diff mbox series

[03/16] target/riscv/cpu.c: restrict 'mvendorid' value

Message ID 20230530194623.272652-4-dbarboza@ventanamicro.com (mailing list archive)
State New, archived
Headers show
Series target/riscv, KVM: fixes and enhancements | expand

Commit Message

Daniel Henrique Barboza May 30, 2023, 7:46 p.m. UTC
We're going to change the handling of mvendorid/marchid/mimpid by the
KVM driver. Since these are always present in all CPUs let's put the
same validation for everyone.

It doesn't make sense to allow 'mvendorid' to be different than it
is already set in named (vendor) CPUs. Generic (dynamic) CPUs can have
any 'mvendorid' they want.

Change 'mvendorid' to be a class property created via
'object_class_property_add', instead of using the DEFINE_PROP_UINT32()
macro. This allow us to define a custom setter for it that will verify,
for named CPUs, if mvendorid is different than it is already set by the
CPU. This is the error thrown for the 'veyron-v1' CPU if 'mvendorid' is
set to an invalid value:

$ qemu-system-riscv64 -M virt -nographic -cpu veyron-v1,mvendorid=2
qemu-system-riscv64: can't apply global veyron-v1-riscv-cpu.mvendorid=2:
    Unable to change veyron-v1-riscv-cpu mvendorid (0x61f)

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 target/riscv/cpu.c | 31 ++++++++++++++++++++++++++++++-
 1 file changed, 30 insertions(+), 1 deletion(-)

Comments

Andrew Jones June 6, 2023, 1:19 p.m. UTC | #1
On Tue, May 30, 2023 at 04:46:10PM -0300, Daniel Henrique Barboza wrote:
> We're going to change the handling of mvendorid/marchid/mimpid by the
> KVM driver. Since these are always present in all CPUs let's put the
> same validation for everyone.
> 
> It doesn't make sense to allow 'mvendorid' to be different than it
> is already set in named (vendor) CPUs. Generic (dynamic) CPUs can have
> any 'mvendorid' they want.
> 
> Change 'mvendorid' to be a class property created via
> 'object_class_property_add', instead of using the DEFINE_PROP_UINT32()
> macro. This allow us to define a custom setter for it that will verify,
> for named CPUs, if mvendorid is different than it is already set by the
> CPU. This is the error thrown for the 'veyron-v1' CPU if 'mvendorid' is
> set to an invalid value:
> 
> $ qemu-system-riscv64 -M virt -nographic -cpu veyron-v1,mvendorid=2
> qemu-system-riscv64: can't apply global veyron-v1-riscv-cpu.mvendorid=2:
>     Unable to change veyron-v1-riscv-cpu mvendorid (0x61f)
> 
> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> ---
>  target/riscv/cpu.c | 31 ++++++++++++++++++++++++++++++-
>  1 file changed, 30 insertions(+), 1 deletion(-)
> 
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index 72f5433776..bcd69bb032 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -1723,7 +1723,6 @@ static void riscv_cpu_add_user_properties(Object *obj)
>  static Property riscv_cpu_properties[] = {
>      DEFINE_PROP_BOOL("debug", RISCVCPU, cfg.debug, true),
>  
> -    DEFINE_PROP_UINT32("mvendorid", RISCVCPU, cfg.mvendorid, 0),
>      DEFINE_PROP_UINT64("marchid", RISCVCPU, cfg.marchid, RISCV_CPU_MARCHID),
>      DEFINE_PROP_UINT64("mimpid", RISCVCPU, cfg.mimpid, RISCV_CPU_MIMPID),
>  
> @@ -1810,6 +1809,32 @@ static const struct TCGCPUOps riscv_tcg_ops = {
>  #endif /* !CONFIG_USER_ONLY */
>  };
>  
> +static bool riscv_cpu_is_dynamic(Object *cpu_obj)
> +{
> +    return object_dynamic_cast(cpu_obj, TYPE_RISCV_DYNAMIC_CPU) != NULL;
> +}
> +
> +static void cpu_set_mvendorid(Object *obj, Visitor *v, const char *name,
> +                              void *opaque, Error **errp)
> +{
> +    bool dynamic_cpu = riscv_cpu_is_dynamic(obj);
> +    RISCVCPU *cpu = RISCV_CPU(obj);
> +    uint32_t prev_val = cpu->cfg.mvendorid;
> +    uint32_t value;
> +
> +    if (!visit_type_uint32(v, name, &value, errp)) {
> +        return;
> +    }
> +
> +    if (!dynamic_cpu && prev_val != value) {
> +        error_setg(errp, "Unable to change %s mvendorid (0x%x)",
> +                   object_get_typename(obj), prev_val);
> +        return;
> +    }
> +
> +    cpu->cfg.mvendorid = value;
> +}
> +
>  static void riscv_cpu_class_init(ObjectClass *c, void *data)
>  {
>      RISCVCPUClass *mcc = RISCV_CPU_CLASS(c);
> @@ -1841,6 +1866,10 @@ static void riscv_cpu_class_init(ObjectClass *c, void *data)
>      cc->gdb_get_dynamic_xml = riscv_gdb_get_dynamic_xml;
>      cc->tcg_ops = &riscv_tcg_ops;
>  
> +    object_class_property_add(c, "mvendorid", "uint32", NULL,
> +                              cpu_set_mvendorid,
> +                              NULL, NULL);
> +

