target/riscv: raise an exception when CSRRS/CSRRC writes a read-only CSR

Both CSRRS and CSRRC always read the addressed CSR and cause any read side
effects regardless of rs1 and rd fields. Note that

target/riscv: raise an exception when CSRRS/CSRRC writes a read-only CSR

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>

show more ...

target/riscv: Save counter values during countinhibit update

Currently, if a counter monitoring cycle/instret is stopped via
mcountinhibit we just update the state while the value is saved
during th

target/riscv: Save counter values during countinhibit update

Currently, if a counter monitoring cycle/instret is stopped via
mcountinhibit we just update the state while the value is saved
during the next read. This is not accurate as the read may happen
many cycles after the counter is stopped. Ideally, the read should
return the value saved when the counter is stopped.

Thus, save the value of the counter during the inhibit update
operation and return that value during the read if corresponding bit
in mcountihibit is set.

Acked-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Message-ID: <20240711-smcntrpmf_v7-v8-8-b7c38ae7b263@rivosinc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

show more ...

target/riscv: Implement privilege mode filtering for cycle/instret

Privilege mode filtering can also be emulated for cycle/instret by
tracking host_ticks/icount during each privilege mode switch. Th

target/riscv: Implement privilege mode filtering for cycle/instret

Privilege mode filtering can also be emulated for cycle/instret by
tracking host_ticks/icount during each privilege mode switch. This
patch implements that for both cycle/instret and mhpmcounters. The
first one requires Smcntrpmf while the other one requires Sscofpmf
to be enabled.

The cycle/instret are still computed using host ticks when icount
is not enabled. Otherwise, they are computed using raw icount which
is more accurate in icount mode.

Co-Developed-by: Rajnesh Kanwal <rkanwal@rivosinc.com>
Signed-off-by: Rajnesh Kanwal <rkanwal@rivosinc.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Message-ID: <20240711-smcntrpmf_v7-v8-7-b7c38ae7b263@rivosinc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

show more ...

target/riscv: Add cycle & instret privilege mode filtering definitions

This adds the definitions for ISA extension smcntrpmf.

Signed-off-by: Kaiwen Xue <kaiwenx@rivosinc.com>
Reviewed-by: Daniel He

target/riscv: Add cycle & instret privilege mode filtering definitions

This adds the definitions for ISA extension smcntrpmf.

Signed-off-by: Kaiwen Xue <kaiwenx@rivosinc.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Message-ID: <20240711-smcntrpmf_v7-v8-4-b7c38ae7b263@rivosinc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

show more ...

target/riscv: Combine set_mode and set_virt functions.

Combining riscv_cpu_set_virt_enabled() and riscv_cpu_set_mode()
functions. This is to make complete mode change information
available through a

target/riscv: Combine set_mode and set_virt functions.

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>

show more ...

target/riscv: Introduce extension implied rules definition

RISCVCPUImpliedExtsRule is created to store the implied rules.
'is_misa' flag is used to distinguish whether the rule is derived
from the M

target/riscv: Introduce extension implied rules definition

RISCVCPUImpliedExtsRule is created to store the implied rules.
'is_misa' flag is used to distinguish whether the rule is derived
from the MISA or other extensions.
'ext' stores the MISA bit if 'is_misa' is true. Otherwise, it stores
the offset of the extension defined in RISCVCPUConfig. 'ext' will also
serve as the key of the hash tables to look up the rule in the following
commit.

Signed-off-by: Frank Chang <frank.chang@sifive.com>
Reviewed-by: Jerry Zhang Jian <jerry.zhangjian@sifive.com>
Tested-by: Max Chou <max.chou@sifive.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20240625114629.27793-2-frank.chang@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

show more ...

target/riscv: Define macros and variables for ss1p13

Add macros and variables for RISC-V privilege 1.13 support.

Signed-off-by: Fea.Wang <fea.wang@sifive.com>
Reviewed-by: Frank Chang <frank.chang@

target/riscv: Define macros and variables for ss1p13

Add macros and variables for RISC-V privilege 1.13 support.

Signed-off-by: Fea.Wang <fea.wang@sifive.com>
Reviewed-by: Frank Chang <frank.chang@sifive.com>
Reviewed-by: Weiwei Li <liwei1518@gmail.com>
Reviewed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20240606135454.119186-3-fea.wang@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

show more ...

target/riscv: Reuse the conversion function of priv_spec

Public the conversion function of priv_spec in cpu.h, so that tcg-cpu.c
could also use it.

