write_misa() must use as much common logic as possible. We want to open
code just the bits that are exclusive to the CSR write operation and TCG
internals.
Our validation is done with riscv_cpu_validate_set_extensions(), but we
need a small tweak first. When enabling RVG we're doing:
env->misa_ext |= RVI | RVM | RVA | RVF | RVD;
env->misa_ext_mask = env->misa_ext;
This works fine for realize() time but this can potentially overwrite
env->misa_ext_mask if we reutilize the function for write_misa().
Instead of doing misa_ext_mask = misa_ext, sum up the RVG extensions in
misa_ext_mask as well. This won't change realize() time behavior
(misa_ext_mask will be == misa_ext) and will ensure that write_misa()
won't change misa_ext_mask by accident.
After that, rewrite write_misa() to work as follows:
- mask the write using misa_ext_mask to avoid enabling unsupported
extensions;
- suppress RVC if the next insn isn't aligned;
- disable RVG if any of RVG dependencies are being disabled by the user;
- assign env->misa_ext and run riscv_cpu_validate_set_extensions(). On
error, rollback env->misa_ext to its original value, logging a
GUEST_ERROR to inform the user about the failed write;
- handle RVF and MSTATUS_FS and continue as usual.
Let's keep write_misa() as experimental for now until this logic gains
enough mileage.
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Message-Id: <20230517135714.211809-12-dbarboza@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>
RISC-V specifies multiple sizes for addressable memory and Linux probes for
the machine's support at startup via the satp CSR register (done in
csr.c:validate_vm).
As per the specification, sv64 must support sv57, which in turn must
support sv48...etc. So we can restrict machine support by simply setting the
"highest" supported mode and the bare mode is always supported.
You can set the satp mode using the new properties "sv32", "sv39", "sv48",
"sv57" and "sv64" as follows:
-cpu rv64,sv57=on # Linux will boot using sv57 scheme
-cpu rv64,sv39=on # Linux will boot using sv39 scheme
-cpu rv64,sv57=off # Linux will boot using sv48 scheme
-cpu rv64 # Linux will boot using sv57 scheme by default
We take the highest level set by the user:
-cpu rv64,sv48=on,sv57=on # Linux will boot using sv57 scheme
We make sure that invalid configurations are rejected:
-cpu rv64,sv39=off,sv48=on # sv39 must be supported if higher modes are
# enabled
We accept "redundant" configurations:
-cpu rv64,sv48=on,sv57=off # Linux will boot using sv48 scheme
And contradictory configurations:
-cpu rv64,sv48=on,sv48=off # Linux will boot using sv39 scheme
Co-Developed-by: Ludovic Henry <ludovic@rivosinc.com>
Signed-off-by: Ludovic Henry <ludovic@rivosinc.com>
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Bin Meng <bmeng@tinylab.org>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Frank Chang <frank.chang@sifive.com>
Message-ID: <20230303131252.892893-4-alexghiti@rivosinc.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Daniel Henrique Barboza <dbarboza@ventanamicro.com> says:
These cleanups were suggested by LIU Zhiwei during the review of
d3e6d5762b ("Merge patch series "make write_misa a no-op and FEATURE_*
cleanups"").
* b4-shazam-merge:
target/riscv/csr.c: avoid env_archcpu() usages when reading RISCVCPUConfig
target/riscv/csr.c: use riscv_cpu_cfg() to avoid env_cpu() pointers
target/riscv/csr.c: simplify mctr()
target/riscv/csr.c: use env_archcpu() in ctr()
Message-ID: <20230224174520.92490-1-dbarboza@ventanamicro.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Weiwei Li <liweiwei@iscas.ac.cn> says:
This patchset adds support svadu extension. It also fixes some
relationship between *envcfg fields and Svpbmt/Sstc extensions.
