The riscv target incorrectly enabled semihosting always, whether the
user asked for it or not. Call semihosting_enabled() passing the
correct value to the is_userspace argument, which fixes this and also
handles the userspace=on argument. Because we do this at translate
time, we no longer need to check the privilege level in
riscv_cpu_do_interrupt().
Note that this is a behaviour change: we used to default to
semihosting being enabled, and now the user must pass
"-semihosting-config enable=on" if they want it.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20220822141230.3658237-8-peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
According to v-spec, mask agnostic behavior can be either kept as
undisturbed or set elements' bits to all 1s. To distinguish the
difference of mask policies, QEMU should be able to simulate the mask
agnostic behavior as "set mask elements' bits to all 1s".
There are multiple possibility for agnostic elements according to
v-spec. The main intent of this patch-set tries to add option that
can distinguish between mask policies. Setting agnostic elements to
all 1s allows QEMU to express this.
This is the first commit regarding the optional mask agnostic
behavior. Follow-up commits will add this optional behavior
for all rvv instructions.
Signed-off-by: eop Chen <eop.chen@sifive.com>
Reviewed-by: Frank Chang <frank.chang@sifive.com>
Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <165570784143.17634.35095816584573691-1@git.sr.ht>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Pass these along to translator_loop -- pc may be used instead
of tb->pc, and host_pc is currently unused. Adjust all targets
at one time.
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Tested-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The set of instructions that require decode_save_opc for
unwinding is really fairly small -- only insns that can
raise ILLEGAL_INSN at runtime. This includes CSR, anything
that uses a *new* fp rounding mode, and many privileged insns.
Since unwind info is stored as the difference from the
previous insn, storing a 0 for most insns minimizes the
size of the unwind info.
Booting a debian kernel image to the missing rootfs panic yields
- gen code size 22226819/1026886656
+ gen code size 21601907/1026886656
on 41k TranslationBlocks, a savings of 610kB or a bit less than 3%.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20220604231004.49990-4-richard.henderson@linaro.org>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
According to v-spec, tail agnostic behavior can be either kept as
undisturbed or set elements' bits to all 1s. To distinguish the
difference of tail policies, QEMU should be able to simulate the tail
agnostic behavior as "set tail elements' bits to all 1s".
There are multiple possibility for agnostic elements according to
v-spec. The main intent of this patch-set tries to add option that
can distinguish between tail policies. Setting agnostic elements to
all 1s allows QEMU to express this.
This is the first commit regarding the optional tail agnostic
behavior. Follow-up commits will add this optional behavior
for all rvv instructions.
Signed-off-by: eop Chen <eop.chen@sifive.com>
Reviewed-by: Frank Chang <frank.chang@sifive.com>
Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <165449614532.19704.7000832880482980398-5@git.sr.ht>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Currently, the [m|s]tval CSRs are set with trapping instruction encoding
only for illegal instruction traps taken at the time of instruction
decoding.
In RISC-V world, a valid instructions might also trap as illegal or
virtual instruction based to trapping bits in various CSRs (such as
mstatus.TVM or hstatus.VTVM).
We improve setting of [m|s]tval CSRs for all types of illegal and
virtual instruction traps.
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Frank Chang <frank.chang@sifive.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20220511144528.393530-4-apatel@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
To split up the decoder into multiple functions (both to support
vendor-specific opcodes in separate files and to simplify maintenance
of orthogonal extensions), this changes decode_op to iterate over a
table of decoders predicated on guard functions.
This commit only adds the new structure and the table, allowing for
the easy addition of additional decoders in the future.
Signed-off-by: Philipp Tomsich <philipp.tomsich@vrull.eu>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20220202005249.3566542-6-philipp.tomsich@vrull.eu>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
As the number of extensions is growing, copying them individiually
into the DisasContext will scale less and less... instead we populate
a pointer to the RISCVCPUConfig structure in the DisasContext.
This adds an extra indirection when checking for the availability of
an extension (compared to copying the fields into DisasContext).
While not a performance problem today, we can always (shallow) copy
the entire structure into the DisasContext (instead of putting a
pointer to it) if this is ever deemed necessary.
Signed-off-by: Philipp Tomsich <philipp.tomsich@vrull.eu>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220202005249.3566542-3-philipp.tomsich@vrull.eu>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
The stval and mtval registers can optionally contain the faulting
instruction on an illegal instruction exception. This patch adds support
for setting the stval and mtval registers.
The RISC-V spec states that "The stval register can optionally also be
used to return the faulting instruction bits on an illegal instruction
exception...". In this case we are always writing the value on an
illegal instruction.
This doesn't match all CPUs (some CPUs won't write the data), but in
QEMU let's just populate the value on illegal instructions. This won't
break any guest software, but will provide more information to guests.
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Message-id: 20211220064916.107241-4-alistair.francis@opensource.wdc.com
Get function to retrieve the 64 top bits of a register, stored in the gprh
field of the cpu state. Set function that writes the 128-bit value at once.
The access to the gprh field can not be protected at compile time to make
sure it is accessed only in the 128-bit version of the processor because we
have no way to indicate that the misa_mxl_max field is const.
The 128-bit ISA adds ldu, lq and sq. We provide support for these
instructions. Note that (a) we compute only 64-bit addresses to actually
access memory, cowardly utilizing the existing address translation mechanism
of QEMU, and (b) we assume for now little-endian memory accesses.
Signed-off-by: Frédéric Pétrot <frederic.petrot@univ-grenoble-alpes.fr>
Co-authored-by: Fabien Portas <fabien.portas@grenoble-inp.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20220106210108.138226-10-frederic.petrot@univ-grenoble-alpes.fr
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
SEW has the limitation which cannot exceed ELEN.
Widening instructions have a destination group with EEW = 2*SEW
and narrowing instructions have a source operand with EEW = 2*SEW.
Both of the instructions have the limitation of: 2*SEW <= ELEN.
Signed-off-by: Frank Chang <frank.chang@sifive.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20211210075704.23951-78-frank.chang@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
* Update and check vstart value for vector instructions.
* Add whole register move instruction helper functions as we have to
call helper function for case where vstart is not zero.
* Remove probe_pages() calls in vector load/store instructions
(except fault-only-first loads) to raise the memory access exception
at the exact processed vector element.
Signed-off-by: Frank Chang <frank.chang@sifive.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20211210075704.23951-67-frank.chang@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Zfhmin extension is a subset of Zfh extension, consisting only of data
transfer and conversion instructions.
If enabled, only the following instructions from Zfh extension are
included:
* flh, fsh, fmv.x.h, fmv.h.x, fcvt.s.h, fcvt.h.s
* If D extension is present: fcvt.d.h, fcvt.h.d
Signed-off-by: Frank Chang <frank.chang@sifive.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20211210074329.5775-8-frank.chang@sifive.com
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
