[PATCH 03/12] arm/arm64: KVM: Formalise end of direct linear map

Steve Capper
2017-12-04T14:10:30Z

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@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 1f54e4e98c1e..e223a945c361 100644
--- a/arch/arm/include/asm/memory.h
+++ b/arch/arm/include/asm/memory.h
@@ -30,6 +30,7 @@

/* 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 d4bae7d6e0d8..2dedc775d151 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -67,6 +67,7 @@
(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 b36945d49986..4ff903409c65 100644
--- a/virt/kvm/arm/mmu.c
+++ b/virt/kvm/arm/mmu.c
@@ -1764,10 +1764,10 @@ int kvm_mmu_init(void)

kvm_info("IDMAP page: %lx\n", hyp_idmap_start);
kvm_info("HYP VA range: %lx:%lx\n",
- kern_hyp_va(PAGE_OFFSET), kern_hyp_va(~0UL));
+ kern_hyp_va(PAGE_OFFSET), kern_hyp_va(PAGE_OFFSET_END));

if (hyp_idmap_start >= kern_hyp_va(PAGE_OFFSET) &&
- hyp_idmap_start < kern_hyp_va(~0UL) &&
+ 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