[PATCHv7 11/14] x86: Disable kexec if system has unaccepted memory

Kirill A. Shutemov
2022-06-14T12:02:44Z

On kexec, the target kernel has to know what memory has been accepted.
Information in EFI map is out of date and cannot be used.

boot_params.unaccepted_memory can be used to pass the bitmap between two
kernels on kexec, but the use-case is not yet implemented.

Disable kexec on machines with unaccepted memory for now.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
arch/x86/mm/unaccepted_memory.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)

diff --git a/arch/x86/mm/unaccepted_memory.c b/arch/x86/mm/unaccepted_memory.c
index bcd56fe82b9e..05e216716690 100644
--- a/arch/x86/mm/unaccepted_memory.c
+++ b/arch/x86/mm/unaccepted_memory.c
@@ -1,4 +1,5 @@
// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/kexec.h>
#include <linux/memblock.h>
#include <linux/mm.h>
#include <linux/pfn.h>
@@ -95,3 +96,21 @@ bool range_contains_unaccepted_memory(phys_addr_t start, phys_addr_t end)

return ret;
}
+
+static int __init unaccepted_init(void)
+{
+ if (!boot_params.unaccepted_memory)
+ return 0;
+
+#ifdef CONFIG_KEXEC_CORE
+ /*
+ * TODO: Information on memory acceptance status has to be communicated
+ * between kernel.
+ */
+ pr_warn("Disable kexec: not yet supported on systems with unaccepted memory\n");
+ kexec_load_disabled = 1;
+#endif
+
+ return 0;
+}
+fs_initcall(unaccepted_init);
--
2.35.1