This patchset implements the Arm FEAT_MOPS architectural feature, which is a set of instructions to implement memory copy and set operations. The new instructions come in sets of three: * SETP, SETM, SETE -- memory set * SETGP, SETGM, SETME -- memory set with MTE tag setting * CPYP, CPYM, CPYE -- memory copy In each case the copy or set is divided between the "prologue", "main" and "epilogue" instructions in an implementation-defined way; in guest code they are expected to always appear in order.
The first couple of patches here are a cleanup (already been seen on list) and a bugfix for something I noticed while testing the MTE related parts of this. There are two things in this patchset that are not currently ideal: (1) the MTE tag checking is correct, but not optimal for performance, because it reuses the existing checkN() function, which was designed to work on small memory areas and so prefers to read tag memory a byte at a time rather than in larger chunks that then need masking. I have opted to leave this as a TODO comment in the code for future improvement rather than try to address it in the initial submission. (2) we use the same approach the s390 memcopy instruction does, of checking for interrupts periodically so that a memcopy of 2GB doesn't stall the whole system. This doesn't work for icount mode, because there interrupts are all timed to number of instructions executed and the memcopy is still only a single insn regardless of how long it takes. I've not tried to tackle this because I'm not totally sure of what the right thing is, and also because it's a preexisting problem with the s390 equivalent insn anyway... I think it's OK for this to go as-is, and we can think about those problems later, but am open to other opinions on that. thanks -- PMM Aaron Lindsay (1): target/arm: Add ID_AA64ISAR2_EL1 Peter Maydell (13): target/arm: Remove unused allocation_tag_mem() argument target/arm: Don't skip MTE checks for LDRT/STRT at EL0 target/arm: Implement FEAT_MOPS enable bits target/arm: Pass unpriv bool to get_a64_user_mem_index() target/arm: Define syndrome function for MOPS exceptions target/arm: New function allocation_tag_mem_probe() target/arm: Implement MTE tag-checking functions for FEAT_MOPS target/arm: Implement the SET* instructions target/arm: Define new TB flag for ATA0 target/arm: Implement the SETG* instructions target/arm: Implement MTE tag-checking functions for FEAT_MOPS copies target/arm: Implement the CPY* instructions target/arm: Enable FEAT_MOPS for CPU 'max' docs/system/arm/emulation.rst | 1 + target/arm/cpu.h | 8 + target/arm/internals.h | 55 +++ target/arm/syndrome.h | 12 + target/arm/tcg/helper-a64.h | 8 + target/arm/tcg/translate.h | 4 +- target/arm/tcg/a64.decode | 33 ++ target/arm/helper.c | 32 +- target/arm/hvf/hvf.c | 1 + target/arm/kvm64.c | 2 + target/arm/tcg/cpu64.c | 4 + target/arm/tcg/helper-a64.c | 816 +++++++++++++++++++++++++++++++++ target/arm/tcg/hflags.c | 21 + target/arm/tcg/mte_helper.c | 280 +++++++++-- target/arm/tcg/translate-a64.c | 157 ++++++- 15 files changed, 1366 insertions(+), 68 deletions(-) -- 2.34.1