Signed-off-by: Jim Shu <jim.shu@sifive.com>
Signe

target/riscv: Reuse the conversion function of priv_spec

Public the conversion function of priv_spec in cpu.h, so that tcg-cpu.c
could also use it.

Signed-off-by: Jim Shu <jim.shu@sifive.com>
Signed-off-by: Fea.Wang <fea.wang@sifive.com>
Reviewed-by: Frank Chang <frank.chang@sifive.com>
Reviewed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20240606135454.119186-2-fea.wang@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

show more ...

riscv: thead: Add th.sxstatus CSR emulation

The th.sxstatus CSR can be used to identify available custom extension
on T-Head CPUs. The CSR is documented here:
https://github.com/T-head-Semi/thead-

riscv: thead: Add th.sxstatus CSR emulation

The th.sxstatus CSR can be used to identify available custom extension
on T-Head CPUs. The CSR is documented here:
https://github.com/T-head-Semi/thead-extension-spec/blob/master/xtheadsxstatus.adoc

An important property of this patch is, that the th.sxstatus MAEE field
is not set (indicating that XTheadMae is not available).
XTheadMae is a memory attribute extension (similar to Svpbmt) which is
implemented in many T-Head CPUs (C906, C910, etc.) and utilizes bits
in PTEs that are marked as reserved. QEMU maintainers prefer to not
implement XTheadMae, so we need give kernels a mechanism to identify
if XTheadMae is available in a system or not. And this patch introduces
this mechanism in QEMU in a way that's compatible with real HW
(i.e., probing the th.sxstatus.MAEE bit).

Further context can be found on the list:
https://lists.gnu.org/archive/html/qemu-devel/2024-02/msg00775.html

Reviewed-by: LIU Zhiwei <zhiwe_liu@linux.alibaba.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
Message-ID: <20240429073656.2486732-1-christoph.muellner@vrull.eu>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

show more ...

target/riscv: Implement dynamic establishment of custom decoder

In this patch, we modify the decoder to be a freely composable data
structure instead of a hardcoded one. It can be dynamically builde

target/riscv: Implement dynamic establishment of custom decoder

In this patch, we modify the decoder to be a freely composable data
structure instead of a hardcoded one. It can be dynamically builded up
according to the extensions.
This approach has several benefits:
1. Provides support for heterogeneous cpu architectures. As we add decoder in
RISCVCPU, each cpu can have their own decoder, and the decoders can be
different due to cpu's features.
2. Improve the decoding efficiency. We run the guard_func to see if the decoder
can be added to the dynamic_decoder when building up the decoder. Therefore,
there is no need to run the guard_func when decoding each instruction. It can
improve the decoding efficiency
3. For vendor or dynamic cpus, it allows them to customize their own decoder
functions to improve decoding efficiency, especially when vendor-defined
instruction sets increase. Because of dynamic building up, it can skip the other
decoder guard functions when decoding.
4. Pre patch for allowing adding a vendor decoder before decode_insn32() with minimal
overhead for users that don't need this particular vendor decoder.

Signed-off-by: Huang Tao <eric.huang@linux.alibaba.com>
Suggested-by: Christoph Muellner <christoph.muellner@vrull.eu>
Co-authored-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20240506023607.29544-1-eric.huang@linux.alibaba.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

show more ...

target/riscv/kvm: Fix exposure of Zkr

The Zkr extension may only be exposed to KVM guests if the VMM
implements the SEED CSR. Use the same implementation as TCG.

Without this patch, running with a

target/riscv/kvm: Fix exposure of Zkr

The Zkr extension may only be exposed to KVM guests if the VMM
implements the SEED CSR. Use the same implementation as TCG.

Without this patch, running with a KVM which does not forward the
SEED CSR access to QEMU will result in an ILL exception being
injected into the guest (this results in Linux guests crashing on
boot). And, when running with a KVM which does forward the access,
QEMU will crash, since QEMU doesn't know what to do with the exit.

Fixes: 3108e2f1c69d ("target/riscv/kvm: update KVM exts to Linux 6.8")
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Cc: qemu-stable <qemu-stable@nongnu.org>
Message-ID: <20240422134605.534207-2-ajones@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

show more ...

target/riscv: Restrict riscv_cpu_do_interrupt() to sysemu

riscv_cpu_do_interrupt() is not reachable on user emulation.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Daniel

target/riscv: Restrict riscv_cpu_do_interrupt() to sysemu

riscv_cpu_do_interrupt() is not reachable on user emulation.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20230626232007.8933-7-philmd@linaro.org>

show more ...

