful that alloc_xenballooned_pages deals with 64K pages (because it deals with kernel pages), while xen_pfn_t is always 4K based (because it deals with Xen pfns). Please test it with and without CONFIG_ARM64_64K_PAGES. Thanks!Stefano, thanks for your explanation. How about below patch?Good work, it looks like you covered all bases, I think it should work, but I haven't tested it myself. Just one note below.diff --git a/drivers/xen/xlate_mmu.c b/drivers/xen/xlate_mmu.c index 9692656..e1f7c95 100644 --- a/drivers/xen/xlate_mmu.c +++ b/drivers/xen/xlate_mmu.c @@ -207,9 +207,12 @@ int __init xen_xlate_map_ballooned_pages(xen_pfn_t **gfns, void **virt, void *vaddr; int rc; unsigned int i; + unsigned long nr_pages; + xen_pfn_t xen_pfn = 0; BUG_ON(nr_grant_frames == 0); - pages = kcalloc(nr_grant_frames, sizeof(pages[0]), GFP_KERNEL); + nr_pages = DIV_ROUND_UP(nr_grant_frames, XEN_PFN_PER_PAGE); + pages = kcalloc(nr_pages, sizeof(pages[0]), GFP_KERNEL); if (!pages) return -ENOMEM; @@ -218,22 +221,25 @@ int __init xen_xlate_map_ballooned_pages(xen_pfn_t **gfns, void **virt, kfree(pages); return -ENOMEM; } - rc = alloc_xenballooned_pages(nr_grant_frames, pages); + rc = alloc_xenballooned_pages(nr_pages, pages); if (rc) { - pr_warn("%s Couldn't balloon alloc %ld pfns rc:%d\n", __func__, - nr_grant_frames, rc); + pr_warn("%s Couldn't balloon alloc %ld pages rc:%d\n", __func__, + nr_pages, rc); kfree(pages); kfree(pfns); return rc; } - for (i = 0; i < nr_grant_frames; i++) - pfns[i] = page_to_pfn(pages[i]); + for (i = 0; i < nr_grant_frames; i++) { + if ((i % XEN_PFN_PER_PAGE) == 0) + xen_pfn = page_to_xen_pfn(pages[i / XEN_PFN_PER_PAGE]); + pfns[i] = xen_pfn++; + }We might want to: pfns[i] = pfn_to_gfn(xen_pfn++); for consistency, even though for autotranslate guests pfn_to_gfn always returns pfn. Ok, will add. Thanks. - vaddr = vmap(pages, nr_grant_frames, 0, PAGE_KERNEL); + vaddr = vmap(pages, nr_pages, 0, PAGE_KERNEL); if (!vaddr) { - pr_warn("%s Couldn't map %ld pfns rc:%d\n", __func__, - nr_grant_frames, rc); - free_xenballooned_pages(nr_grant_frames, pages); + pr_warn("%s Couldn't map %ld pages rc:%d\n", __func__, + nr_pages, rc); + free_xenballooned_pages(nr_pages, pages); kfree(pages); kfree(pfns); return -ENOMEM; -- Shannon -- Shannon _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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