Specification for Svadu extension can be found in:
https://github.com/riscv/riscv-svadu
* b4-shazam-merge:
target/riscv: Export Svadu property
target/riscv: Add *envcfg.HADE related check in address translation
target/riscv: Add *envcfg.PBMTE related check in address translation
target/riscv: Add csr support for svadu
target/riscv: Fix the relationship of PBMTE/STCE fields between menvcfg and henvcfg
target/riscv: Fix the relationship between menvcfg.PBMTE/STCE and Svpbmt/Sstc extensions
Message-ID: <20230224040852.37109-1-liweiwei@iscas.ac.cn>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Bin Meng <bmeng@tinylab.org> says:
At present gdbstub reports an incorrect / incomplete CSR list in the
target description XML, for example:
- menvcfg is reported in 'sifive_u' machine
- fcsr is missing in a F/D enabled processor
The issue is caused by:
- priv spec version check is missing when reporting CSRs
- CSR predicate() routine is called without turning on the debugger flag
* b4-shazam-merge:
target/riscv: Group all predicate() routines together
target/riscv: Drop priv level check in mseccfg predicate()
target/riscv: Allow debugger to access sstc CSRs
target/riscv: Allow debugger to access {h, s}stateen CSRs
target/riscv: Allow debugger to access seed CSR
target/riscv: Allow debugger to access user timer and counter CSRs
target/riscv: gdbstub: Drop the vector CSRs in riscv-vector.xml
target/riscv: gdbstub: Turn on debugger mode before calling CSR predicate()
target/riscv: Avoid reporting odd-numbered pmpcfgX in the CSR XML for RV64
target/riscv: Simplify getting RISCVCPU pointer from env
target/riscv: Simplify {read, write}_pmpcfg() a little bit
target/riscv: Use 'bool' type for read_only
target/riscv: Coding style fixes in csr.c
target/riscv: gdbstub: Do not generate CSR XML if Zicsr is disabled
target/riscv: gdbstub: Minor change for better readability
target/riscv: Use g_assert() for the predicate() NULL check
target/riscv: Add some comments to clarify the priority policy of riscv_csrrw_check()
target/riscv: gdbstub: Check priv spec version before reporting CSR
Message-ID: <20230228104035.1879882-1-bmeng@tinylab.org>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
riscv_csrrw_check() already does the generic privilege level check
hence there is no need to do the specific M-mode access check in
the mseccfg predicate().
With this change debugger can access the mseccfg CSR anytime.
Signed-off-by: Bin Meng <bmeng@tinylab.org>
Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
Message-ID: <20230228104035.1879882-18-bmeng@tinylab.org>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
At present with a debugger attached sstc CSRs can only be accssed
when CPU is in M-mode, or configured correctly.
Fix it by adjusting their predicate() routine logic so that the
static config check comes before the run-time check, as well as
adding a debugger check.
Signed-off-by: Bin Meng <bmeng@tinylab.org>
Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
Message-ID: <20230228104035.1879882-17-bmeng@tinylab.org>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
At present {h,s}stateen CSRs are not reported in the CSR XML
hence gdb cannot access them.
Fix it by adjusting their predicate() routine logic so that the
static config check comes before the run-time check, as well as
adding a debugger check.
Signed-off-by: Bin Meng <bmeng@tinylab.org>
Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
Message-ID: <20230228104035.1879882-16-bmeng@tinylab.org>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
At present the odd-numbered PMP configuration registers for RV64 are
reported in the CSR XML by QEMU gdbstub. However these registers do
not exist on RV64 so trying to access them from gdb results in 'E14'.
Move the pmpcfgX index check from the actual read/write routine to
the PMP CSR predicate() routine, so that non-existent pmpcfgX won't
be reported in the CSR XML for RV64.
Signed-off-by: Bin Meng <bmeng@tinylab.org>
Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
Reviewed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Message-ID: <20230228104035.1879882-11-bmeng@tinylab.org>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
At present riscv_csrrw_check() checks the CSR predicate() against
NULL and throws RISCV_EXCP_ILLEGAL_INST if it is NULL. But this is
a pure software check, and has nothing to do with the emulation of
the hardware behavior, thus it is inappropriate to return illegal
instruction exception when software forgets to install the hook.
Change to use g_assert() instead.
Signed-off-by: Bin Meng <bmeng@tinylab.org>
Reviewed-by: Weiwei Li<liweiwei@iscas.ac.cn>
Message-ID: <20230228104035.1879882-4-bmeng@tinylab.org>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
The priority policy of riscv_csrrw_check() was once adjusted in
commit eacaf44019 ("target/riscv: Fix priority of csr related check in riscv_csrrw_check")
whose commit message says the CSR existence check should come before
the access control check, but the code changes did not agree with
the commit message, that the predicate() check actually came after
the read / write check.
