Commit 5a949b38 authored Jun 10, 2019 by Kairui Song Committed by Borislav Petkov Jun 10, 2019

x86/kexec: Add the ACPI NVS region to the ident map



With the recent addition of RSDP parsing in the decompression stage,
a kexec-ed kernel now needs ACPI tables to be covered by the identity
mapping. And in commit

  6bbeb276 ("x86/kexec: Add the EFI system tables and ACPI tables to the ident map")

the ACPI tables memory region was added to the ident map.

But some machines have only an ACPI NVS memory region and the ACPI
tables are located in that region. In such case, the kexec-ed kernel
will still fail when trying to access ACPI tables if they're not mapped.

So add the NVS memory region to the ident map as well.

 [ bp: Massage. ]

Fixes: 6bbeb276 ("x86/kexec: Add the EFI system tables and ACPI tables to the ident map")
Suggested-by: Junichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Kairui Song <kasong@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Junichi Nomura <j-nomura@ce.jp.nec.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Chao Fan <fanc.fnst@cn.fujitsu.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: kexec@lists.infradead.org
Cc: Lianbo Jiang <lijiang@redhat.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190610073617.19767-1-kasong@redhat.com

parent 5b51ae96

arch/x86/kernel/machine_kexec_64.c

+15 −3

Original line number	Diff line number	Diff line
		@@ -54,14 +54,26 @@ static int mem_region_callback(struct resource res, void arg)
		static int
		map_acpi_tables(struct x86_mapping_info info, pgd_t level4p)
		{
		unsigned long flags = IORESOURCE_MEM \| IORESOURCE_BUSY;
		struct init_pgtable_data data;
		unsigned long flags;
		int ret;

		data.info = info;
		data.level4p = level4p;
		flags = IORESOURCE_MEM \| IORESOURCE_BUSY;
		return walk_iomem_res_desc(IORES_DESC_ACPI_TABLES, flags, 0, -1,

		ret = walk_iomem_res_desc(IORES_DESC_ACPI_TABLES, flags, 0, -1,
		&data, mem_region_callback);
		if (ret && ret != -EINVAL)
		return ret;

		/* ACPI tables could be located in ACPI Non-volatile Storage region */
		ret = walk_iomem_res_desc(IORES_DESC_ACPI_NV_STORAGE, flags, 0, -1,
		&data, mem_region_callback);
		if (ret && ret != -EINVAL)
		return ret;

		return 0;
		}
		#else
		static int map_acpi_tables(struct x86_mapping_info info, pgd_t level4p) { return 0; }

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