As we're moving towards a much more dynamic way to compute our
HYP VA, let's express the mask in a slightly different way.
Instead of comparing the idmap position to the "low" VA mask,
we directly compute the mask by taking into account the idmap's
(VA_BIT-1) bit.
No functionnal change.
Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
---
arch/arm64/kvm/haslr.c | 34 ++++++++++++++--------------------
1 file changed, 14 insertions(+), 20 deletions(-)
diff --git a/arch/arm64/kvm/haslr.c b/arch/arm64/kvm/haslr.c
index 94475ea9847b..2c865d1c1344 100644
--- a/arch/arm64/kvm/haslr.c
+++ b/arch/arm64/kvm/haslr.c
@@ -21,28 +21,11 @@
#include <asm/insn.h>
#include <asm/kvm_mmu.h>
-#define HYP_PAGE_OFFSET_HIGH_MASK ((UL(1) << VA_BITS) - 1)
-#define HYP_PAGE_OFFSET_LOW_MASK ((UL(1) << (VA_BITS - 1)) - 1)
-
-static unsigned long get_hyp_va_mask(void)
-{
- phys_addr_t idmap_addr = __pa_symbol(__hyp_idmap_text_start);
- unsigned long mask = HYP_PAGE_OFFSET_HIGH_MASK;
-
- /*
- * Activate the lower HYP offset only if the idmap doesn't
- * clash with it,
- */
- if (idmap_addr > HYP_PAGE_OFFSET_LOW_MASK)
- mask = HYP_PAGE_OFFSET_HIGH_MASK;
-
- return mask;
-}
+static u64 va_mask;
u32 __init kvm_update_va_mask(struct alt_instr *alt, int index, u32 oinsn)
{
u32 rd, rn, insn;
- u64 imm;
/* We only expect a 1 instruction sequence */
BUG_ON((alt->orig_len / sizeof(insn)) != 1);
@@ -51,6 +34,18 @@ u32 __init kvm_update_va_mask(struct alt_instr *alt, int index, u32 oinsn)
if (has_vhe())
return aarch64_insn_gen_nop();
+ if (!va_mask) {
+ phys_addr_t idmap_addr = __pa_symbol(__hyp_idmap_text_start);
+ u64 region;
+
+ /* Where is my RAM region? */
+ region = idmap_addr & BIT(VA_BITS - 1);
+ region ^= BIT(VA_BITS - 1);
+
+ va_mask = BIT(VA_BITS - 1) - 1;
+ va_mask |= region;
+ }
+
rd = aarch64_insn_decode_register(AARCH64_INSN_REGTYPE_RD, oinsn);
rn = aarch64_insn_decode_register(AARCH64_INSN_REGTYPE_RN, oinsn);
@@ -61,10 +56,9 @@ u32 __init kvm_update_va_mask(struct alt_instr *alt, int index, u32 oinsn)
break;
case 0:
- imm = get_hyp_va_mask();
insn = aarch64_insn_gen_logical_immediate(AARCH64_INSN_LOGIC_AND,
AARCH64_INSN_VARIANT_64BIT,
- rn, rd, imm);
+ rn, rd, va_mask);
break;
}
--
2.14.2
