From f6768aa1b4c6a80448eabd22bb9b4123c709caea Mon Sep 17 00:00:00 2001 From: Remi Denis-Courmont Date: Sat, 26 Jan 2019 08:52:10 +0200 Subject: [PATCH] target/arm: fix AArch64 virtual address space size Since QEMU does not support the ARMv8.2-LVA, Large Virtual Address, extension (yet), the VA address space is 48-bits plus a sign bit. User mode can only handle the positive half of the address space, so that makes a limit of 48 bits. (With LVA, it would be 53 and 52 bits respectively.) The incorrectly large address space conflicts with PAuth instructions, which use bits 48-54 and 56-63 for the pointer authentication code. This also conflicts with (as yet unsupported by QEMU) data tagging and with the ARMv8.5-MTE extension. Signed-off-by: Remi Denis-Courmont Reviewed-by: Richard Henderson Signed-off-by: Peter Maydell --- target/arm/cpu.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/target/arm/cpu.h b/target/arm/cpu.h index 63934a200a..a68bcc9fed 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -2512,7 +2512,7 @@ bool write_cpustate_to_list(ARMCPU *cpu); #if defined(TARGET_AARCH64) # define TARGET_PHYS_ADDR_SPACE_BITS 48 -# define TARGET_VIRT_ADDR_SPACE_BITS 64 +# define TARGET_VIRT_ADDR_SPACE_BITS 48 #else # define TARGET_PHYS_ADDR_SPACE_BITS 40 # define TARGET_VIRT_ADDR_SPACE_BITS 32