arm64: efi: Force the use of SetVirtualAddressMap() on eMAG and Altra Max machines

Commit 550b33c ("arm64: efi: Force the use of SetVirtualAddressMap()
on Altra machines") identifies the Altra family via the family field in
the type#1 SMBIOS record. eMAG and Altra Max machines are similarly
affected but not detected with the strict strcmp test.

The type1_family smbios string is not an entirely reliable means of
identifying systems with this issue as OEMs can, and do, use their own
strings for these fields. However, until we have a better solution,
capture the bulk of these systems by adding strcmp matching for "eMAG"
and "Altra Max".

Fixes: 550b33c ("arm64: efi: Force the use of SetVirtualAddressMap() on Altra machines")
Cc: <[email protected]> # 6.1.x
Cc: Alexandru Elisei <[email protected]>
Signed-off-by: Darren Hart <[email protected]>
Tested-by: Justin He <[email protected]>
Signed-off-by: Ard Biesheuvel <[email protected]>

Author: dvhart

drivers/firmware/efi/libstub/arm64.c

@@ -19,10 +19,13 @@ static bool system_needs_vamap(void)
 	const u8 *type1_family = efi_get_smbios_string(1, family);
 
 	/*
-	 * Ampere Altra machines crash in SetTime() if SetVirtualAddressMap()
-	 * has not been called prior.
+	 * Ampere eMAG, Altra, and Altra Max machines crash in SetTime() if
+	 * SetVirtualAddressMap() has not been called prior.
 	 */
-	if (!type1_family || strcmp(type1_family, "Altra"))
+	if (!type1_family || (
+	    strcmp(type1_family, "eMAG") &&
+	    strcmp(type1_family, "Altra") &&
+	    strcmp(type1_family, "Altra Max")))
 		return false;
 
 	efi_warn("Working around broken SetVirtualAddressMap()\n");