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.

Backports commit f6768aa1b4c6a80448eabd22bb9b4123c709caea from qemu
This commit is contained in:
Remi Denis-Courmont 2019-02-03 17:52:39 -05:00 committed by Lioncash
parent 932c4e8569
commit a20bb60f06
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@ -2453,7 +2453,7 @@ bool write_cpustate_to_list(ARMCPU *cpu);
#if defined(TARGET_AARCH64) #if defined(TARGET_AARCH64)
# define TARGET_PHYS_ADDR_SPACE_BITS 48 # define TARGET_PHYS_ADDR_SPACE_BITS 48
# define TARGET_VIRT_ADDR_SPACE_BITS 64 # define TARGET_VIRT_ADDR_SPACE_BITS 48
#else #else
# define TARGET_PHYS_ADDR_SPACE_BITS 40 # define TARGET_PHYS_ADDR_SPACE_BITS 40
# define TARGET_VIRT_ADDR_SPACE_BITS 32 # define TARGET_VIRT_ADDR_SPACE_BITS 32