[PATCH v3 1/8] arm/arm64: KVM: Formalise end of direct linear map

[Steve Capper]

We assume that the direct linear map ends at ~0 in the KVM HYP map
intersection checking code. This assumption will become invalid later on
for arm64 when the address space of the kernel is re-arranged.

This patch introduces a new constant PAGE_OFFSET_END for both arm and
arm64 and defines it to be ~0UL

Signed-off-by: Steve Capper <steve.capper at arm.com>
---
 arch/arm/include/asm/memory.h   | 1 +
 arch/arm64/include/asm/memory.h | 1 +
 virt/kvm/arm/mmu.c              | 4 ++--
 3 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h
index ed8fd0d19a3e..45c211fd50da 100644
--- a/arch/arm/include/asm/memory.h
+++ b/arch/arm/include/asm/memory.h
@@ -24,6 +24,7 @@
 
 /* PAGE_OFFSET - the virtual address of the start of the kernel image */
 #define PAGE_OFFSET		UL(CONFIG_PAGE_OFFSET)
+#define PAGE_OFFSET_END		(~0UL)
 
 #ifdef CONFIG_MMU
 
diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index 49d99214f43c..c5617cbbf1ff 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -61,6 +61,7 @@
 	(UL(1) << VA_BITS) + 1)
 #define PAGE_OFFSET		(UL(0xffffffffffffffff) - \
 	(UL(1) << (VA_BITS - 1)) + 1)
+#define PAGE_OFFSET_END		(~0UL)
 #define KIMAGE_VADDR		(MODULES_END)
 #define MODULES_END		(MODULES_VADDR + MODULES_VSIZE)
 #define MODULES_VADDR		(VA_START + KASAN_SHADOW_SIZE)
diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c
index 7f6a944db23d..22af347d65f1 100644
--- a/virt/kvm/arm/mmu.c
+++ b/virt/kvm/arm/mmu.c
@@ -1927,10 +1927,10 @@ int kvm_mmu_init(void)
 	kvm_debug("IDMAP page: %lx\n", hyp_idmap_start);
 	kvm_debug("HYP VA range: %lx:%lx\n",
 		  kern_hyp_va(PAGE_OFFSET),
-		  kern_hyp_va((unsigned long)high_memory - 1));
+		  kern_hyp_va(PAGE_OFFSET_END));
 
 	if (hyp_idmap_start >= kern_hyp_va(PAGE_OFFSET) &&
-	    hyp_idmap_start <  kern_hyp_va((unsigned long)high_memory - 1) &&
+	    hyp_idmap_start <  kern_hyp_va(PAGE_OFFSET_END) &&
 	    hyp_idmap_start != (unsigned long)__hyp_idmap_text_start) {
 		/*
 		 * The idmap page is intersecting with the VA space,
-- 
2.11.0