riscv: thead: Add th.sxstatus CSR emulation

The th.sxstatus CSR can be used to identify available custom extension
on T-Head CPUs. The CSR is documented here:
https://github.com/T-head-Semi/thead-

riscv: thead: Add th.sxstatus CSR emulation

The th.sxstatus CSR can be used to identify available custom extension
on T-Head CPUs. The CSR is documented here:
https://github.com/T-head-Semi/thead-extension-spec/blob/master/xtheadsxstatus.adoc

An important property of this patch is, that the th.sxstatus MAEE field
is not set (indicating that XTheadMae is not available).
XTheadMae is a memory attribute extension (similar to Svpbmt) which is
implemented in many T-Head CPUs (C906, C910, etc.) and utilizes bits
in PTEs that are marked as reserved. QEMU maintainers prefer to not
implement XTheadMae, so we need give kernels a mechanism to identify
if XTheadMae is available in a system or not. And this patch introduces
this mechanism in QEMU in a way that's compatible with real HW
(i.e., probing the th.sxstatus.MAEE bit).

Further context can be found on the list:
https://lists.gnu.org/archive/html/qemu-devel/2024-02/msg00775.html

Reviewed-by: LIU Zhiwei <zhiwe_liu@linux.alibaba.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
Message-ID: <20240429073656.2486732-1-christoph.muellner@vrull.eu>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

show more ...

target/riscv: Implement dynamic establishment of custom decoder

In this patch, we modify the decoder to be a freely composable data
structure instead of a hardcoded one. It can be dynamically builde

target/riscv: Implement dynamic establishment of custom decoder

In this patch, we modify the decoder to be a freely composable data
structure instead of a hardcoded one. It can be dynamically builded up
according to the extensions.
This approach has several benefits:
1. Provides support for heterogeneous cpu architectures. As we add decoder in
RISCVCPU, each cpu can have their own decoder, and the decoders can be
different due to cpu's features.
2. Improve the decoding efficiency. We run the guard_func to see if the decoder
can be added to the dynamic_decoder when building up the decoder. Therefore,
there is no need to run the guard_func when decoding each instruction. It can
improve the decoding efficiency
3. For vendor or dynamic cpus, it allows them to customize their own decoder
functions to improve decoding efficiency, especially when vendor-defined
instruction sets increase. Because of dynamic building up, it can skip the other
decoder guard functions when decoding.
4. Pre patch for allowing adding a vendor decoder before decode_insn32() with minimal
overhead for users that don't need this particular vendor decoder.

Signed-off-by: Huang Tao <eric.huang@linux.alibaba.com>
Suggested-by: Christoph Muellner <christoph.muellner@vrull.eu>
Co-authored-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20240506023607.29544-1-eric.huang@linux.alibaba.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

show more ...

target/riscv/kvm: Fix exposure of Zkr

The Zkr extension may only be exposed to KVM guests if the VMM
implements the SEED CSR. Use the same implementation as TCG.

Without this patch, running with a

target/riscv/kvm: Fix exposure of Zkr

The Zkr extension may only be exposed to KVM guests if the VMM
implements the SEED CSR. Use the same implementation as TCG.

Without this patch, running with a KVM which does not forward the
SEED CSR access to QEMU will result in an ILL exception being
injected into the guest (this results in Linux guests crashing on
boot). And, when running with a KVM which does forward the access,
QEMU will crash, since QEMU doesn't know what to do with the exit.

Fixes: 3108e2f1c69d ("target/riscv/kvm: update KVM exts to Linux 6.8")
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Cc: qemu-stable <qemu-stable@nongnu.org>
Message-ID: <20240422134605.534207-2-ajones@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

show more ...

riscv: thead: Add th.sxstatus CSR emulation

The th.sxstatus CSR can be used to identify available custom extension
on T-Head CPUs. The CSR is documented here:
https://github.com/T-head-Semi/thead-

riscv: thead: Add th.sxstatus CSR emulation

The th.sxstatus CSR can be used to identify available custom extension
on T-Head CPUs. The CSR is documented here:
https://github.com/T-head-Semi/thead-extension-spec/blob/master/xtheadsxstatus.adoc

An important property of this patch is, that the th.sxstatus MAEE field
is not set (indicating that XTheadMae is not available).
XTheadMae is a memory attribute extension (similar to Svpbmt) which is
implemented in many T-Head CPUs (C906, C910, etc.) and utilizes bits
in PTEs that are marked as reserved. QEMU maintainers prefer to not
implement XTheadMae, so we need give kernels a mechanism to identify
if XTheadMae is available in a system or not. And this patch introduces
this mechanism in QEMU in a way that's compatible with real HW
(i.e., probing the th.sxstatus.MAEE bit).

