elp state is recorded in *status on trap entry (less privilege to higher
privilege) and restored in elp from *status on trap exit (higher to less
privilege).
Additionally this patch introduces a forward cfi helper function to
determine if current privilege has forward cfi is enabled or not based on
*envcfg (for U, VU, S, VU, HS) or mseccfg csr (for M).
Signed-off-by: Deepak Gupta <debug@rivosinc.com>
Co-developed-by: Jim Shu <jim.shu@sifive.com>
Co-developed-by: Andy Chiu <andy.chiu@sifive.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20241008225010.1861630-5-debug@rivosinc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Both CSRRS and CSRRC always read the addressed CSR and cause any read side
effects regardless of rs1 and rd fields. Note that if rs1 specifies a register
holding a zero value other than x0, the instruction will still attempt to write
the unmodified value back to the CSR and will cause any attendant side effects.
So if CSRRS or CSRRC tries to write a read-only CSR with rs1 which specifies
a register holding a zero value, an illegal instruction exception should be
raised.
Signed-off-by: Yu-Ming Chang <yumin686@andestech.com>
Signed-off-by: Alvin Chang <alvinga@andestech.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <172100444279.18077.6893072378718059541-0@git.sr.ht>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Combining riscv_cpu_set_virt_enabled() and riscv_cpu_set_mode()
functions. This is to make complete mode change information
available through a single function.
This allows to easily differentiate between HS->VS, VS->HS
and VS->VS transitions when executing state update codes.
For example: One use-case which inspired this change is
to update mode-specific instruction and cycle counters
which requires information of both prev mode and current
mode.
Signed-off-by: Rajnesh Kanwal <rkanwal@rivosinc.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Message-ID: <20240711-smcntrpmf_v7-v8-1-b7c38ae7b263@rivosinc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Implementing wrs.nto to always just return is consistent with the
specification, as the instruction is permitted to terminate the
stall for any reason, but it's not useful for virtualization, where
we'd like the guest to trap to the hypervisor in order to allow
scheduling of the lock holding VCPU. Change to always immediately
raise exceptions when the appropriate conditions are present,
otherwise continue to just return. Note, immediately raising
exceptions is also consistent with the specification since the
time limit that should expire prior to the exception is
implementation-specific.
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Christoph Müllner <christoph.muellner@vrull.eu>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20240424142808.62936-2-ajones@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
- Trap satp/hgatp accesses from HS-mode when MSTATUS.TVM is enabled.
- Trap satp accesses from VS-mode when HSTATUS.VTVM is enabled.
- Raise RISCV_EXCP_ILLEGAL_INST when U-mode executes SFENCE.VMA/SINVAL.VMA.
- Raise RISCV_EXCP_VIRT_INSTRUCTION_FAULT when VU-mode executes
SFENCE.VMA/SINVAL.VMA or VS-mode executes SFENCE.VMA/SINVAL.VMA with
HSTATUS.VTVM enabled.
- Raise RISCV_EXCP_VIRT_INSTRUCTION_FAULT when VU-mode executes
HFENCE.GVMA/HFENCE.VVMA/HINVAL.GVMA/HINVAL.VVMA.
Signed-off-by: Yi Chen <chenyi2000@zju.edu.cn>
Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
Reviewed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20230406101559.39632-1-chenyi2000@zju.edu.cn>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Zicbom is the Cache-Block Management extension defined in the already
ratified RISC-V Base Cache Management Operation (CBO) ISA extension [1].
The extension contains three instructions: cbo.clean, cbo.flush and
cbo.inval. All of them must be implemented in the same group as LQ and
cbo.zero due to overlapping patterns.
All these instructions can throw a Illegal Instruction/Virtual
Instruction exception, similar to the existing cbo.zero. The same
check_zicbo_envcfg() is used to handle these exceptions.
Aside from that, these instructions also need to handle page faults and
guest page faults. This is done in a new check_zicbom_access() helper.
As with Zicboz, the cache block size for Zicbom is also configurable.