Shouldn't we provide a get function as well?

>      device_class_set_props(dc, riscv_cpu_properties);
>  }
>  
> -- 
> 2.40.1
> 
> 

Otherwise,

Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Daniel Henrique Barboza June 6, 2023, 8:06 p.m. UTC | #2
On 6/6/23 10:19, Andrew Jones wrote:
> On Tue, May 30, 2023 at 04:46:10PM -0300, Daniel Henrique Barboza wrote:
>> We're going to change the handling of mvendorid/marchid/mimpid by the
>> KVM driver. Since these are always present in all CPUs let's put the
>> same validation for everyone.
>>
>> It doesn't make sense to allow 'mvendorid' to be different than it
>> is already set in named (vendor) CPUs. Generic (dynamic) CPUs can have
>> any 'mvendorid' they want.
>>
>> Change 'mvendorid' to be a class property created via
>> 'object_class_property_add', instead of using the DEFINE_PROP_UINT32()
>> macro. This allow us to define a custom setter for it that will verify,
>> for named CPUs, if mvendorid is different than it is already set by the
>> CPU. This is the error thrown for the 'veyron-v1' CPU if 'mvendorid' is
>> set to an invalid value:
>>
>> $ qemu-system-riscv64 -M virt -nographic -cpu veyron-v1,mvendorid=2
>> qemu-system-riscv64: can't apply global veyron-v1-riscv-cpu.mvendorid=2:
>>      Unable to change veyron-v1-riscv-cpu mvendorid (0x61f)
>>
>> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
>> ---
>>   target/riscv/cpu.c | 31 ++++++++++++++++++++++++++++++-
>>   1 file changed, 30 insertions(+), 1 deletion(-)
>>
>> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
>> index 72f5433776..bcd69bb032 100644
>> --- a/target/riscv/cpu.c
>> +++ b/target/riscv/cpu.c
>> @@ -1723,7 +1723,6 @@ static void riscv_cpu_add_user_properties(Object *obj)
>>   static Property riscv_cpu_properties[] = {
>>       DEFINE_PROP_BOOL("debug", RISCVCPU, cfg.debug, true),
>>   
>> -    DEFINE_PROP_UINT32("mvendorid", RISCVCPU, cfg.mvendorid, 0),
>>       DEFINE_PROP_UINT64("marchid", RISCVCPU, cfg.marchid, RISCV_CPU_MARCHID),
>>       DEFINE_PROP_UINT64("mimpid", RISCVCPU, cfg.mimpid, RISCV_CPU_MIMPID),
>>   
>> @@ -1810,6 +1809,32 @@ static const struct TCGCPUOps riscv_tcg_ops = {
>>   #endif /* !CONFIG_USER_ONLY */
>>   };
>>   
>> +static bool riscv_cpu_is_dynamic(Object *cpu_obj)
>> +{
>> +    return object_dynamic_cast(cpu_obj, TYPE_RISCV_DYNAMIC_CPU) != NULL;
>> +}
>> +
>> +static void cpu_set_mvendorid(Object *obj, Visitor *v, const char *name,
>> +                              void *opaque, Error **errp)
>> +{
>> +    bool dynamic_cpu = riscv_cpu_is_dynamic(obj);
>> +    RISCVCPU *cpu = RISCV_CPU(obj);
>> +    uint32_t prev_val = cpu->cfg.mvendorid;
>> +    uint32_t value;
>> +
>> +    if (!visit_type_uint32(v, name, &value, errp)) {
>> +        return;
>> +    }
>> +
>> +    if (!dynamic_cpu && prev_val != value) {
>> +        error_setg(errp, "Unable to change %s mvendorid (0x%x)",
>> +                   object_get_typename(obj), prev_val);
>> +        return;
>> +    }
>> +
>> +    cpu->cfg.mvendorid = value;
>> +}
>> +
>>   static void riscv_cpu_class_init(ObjectClass *c, void *data)
>>   {
>>       RISCVCPUClass *mcc = RISCV_CPU_CLASS(c);
>> @@ -1841,6 +1866,10 @@ static void riscv_cpu_class_init(ObjectClass *c, void *data)
>>       cc->gdb_get_dynamic_xml = riscv_gdb_get_dynamic_xml;
>>       cc->tcg_ops = &riscv_tcg_ops;
>>   
>> +    object_class_property_add(c, "mvendorid", "uint32", NULL,
>> +                              cpu_set_mvendorid,
>> +                              NULL, NULL);
>> +
> 
> Shouldn't we provide a get function as well?

