linux-kernel - [PATCH 2/5 V6] x86/ioremap: strengthen the logic in early_memremap_pgprot

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Date:   Fri, 31 Aug 2018 16:19:27 +0800
From:   Lianbo Jiang <lijiang@...hat.com>
To:     linux-kernel@...r.kernel.org
Cc:     mingo@...hat.com, tglx@...utronix.de, hpa@...or.com,
        ebiederm@...ssion.com, joro@...tes.org, thomas.lendacky@....com,
        dyoung@...hat.com, kexec@...ts.infradead.org,
        iommu@...ts.linux-foundation.org, bhe@...hat.com
Subject: [PATCH 2/5 V6] x86/ioremap: strengthen the logic in early_memremap_pgprot_adjust() to adjust encryption mask

For kdump kernel, when SME is enabled, the acpi table and dmi table will need
to be remapped without the memory encryption mask. So we have to strengthen
the logic in early_memremap_pgprot_adjust(), which makes us have an opportunity
to adjust the memory encryption mask.

Signed-off-by: Lianbo Jiang <lijiang@...hat.com>
---
 arch/x86/mm/ioremap.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index e01e6c695add..f9d9a39955f3 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -689,8 +689,15 @@ pgprot_t __init early_memremap_pgprot_adjust(resource_size_t phys_addr,
 	encrypted_prot = true;
 
 	if (sme_active()) {
+                /*
+                 * In kdump kernel, the acpi table and dmi table will need
+                 * to be remapped without the memory encryption mask. Here
+                 * we have to strengthen the logic to adjust the memory
+                 * encryption mask.
+                 */
 		if (early_memremap_is_setup_data(phys_addr, size) ||
-		    memremap_is_efi_data(phys_addr, size))
+		    memremap_is_efi_data(phys_addr, size) ||
+		    is_kdump_kernel())
 			encrypted_prot = false;
 	}
 
-- 
2.17.1