From: Remi Denis-Courmont Date: Sat, 26 Jan 2019 06:52:10 +0000 (+0200) Subject: target/arm: fix AArch64 virtual address space size X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=f6768aa1b4c6a80448eabd22bb9b4123c709caea;p=qemu.git 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 --- 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