[v6] arm64: Support for running as a guest in Arm CCA

[PATCH v6 06/11] efi: arm64: Map Device with Prot Shared

Posted by Steven Price 1 month, 3 weeks ago

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.

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(-)

diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c
index 712718aed5dd..1cc64053d6b1 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_mmio_private(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;
-- 
2.34.1

Re: [PATCH v6 06/11] efi: arm64: Map Device with Prot Shared

Posted by Catalin Marinas 1 month, 2 weeks ago

On Fri, Oct 04, 2024 at 03:43:01PM +0100, Steven Price wrote:
> 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.
> 
> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
> Signed-off-by: Steven Price <steven.price@arm.com>

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>

Re: [PATCH v6 06/11] efi: arm64: Map Device with Prot Shared

Posted by Gavin Shan 1 month, 3 weeks ago

On 10/5/24 12:43 AM, Steven Price wrote:
> 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.
> 
> 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(-)
> 

Reviewed-by: Gavin Shan <gshan@redhat.com>