Further context can be found on the list:
https://lists.gnu.org/archive/html/qemu-devel/2024-02/msg00775.html

Reviewed-by: LIU Zhiwei <zhiwe_liu@linux.alibaba.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
Message-ID: <20240429073656.2486732-1-christoph.muellner@vrull.eu>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

show more ...

target/riscv: Implement dynamic establishment of custom decoder

In this patch, we modify the decoder to be a freely composable data
structure instead of a hardcoded one. It can be dynamically builde

target/riscv: Implement dynamic establishment of custom decoder

In this patch, we modify the decoder to be a freely composable data
structure instead of a hardcoded one. It can be dynamically builded up
according to the extensions.
This approach has several benefits:
1. Provides support for heterogeneous cpu architectures. As we add decoder in
RISCVCPU, each cpu can have their own decoder, and the decoders can be
different due to cpu's features.
2. Improve the decoding efficiency. We run the guard_func to see if the decoder
can be added to the dynamic_decoder when building up the decoder. Therefore,
there is no need to run the guard_func when decoding each instruction. It can
improve the decoding efficiency
3. For vendor or dynamic cpus, it allows them to customize their own decoder
functions to improve decoding efficiency, especially when vendor-defined
instruction sets increase. Because of dynamic building up, it can skip the other
decoder guard functions when decoding.
4. Pre patch for allowing adding a vendor decoder before decode_insn32() with minimal
overhead for users that don't need this particular vendor decoder.

Signed-off-by: Huang Tao <eric.huang@linux.alibaba.com>
Suggested-by: Christoph Muellner <christoph.muellner@vrull.eu>
Co-authored-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20240506023607.29544-1-eric.huang@linux.alibaba.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

show more ...

target/riscv/kvm: Fix exposure of Zkr

The Zkr extension may only be exposed to KVM guests if the VMM
implements the SEED CSR. Use the same implementation as TCG.

Without this patch, running with a

target/riscv/kvm: Fix exposure of Zkr

The Zkr extension may only be exposed to KVM guests if the VMM
implements the SEED CSR. Use the same implementation as TCG.

Without this patch, running with a KVM which does not forward the
SEED CSR access to QEMU will result in an ILL exception being
injected into the guest (this results in Linux guests crashing on
boot). And, when running with a KVM which does forward the access,
QEMU will crash, since QEMU doesn't know what to do with the exit.

Fixes: 3108e2f1c69d ("target/riscv/kvm: update KVM exts to Linux 6.8")
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Cc: qemu-stable <qemu-stable@nongnu.org>
Message-ID: <20240422134605.534207-2-ajones@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

show more ...

target: Define TCG_GUEST_DEFAULT_MO in 'cpu-param.h'

accel/tcg/ files requires the following definitions:

- TARGET_LONG_BITS
- TARGET_PAGE_BITS
- TARGET_PHYS_ADDR_SPACE_BITS
- TCG_GUEST_DEF

target: Define TCG_GUEST_DEFAULT_MO in 'cpu-param.h'

accel/tcg/ files requires the following definitions:

- TARGET_LONG_BITS
- TARGET_PAGE_BITS
- TARGET_PHYS_ADDR_SPACE_BITS
- TCG_GUEST_DEFAULT_MO

The first 3 are defined in "cpu-param.h". The last one
in "cpu.h", with a bunch of definitions irrelevant for
TCG. By moving the TCG_GUEST_DEFAULT_MO definition to
"cpu-param.h", we can simplify various accel/tcg includes.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Acked-by: Nicholas Piggin <npiggin@gmail.com>
Message-Id: <20231211212003.21686-4-philmd@linaro.org>

show more ...

target: Define TCG_GUEST_DEFAULT_MO in 'cpu-param.h'

accel/tcg/ files requires the following definitions:

- TARGET_LONG_BITS
- TARGET_PAGE_BITS
- TARGET_PHYS_ADDR_SPACE_BITS
- TCG_GUEST_DEF

target: Define TCG_GUEST_DEFAULT_MO in 'cpu-param.h'

accel/tcg/ files requires the following definitions:

- TARGET_LONG_BITS
- TARGET_PAGE_BITS
- TARGET_PHYS_ADDR_SPACE_BITS
- TCG_GUEST_DEFAULT_MO

The first 3 are defined in "cpu-param.h". The last one
in "cpu.h", with a bunch of definitions irrelevant for
TCG. By moving the TCG_GUEST_DEFAULT_MO definition to
"cpu-param.h", we can simplify various accel/tcg includes.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Acked-by: Nicholas Piggin <npiggin@gmail.com>
Message-Id: <20231211212003.21686-4-philmd@linaro.org>

show more ...

