Move the following TCG-specific cpu_loop_exit_*() declarations
out of the generic "exec/cpu-common.h" header, to the recently
created "accel/tcg/cpu-loop.h" one, documenting them:
- cpu_loop_exit_noexc()
- cpu_loop_exit_atomic()
- cpu_loop_exit_restore()
- cpu_loop_exit()
Include "accel/tcg/cpu-loop.h" where appropriate.
Signed-off-by: Philippe Mathieu-Daudé <philmd@oss.qualcomm.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20260617171438.75914-11-philmd@oss.qualcomm.com>
Most of these definitions save riscv_csrr, riscv_csrrw, riscv_csr_read,
riscv_csr_write are only used in target/. Move declarations to a
separate headers which will soon be made internal to target/.
csr.h is temporarily included from cpu.h to not break includes from
outside target/, this include will be removed in the following commit.
Signed-off-by: Anton Johansson <anjo@rev.ng>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20260520125406.28693-24-anjo@rev.ng>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
According to the RISC-V Privileged Architecture specification, the low
bit of MEPC/SEPC must always be zero. When IALIGN=32, the two low bits
must be zero.
This commit fixes the behavior of MEPC/SEPC CSR reads and writes, and
the implicit reads by MRET/SRET instructions to properly mask the
lowest bit(s) based on whether the C extension is enabled:
- When C extension is enabled (IALIGN=16): mask bit 0
- When C extension is disabled (IALIGN=32): mask bits [1:0]
Previously, when vectored mode bits from STVEC (which sets bit 0 for
vectored mode) were written to MEPC, the bits would not be cleared
correctly, causing incorrect behavior on MRET.
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2855
Signed-off-by: Charalampos Mitrodimas <charmitro@posteo.net>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Message-ID: <20250703182157.281320-2-charmitro@posteo.net>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
When the Ssdbltrp extension is enabled, SSTATUS.SDT field is cleared
when executing sret. When executing mret/mnret, SSTATUS.SDT is cleared
when returning to U, VS or VU and VSSTATUS.SDT is cleared when returning
to VU from HS.
Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20250110125441.3208676-4-cleger@rivosinc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Zicfilp extension introduces the MNPELP (bit 9) in mnstatus.
The MNPELP field holds the previous ELP.
When a RNMI trap is delivered, the MNPELP is set to ELP and ELP set
to NO_LP_EXPECTED. Upon a mnret, if the mnstatus.MNPP holds the
value y, then ELP is set to the value of MNPELP if yLPE is 1;
otherwise, it is set to NO_LP_EXPECTED.
Signed-off-by: Frank Chang <frank.chang@sifive.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20250106054336.1878291-7-frank.chang@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
When using system mode we can get the CPU traps being taken via the
'riscv_trap' trace or the "-d int" qemu log. User mode does not a way of
logging/showing exceptions to users.
Add a trace in riscv_raise_exception() to allow qemu-riscv(32/64) users
to check all exceptions being thrown. This is particularly useful to
help identifying insns that are throwing SIGILLs.
As it is today we need to debug their binaries to identify where the
illegal insns are:
$ ~/work/qemu/build/qemu-riscv64 -cpu rv64 ./foo.out
Illegal instruction (core dumped)
After this change users can capture the trace and use EPC to pinpoint
the insn:
$ ~/work/qemu/build/qemu-riscv64 -cpu rv64 -trace riscv_exception ./foo.out
riscv_exception 8 (user_ecall) on epc 0x17cd2
riscv_exception 8 (user_ecall) on epc 0x17cda
riscv_exception 8 (user_ecall) on epc 0x17622
(...)
riscv_exception 2 (illegal_instruction) on epc 0x1053a
Illegal instruction (core dumped)
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20250106173734.412353-3-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Do a cosmetic change in riscv_raise_exception() to change 'exception'
type from uint32_t to RISCVException, making it a bit clear that the
arg is directly correlated to the RISCVException enum.
As a side effect, change 'excp' type from int to RISCVException in
generate_exception() to guarantee that all callers of
riscv_raise_exception() will use the enum.
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20250106173734.412353-2-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
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>
