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[v7,06/11] efi: arm64: Map Device with Prot Shared

Message ID 20241017131434.40935-7-steven.price@arm.com (mailing list archive)
State New, archived
Headers show
Series arm64: Support for running as a guest in Arm CCA | expand

Commit Message

Steven Price Oct. 17, 2024, 1:14 p.m. UTC 
From: Suzuki K Poulose <suzuki.poulose@arm.com>

Device mappings need to be emulated by the VMM so must be mapped shared
with the host.

Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v4:
 * Reworked to use arm64_is_iomem_private() to decide whether the memory
   needs to be decrypted or not.
---
 arch/arm64/kernel/efi.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)
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Patch

diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c
index 712718aed5dd..1d25d8899dbf 100644
--- a/arch/arm64/kernel/efi.c
+++ b/arch/arm64/kernel/efi.c
@@ -34,8 +34,16 @@  static __init pteval_t create_mapping_protection(efi_memory_desc_t *md)
 	u64 attr = md->attribute;
 	u32 type = md->type;
 
-	if (type == EFI_MEMORY_MAPPED_IO)
-		return PROT_DEVICE_nGnRE;
+	if (type == EFI_MEMORY_MAPPED_IO) {
+		pgprot_t prot = __pgprot(PROT_DEVICE_nGnRE);
+
+		if (arm64_is_protected_mmio(md->phys_addr,
+					    md->num_pages << EFI_PAGE_SHIFT))
+			prot = pgprot_encrypted(prot);
+		else
+			prot = pgprot_decrypted(prot);
+		return pgprot_val(prot);
+	}
 
 	if (region_is_misaligned(md)) {
 		static bool __initdata code_is_misaligned;