Note that the spec determines that Zicbo[mp] and Zicboz can have
different cache sizes (Section 2.7 of [1]), so we also include a
'cbom_blocksize' to go along with the existing 'cboz_blocksize'. They
are set to the same size, so unless users want to play around with the
settings both sizes will be the same.
[1] https://github.com/riscv/riscv-CMOs/blob/master/specifications/cmobase-v1.0.1.pdf
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
Co-developed-by: Philipp Tomsich <philipp.tomsich@vrull.eu>
Signed-off-by: Christoph Muellner <cmuellner@linux.com>
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Message-ID: <20230224132536.552293-4-dbarboza@ventanamicro.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
The RISC-V base cache management operation (CBO) ISA extension has been
ratified. It defines three extensions: Cache-Block Management, Cache-Block
Prefetch and Cache-Block Zero. More information about the spec can be
found at [1].
Let's start by implementing the Cache-Block Zero extension, Zicboz. It
uses the cbo.zero instruction that, as with all CBO instructions that
will be added later, needs to be implemented in an overlap group with
the LQ instruction due to overlapping patterns.
cbo.zero throws a Illegal Instruction/Virtual Instruction exception
depending on CSR state. This is also the case for the remaining cbo
instructions we're going to add next, so create a check_zicbo_envcfg()
that will be used by all Zicbo[mz] instructions.
[1] https://github.com/riscv/riscv-CMOs/blob/master/specifications/cmobase-v1.0.1.pdf
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Co-developed-by: Philipp Tomsich <philipp.tomsich@vrull.eu>
Signed-off-by: Christoph Muellner <cmuellner@linux.com>
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
Message-ID: <20230224132536.552293-3-dbarboza@ventanamicro.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
The priv spec v1.12 says:
If no PMP entry matches an M-mode access, the access succeeds. If
no PMP entry matches an S-mode or U-mode access, but at least one
PMP entry is implemented, the access fails. Failed accesses generate
an instruction, load, or store access-fault exception.
At present the exception cause is set to 'illegal instruction' but
should have been 'instruction access fault'.
Fixes: d102f19a20 ("target/riscv/pmp: Raise exception if no PMP entry is configured")
Signed-off-by: Bin Meng <bmeng@tinylab.org>
Reviewed-by: Wilfred Mallawa <wilfred.mallawa@wdc.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20221205065303.204095-1-bmeng@tinylab.org>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Introduce csrr and csrw helpers, for read-only and write-only insns.
Note that we do not properly implement this in riscv_csrrw, in that
we cannot distinguish true read-only (rs1 == 0) from any other zero
write_mask another source register -- this should still raise an
exception for read-only registers.
Only issue gen_io_start for CF_USE_ICOUNT.
Use ctx->zero for csrrc.
Use get_gpr and dest_gpr.
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20210823195529.560295-19-richard.henderson@linaro.org
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
The wfi exception trigger behavior should take into account user mode,
hstatus.vtw, and the fact the an wfi might raise different types of
exceptions depending on various factors:
If supervisor mode is not present:
- an illegal instruction exception should be generated if user mode
executes and wfi instruction and mstatus.tw = 1.
If supervisor mode is present:
- when a wfi instruction is executed, an illegal exception should be triggered
if either the current mode is user or the mode is supervisor and mstatus.tw is
set.
Plus, if the hypervisor extensions are enabled:
- a virtual instruction exception should be raised when a wfi is executed from
virtual-user or virtual-supervisor and hstatus.vtw is set.
Signed-off-by: Jose Martins <josemartins90@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20210420213656.85148-1-josemartins90@gmail.com
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Currently we log interrupts and exceptions using the trace backend in
riscv_cpu_do_interrupt(). We also log exceptions using the interrupt log
mask (-d int) in riscv_raise_exception().
This patch converts riscv_cpu_do_interrupt() to log both interrupts and
exceptions with the interrupt log mask, so that both are printed when a
user runs QEMU with -d int.
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 29a8c766c7c4748d0f2711c3a0abb81208138c5e.1601652179.git.alistair.francis@wdc.com
Call the helper_hyp_tlb_flush() function on hfence instructions which
will generate an illegal insruction execption if we don't have
permission to flush the Hypervisor level TLBs.
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
