KVM: arm64: Set up .hyp.rodata ELF section

We will need to recognize pointers in .rodata specific to hyp, so
establish a .hyp.rodata ELF section. Merge it with the existing
.hyp.data..ro_after_init as they are treated the same at runtime.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210105180541.65031-3-dbrazdil@google.com

arch/arm64/include/asm/sections.h

@@ -11,7 +11,7 @@ extern char __alt_instructions[], __alt_instructions_end[];
 extern char __hibernate_exit_text_start[], __hibernate_exit_text_end[];
 extern char __hyp_idmap_text_start[], __hyp_idmap_text_end[];
 extern char __hyp_text_start[], __hyp_text_end[];
-extern char __hyp_data_ro_after_init_start[], __hyp_data_ro_after_init_end[];
+extern char __hyp_rodata_start[], __hyp_rodata_end[];
 extern char __idmap_text_start[], __idmap_text_end[];
 extern char __initdata_begin[], __initdata_end[];
 extern char __inittext_begin[], __inittext_end[];

arch/arm64/kernel/vmlinux.lds.S

@@ -31,10 +31,11 @@ jiffies = jiffies_64;
 	__stop___kvm_ex_table = .;
 
 #define HYPERVISOR_DATA_SECTIONS				\
-	HYP_SECTION_NAME(.data..ro_after_init) : {		\
-		__hyp_data_ro_after_init_start = .;		\
+	HYP_SECTION_NAME(.rodata) : {				\
+		__hyp_rodata_start = .;				\
 		*(HYP_SECTION_NAME(.data..ro_after_init))	\
-		__hyp_data_ro_after_init_end = .;		\
+		*(HYP_SECTION_NAME(.rodata))			\
+		__hyp_rodata_end = .;				\
 	}
 
 #define HYPERVISOR_PERCPU_SECTION				\

arch/arm64/kvm/arm.c

@@ -1749,11 +1749,10 @@ static int init_hyp_mode(void)
 		goto out_err;
 	}
 
-	err = create_hyp_mappings(kvm_ksym_ref(__hyp_data_ro_after_init_start),
-				  kvm_ksym_ref(__hyp_data_ro_after_init_end),
-				  PAGE_HYP_RO);
+	err = create_hyp_mappings(kvm_ksym_ref(__hyp_rodata_start),
+				  kvm_ksym_ref(__hyp_rodata_end), PAGE_HYP_RO);
 	if (err) {
-		kvm_err("Cannot map .hyp.data..ro_after_init section\n");
+		kvm_err("Cannot map .hyp.rodata section\n");
 		goto out_err;
 	}
 

arch/arm64/kvm/hyp/nvhe/hyp.lds.S

@@ -14,6 +14,9 @@
 SECTIONS {
 	HYP_SECTION(.idmap.text)
 	HYP_SECTION(.text)
+	HYP_SECTION(.data..ro_after_init)
+	HYP_SECTION(.rodata)
+
 	/*
 	 * .hyp..data..percpu needs to be page aligned to maintain the same
 	 * alignment for when linking into vmlinux.
@@ -22,5 +25,4 @@ SECTIONS {
 	HYP_SECTION_NAME(.data..percpu) : {
 		PERCPU_INPUT(L1_CACHE_BYTES)
 	}
-	HYP_SECTION(.data..ro_after_init)
 }