Differential D19591 Diff 55098 sysutils/xen-tools/files/0001-xen-mapcache-use-MAP_FIXED-flag-so-the-mmap-address-qemuu.patch
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sysutils/xen-tools/files/0001-xen-mapcache-use-MAP_FIXED-flag-so-the-mmap-address-qemuu.patch
- This file was added.
| From f3069a581c0f96b62c59b06a43b57561f7418813 Mon Sep 17 00:00:00 2001 | |||||
| From: Roger Pau Monne <roger.pau@citrix.com> | |||||
| Date: Fri, 15 Mar 2019 09:27:19 +0100 | |||||
| Subject: [PATCH] xen-mapcache: use MAP_FIXED flag so the mmap address hint is | |||||
| always honored | |||||
| MIME-Version: 1.0 | |||||
| Content-Type: text/plain; charset=UTF-8 | |||||
| Content-Transfer-Encoding: 8bit | |||||
| Or if it's not possible to honor the hinted address an error is returned | |||||
| instead. This makes it easier to spot the actual failure, instead of | |||||
| failing later on when the caller of xen_remap_bucket realizes the | |||||
| mapping has not been created at the requested address. | |||||
| Also note that at least on FreeBSD using MAP_FIXED will cause mmap to | |||||
| try harder to honor the passed address. | |||||
| Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> | |||||
| --- | |||||
| Cc: Stefano Stabellini <sstabellini@kernel.org> | |||||
| Cc: Anthony Perard <anthony.perard@citrix.com> | |||||
| Cc: Paul Durrant <paul.durrant@citrix.com> | |||||
| Cc: Igor Druzhinin <igor.druzhinin@citrix.com> | |||||
| Cc: Paolo Bonzini <pbonzini@redhat.com> | |||||
| Cc: Richard Henderson <rth@twiddle.net> | |||||
| Cc: Eduardo Habkost <ehabkost@redhat.com> | |||||
| Cc: "Michael S. Tsirkin" <mst@redhat.com> | |||||
| Cc: Marcel Apfelbaum <marcel.apfelbaum@gmail.com> | |||||
| Cc: xen-devel@lists.xenproject.org | |||||
| --- | |||||
| hw/i386/xen/xen-mapcache.c | 8 +++++++- | |||||
| 1 file changed, 7 insertions(+), 1 deletion(-) | |||||
| diff --git a/hw/i386/xen/xen-mapcache.c b/hw/i386/xen/xen-mapcache.c | |||||
| index 349f72d00c..0e2870b320 100644 | |||||
| --- a/hw/i386/xen/xen-mapcache.c | |||||
| +++ b/hw/i386/xen/xen-mapcache.c | |||||
| @@ -185,8 +185,14 @@ static void xen_remap_bucket(MapCacheEntry *entry, | |||||
| } | |||||
| if (!dummy) { | |||||
| + /* | |||||
| + * If the caller has requested the mapping at a specific address use | |||||
| + * MAP_FIXED to make sure it's honored. Note that with MAP_FIXED at | |||||
| + * least FreeBSD will try harder to honor the passed address. | |||||
| + */ | |||||
| vaddr_base = xenforeignmemory_map2(xen_fmem, xen_domid, vaddr, | |||||
| - PROT_READ | PROT_WRITE, 0, | |||||
| + PROT_READ | PROT_WRITE, | |||||
| + vaddr ? MAP_FIXED : 0, | |||||
| nb_pfn, pfns, err); | |||||
| if (vaddr_base == NULL) { | |||||
| perror("xenforeignmemory_map2"); | |||||
| -- | |||||
| 2.17.2 (Apple Git-113) | |||||