We can. I refrain from adding a get() interface because I didn't add new code that
access mvendorid via object_property_get_uint(OBJECT(cpu), "mvendorid", errp). The
code that access this value uses cpu->cfg.mvendorid directly.

It would be interesting to add a get() interface if cpu->cfg.mvendorid was a value
that was read in a different manner that it's stored. It's not the case ATM, so
I only added the set() interface.


Thanks,


Daniel



> 
>>       device_class_set_props(dc, riscv_cpu_properties);
>>   }
>>   
>> -- 
>> 2.40.1
>>
>>
> 
> Otherwise,
> 
> Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Alistair Francis June 12, 2023, 3:56 a.m. UTC | #3
On Wed, May 31, 2023 at 5:49 AM Daniel Henrique Barboza
<dbarboza@ventanamicro.com> wrote:
>
> We're going to change the handling of mvendorid/marchid/mimpid by the
> KVM driver. Since these are always present in all CPUs let's put the
> same validation for everyone.
>
> It doesn't make sense to allow 'mvendorid' to be different than it
> is already set in named (vendor) CPUs. Generic (dynamic) CPUs can have
> any 'mvendorid' they want.
>
> Change 'mvendorid' to be a class property created via
> 'object_class_property_add', instead of using the DEFINE_PROP_UINT32()
> macro. This allow us to define a custom setter for it that will verify,
> for named CPUs, if mvendorid is different than it is already set by the
> CPU. This is the error thrown for the 'veyron-v1' CPU if 'mvendorid' is
> set to an invalid value:
>
> $ qemu-system-riscv64 -M virt -nographic -cpu veyron-v1,mvendorid=2
> qemu-system-riscv64: can't apply global veyron-v1-riscv-cpu.mvendorid=2:
>     Unable to change veyron-v1-riscv-cpu mvendorid (0x61f)

Is this something we want to enforce? What if someone wanted to test
using the veyron-v1 CPU but they wanted to change some properties. I
don't see an advantage in not letting them do that

