FAILED: patch "[PATCH] mm/cma: accept memory of CMA areas reserved at a fixed address" failed to apply to 6.12-stable tree

FAILED: patch "[PATCH] mm/cma: accept memory of CMA areas reserved at a fixed address" failed to apply to 6.12-stable tree

[Sasha Levin]

The patch below does not apply to the 6.12-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.12.y
git checkout FETCH_HEAD
git cherry-pick -x f8f9cbc34a309a388c052706f3329d1b52985aa3
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '20261109200812-failed-6.12-f8f9cbc34a30@kernel.org' --subject-prefix 'PATCH 6.12.y' 'HEAD^..'

Thanks,
Sasha

------------------ original commit in Linus's tree ------------------

From f8f9cbc34a309a388c052706f3329d1b52985aa3 Mon Sep 17 00:00:00 2001
From: "Mike Rapoport (Microsoft)" <rppt@kernel.org>
Date: Thu, 29 Oct 2026 12:18:38 +0200
Subject: [PATCH] mm/cma: accept memory of CMA areas reserved at a fixed
 address

CMA areas allocated from memblock have their memory accepted by
memblock_alloc_range_nid(), but areas reserved at a fixed address with
memblock_reserve() are not.

If a fixed CMA area is requested by the cma=<size>@<base> command line
parameter, it may be in regular RAM and on TDX and SEV-SNP guests it
must be accepted.

Accept the memory of fixed CMA areas as well, so that all CMA areas are
accepted regardless of how they were reserved.

Link: https://lore.kernel.org/20261029-cma-multi-v1-2-2cbced8b5cb7@kernel.org
Fixes: 75d090fd167a ("x86/tdx: Add unaccepted memory support")
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Kiryl Shutsemau (Meta) <kas@kernel.org>
Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com>
Tested-by: Pankaj Gupta <pankaj.gupta@amd.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: <stable@vger.kernel.org>
---
 mm/cma.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/mm/cma.c b/mm/cma.c
index 0035efb1130a5..f61d52796f4ef 100644
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -381,6 +381,8 @@ static int __init cma_fixed_reserve(phys_addr_t base, phys_addr_t size)
 		return -EBUSY;
 	}
 
+	accept_memory(base, size);
+
 	return 0;
 }
 
-- 
2.53.0

[PATCH 6.12.y] mm/cma: accept memory of CMA areas reserved at a fixed address

[Sasha Levin]

From: "Mike Rapoport (Microsoft)" <rppt@kernel.org>

[ Upstream commit f8f9cbc34a309a388c052706f3329d1b52985aa3 ]

CMA areas allocated from memblock have their memory accepted by
memblock_alloc_range_nid(), but areas reserved at a fixed address with
memblock_reserve() are not.

If a fixed CMA area is requested by the cma=<size>@<base> command line
parameter, it may be in regular RAM and on TDX and SEV-SNP guests it
must be accepted.

Accept the memory of fixed CMA areas as well, so that all CMA areas are
accepted regardless of how they were reserved.

Link: https://lore.kernel.org/20261029-cma-multi-v1-2-2cbced8b5cb7@kernel.org
Fixes: 75d090fd167a ("x86/tdx: Add unaccepted memory support")
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Kiryl Shutsemau (Meta) <kas@kernel.org>
Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com>
Tested-by: Pankaj Gupta <pankaj.gupta@amd.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: <stable@vger.kernel.org>
[ sashal: placed accept_memory() directly in cma_declare_contiguous_nid() because cma_fixed_reserve() is absent ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 mm/cma.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/mm/cma.c b/mm/cma.c
index 2d9fae9392835..4a0616bb12b77 100644
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -313,6 +313,8 @@ int __init cma_declare_contiguous_nid(phys_addr_t base,
 			ret = -EBUSY;
 			goto err;
 		}
+
+		accept_memory(base, size);
 	} else {
 		phys_addr_t addr = 0;
 
-- 
2.53.0