In fact this was intentional. Add some comments there so that people
won't bother trying to change it without a solid reason.
Signed-off-by: Bin Meng <bmeng@tinylab.org>
Reviewed-by: Weiwei Li<liweiwei@iscas.ac.cn>
Message-ID: <20230228104035.1879882-3-bmeng@tinylab.org>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
RISC-V defines a handful of extensions related to floating point, along
with various relationships between these and other extensions. This
patch set adds support for the Zvfh, Zvhfmin, and Zve64d extensions;
along with a handful of fixes and cleanups related to the other
floating-point extension relationships.
* b4-shazam-merge
target/riscv: Expose properties for Zv* extensions
target/riscv: Simplify check for EEW = 64 in trans_rvv.c.inc
target/riscv: Fix check for vector load/store instructions when EEW=64
target/riscv: Add support for Zvfh/zvfhmin extensions
target/riscv: Remove rebundunt check for zve32f and zve64f
target/riscv: Replace check for F/D to Zve32f/Zve64d in trans_rvv.c.inc
target/riscv: Simplify check for Zve32f and Zve64f
target/riscv: Indent fixes in cpu.c
target/riscv: Add propertie check for Zvfh{min} extensions
target/riscv: Fix relationship between V, Zve*, F and D
target/riscv: Add cfg properties for Zv* extensions
target/riscv: Simplify the check for Zfhmin and Zhinxmin
target/riscv: Fix the relationship between Zhinxmin and Zhinx
target/riscv: Fix the relationship between Zfhmin and Zfh
Message-ID: <20230215020539.4788-1-liweiwei@iscas.ac.cn>
[Palmer: commit text]
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
RISCV_FEATURE_MMU is set whether cpu->cfg.mmu is set, so let's just use
the flag directly instead.
With this change the enum is also removed. It is worth noticing that
this enum, and all the RISCV_FEATURES_* that were contained in it,
predates the existence of the cpu->cfg object. Today, using cpu->cfg is
an easier way to retrieve all the features and extensions enabled in the
hart.
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
Reviewed-by: Bin Meng <bmeng@tinylab.org>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Message-ID: <20230222185205.355361-10-dbarboza@ventanamicro.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
At this moment, and apparently since ever, we have no way of enabling
RISCV_FEATURE_MISA. This means that all the code from write_misa(), all
the nuts and bolts that handles how to properly write this CSR, has
always been a no-op as well because write_misa() will always exit
earlier.
This seems to be benign in the majority of cases. Booting an Ubuntu
'virt' guest and logging all the calls to 'write_misa' shows that no
writes to MISA CSR was attempted. Writing MISA, i.e. enabling/disabling
RISC-V extensions after the machine is powered on, seems to be a niche
use.
After discussions in the mailing list, most notably in [1], we reached
the consensus that this code is not suited to be exposed to users
because it's not well tested, but at the same time removing it is a bit
extreme because we would like to fix it, and it's easier to do so with
the code available to use instead of fetching it from git log.
The approach taken here is to get rid of RISCV_FEATURE_MISA altogether
and use a new experimental flag called x-misa-w. The default value is
false, meaning that we're keeping the existing behavior of doing nothing
if a write_misa() is attempted. As with any existing experimental flag,
x-misa-w is also a temporary flag that we need to remove once we fix
write_misa().
[1] https://lists.gnu.org/archive/html/qemu-devel/2023-02/msg05092.html
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Bin Meng <bmeng@tinylab.org>
Reviewed-by: Weiwei Li<liweiwei@iscas.ac.cn>
Reviewed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Message-ID: <20230222185205.355361-4-dbarboza@ventanamicro.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
The masking done using env->misa_ext_mask already filters any extension
that QEMU doesn't support. If the hart supports the extension then QEMU
supports it as well.
If the masking done by env->misa_ext_mask is somehow letting unsupported
QEMU extensions pass by, misa_ext_mask itself needs to be fixed instead.
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
Reviewed-by: Bin Meng <bmeng@tinylab.org>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Message-ID: <20230222185205.355361-3-dbarboza@ventanamicro.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