target/riscv: mcountinhibit, mcounteren, scounteren, hcounteren is 32-bit

mcountinhibit, mcounteren, scounteren and hcounteren must always be 32-bit
by privileged spec

Signed-off-by: Vadim Shakirov

target/riscv: mcountinhibit, mcounteren, scounteren, hcounteren is 32-bit

mcountinhibit, mcounteren, scounteren and hcounteren must always be 32-bit
by privileged spec

Signed-off-by: Vadim Shakirov <vadim.shakirov@syntacore.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Message-ID: <20240202113919.18236-1-vadim.shakirov@syntacore.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

show more ...

target/riscv: Use GDBFeature for dynamic XML

In preparation for a change to use GDBFeature as a parameter of
gdb_register_coprocessor(), convert the internal representation of
dynamic feature from p

target/riscv: Use GDBFeature for dynamic XML

In preparation for a change to use GDBFeature as a parameter of
gdb_register_coprocessor(), convert the internal representation of
dynamic feature from plain XML to GDBFeature.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Message-Id: <20231213-gdb-v17-3-777047380591@daynix.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240227144335.1196131-8-alex.bennee@linaro.org>

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target/riscv: support new isa extension detection devicetree properties

A few months ago I submitted a patch to various lists, deprecating
"riscv,isa" with a lengthy commit message [0] that is now c

target/riscv: support new isa extension detection devicetree properties

A few months ago I submitted a patch to various lists, deprecating
"riscv,isa" with a lengthy commit message [0] that is now commit
aeb71e42caae ("dt-bindings: riscv: deprecate riscv,isa") in the Linux
kernel tree. Primarily, the goal was to replace "riscv,isa" with a new
set of properties that allowed for strictly defining the meaning of
various extensions, where "riscv,isa" was tied to whatever definitions
inflicted upon us by the ISA manual, which have seen some variance over
time.

Two new properties were introduced: "riscv,isa-base" and
"riscv,isa-extensions". The former is a simple string to communicate the
base ISA implemented by a hart and the latter an array of strings used
to communicate the set of ISA extensions supported, per the definitions
of each substring in extensions.yaml [1]. A beneficial side effect was
also the ability to define vendor extensions in a more "official" way,
as the ISA manual and other RVI specifications only covered the format
for vendor extensions in the ISA string, but not the meaning of vendor
extensions, for obvious reasons.

Add support for setting these two new properties in the devicetrees for
the various devicetree platforms supported by QEMU for RISC-V. The Linux
kernel already supports parsing ISA extensions from these new
properties, and documenting them in the dt-binding is a requirement for
new extension detection being added to the kernel.

A side effect of the implementation is that the meaning for elements in
"riscv,isa" and in "riscv,isa-extensions" are now tied together as they
are constructed from the same source. The same applies to the ISA string
provided in ACPI tables, but there does not appear to be any strict
definitions of meanings in ACPI land either.

Link: https://lore.kernel.org/qemu-riscv/20230702-eats-scorebook-c951f170d29f@spud/ [0]
Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/riscv/extensions.yaml [1]
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Message-ID: <20240124-unvarying-foothold-9dde2aaf95d4@spud>
[ Changes by AF:
- Rebase on recent changes
]
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

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target/riscv: use misa_mxl_max to populate isa string rather than TARGET_LONG_BITS

A cpu may not have the same xlen as the compile time target, and
misa_mxl_max is the source of truth for what the h

target/riscv: use misa_mxl_max to populate isa string rather than TARGET_LONG_BITS

A cpu may not have the same xlen as the compile time target, and
misa_mxl_max is the source of truth for what the hart supports.

The conversion from misa_mxl_max to xlen already has one user, so
introduce a helper and use that to populate the isa string.

Link: https://lore.kernel.org/qemu-riscv/20240108-efa3f83dcd3997dc0af458d7@orel/
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Message-ID: <20240124-swear-monthly-56c281f809a6@spud>
[ Changes by AF:
- Convert to use RISCVCPUClass *mcc
]
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

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target/riscv: Move misa_mxl_max to class

misa_mxl_max is common for all instances of a RISC-V CPU class so they
are better put into class.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Re

target/riscv: Move misa_mxl_max to class

misa_mxl_max is common for all instances of a RISC-V CPU class so they
are better put into class.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20240203-riscv-v11-2-a23f4848a628@daynix.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

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