Alistair

>
> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> ---
>  target/riscv/cpu.c | 31 ++++++++++++++++++++++++++++++-
>  1 file changed, 30 insertions(+), 1 deletion(-)
>
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index 72f5433776..bcd69bb032 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -1723,7 +1723,6 @@ static void riscv_cpu_add_user_properties(Object *obj)
>  static Property riscv_cpu_properties[] = {
>      DEFINE_PROP_BOOL("debug", RISCVCPU, cfg.debug, true),
>
> -    DEFINE_PROP_UINT32("mvendorid", RISCVCPU, cfg.mvendorid, 0),
>      DEFINE_PROP_UINT64("marchid", RISCVCPU, cfg.marchid, RISCV_CPU_MARCHID),
>      DEFINE_PROP_UINT64("mimpid", RISCVCPU, cfg.mimpid, RISCV_CPU_MIMPID),
>
> @@ -1810,6 +1809,32 @@ static const struct TCGCPUOps riscv_tcg_ops = {
>  #endif /* !CONFIG_USER_ONLY */
>  };
>
> +static bool riscv_cpu_is_dynamic(Object *cpu_obj)
> +{
> +    return object_dynamic_cast(cpu_obj, TYPE_RISCV_DYNAMIC_CPU) != NULL;
> +}
> +
> +static void cpu_set_mvendorid(Object *obj, Visitor *v, const char *name,
> +                              void *opaque, Error **errp)
> +{
> +    bool dynamic_cpu = riscv_cpu_is_dynamic(obj);
> +    RISCVCPU *cpu = RISCV_CPU(obj);
> +    uint32_t prev_val = cpu->cfg.mvendorid;
> +    uint32_t value;
> +
> +    if (!visit_type_uint32(v, name, &value, errp)) {
> +        return;
> +    }
> +
> +    if (!dynamic_cpu && prev_val != value) {
> +        error_setg(errp, "Unable to change %s mvendorid (0x%x)",
> +                   object_get_typename(obj), prev_val);
> +        return;
> +    }
> +
> +    cpu->cfg.mvendorid = value;
> +}
> +
>  static void riscv_cpu_class_init(ObjectClass *c, void *data)
>  {
>      RISCVCPUClass *mcc = RISCV_CPU_CLASS(c);
> @@ -1841,6 +1866,10 @@ static void riscv_cpu_class_init(ObjectClass *c, void *data)
>      cc->gdb_get_dynamic_xml = riscv_gdb_get_dynamic_xml;
>      cc->tcg_ops = &riscv_tcg_ops;
>
> +    object_class_property_add(c, "mvendorid", "uint32", NULL,
> +                              cpu_set_mvendorid,
> +                              NULL, NULL);
> +
>      device_class_set_props(dc, riscv_cpu_properties);
>  }
>
> --
> 2.40.1
>
>
Daniel Henrique Barboza June 12, 2023, 6:52 p.m. UTC | #4
On 6/12/23 00:56, Alistair Francis wrote:
> On Wed, May 31, 2023 at 5:49 AM Daniel Henrique Barboza
> <dbarboza@ventanamicro.com> wrote:
>>
>> We're going to change the handling of mvendorid/marchid/mimpid by the
>> KVM driver. Since these are always present in all CPUs let's put the
>> same validation for everyone.
>>
>> It doesn't make sense to allow 'mvendorid' to be different than it
>> is already set in named (vendor) CPUs. Generic (dynamic) CPUs can have
>> any 'mvendorid' they want.
>>
>> Change 'mvendorid' to be a class property created via
>> 'object_class_property_add', instead of using the DEFINE_PROP_UINT32()
>> macro. This allow us to define a custom setter for it that will verify,
>> for named CPUs, if mvendorid is different than it is already set by the
>> CPU. This is the error thrown for the 'veyron-v1' CPU if 'mvendorid' is
>> set to an invalid value:
>>
>> $ qemu-system-riscv64 -M virt -nographic -cpu veyron-v1,mvendorid=2
>> qemu-system-riscv64: can't apply global veyron-v1-riscv-cpu.mvendorid=2:
>>      Unable to change veyron-v1-riscv-cpu mvendorid (0x61f)
> 
> Is this something we want to enforce? What if someone wanted to test
> using the veyron-v1 CPU but they wanted to change some properties. I
> don't see an advantage in not letting them do that

The idea is to keep things simpler for us. As it is today we forbid users to
enable/disable extensions for vendor CPUs. Doing the same thing for
mvendorid/marchid/mimpid seems consistent with what we're already doing.

Also, guest software might rely on vendor IDs from the CPU to take certain
actions, and if the user is free to change the CPU ID from vendor CPUs the
software will misbehave and the user can claim "I created a veyron-v1 CPU and
the guest it's like like it's not". Allowing mvendorid and friends to be changed
doesn't do much for users (we forbid enabling/disabling extensions, so what's
to gain from changing machine IDs?) and it can be a potential source of bugs.



Thanks,


Daniel


> 
> Alistair
> 
>>
>> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
>> ---
>>   target/riscv/cpu.c | 31 ++++++++++++++++++++++++++++++-
>>   1 file changed, 30 insertions(+), 1 deletion(-)
>>
>> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
>> index 72f5433776..bcd69bb032 100644
>> --- a/target/riscv/cpu.c
>> +++ b/target/riscv/cpu.c
>> @@ -1723,7 +1723,6 @@ static void riscv_cpu_add_user_properties(Object *obj)
>>   static Property riscv_cpu_properties[] = {
>>       DEFINE_PROP_BOOL("debug", RISCVCPU, cfg.debug, true),
>>
>> -    DEFINE_PROP_UINT32("mvendorid", RISCVCPU, cfg.mvendorid, 0),
>>       DEFINE_PROP_UINT64("marchid", RISCVCPU, cfg.marchid, RISCV_CPU_MARCHID),
>>       DEFINE_PROP_UINT64("mimpid", RISCVCPU, cfg.mimpid, RISCV_CPU_MIMPID),
>>
>> @@ -1810,6 +1809,32 @@ static const struct TCGCPUOps riscv_tcg_ops = {
>>   #endif /* !CONFIG_USER_ONLY */
>>   };
>>
>> +static bool riscv_cpu_is_dynamic(Object *cpu_obj)
>> +{
>> +    return object_dynamic_cast(cpu_obj, TYPE_RISCV_DYNAMIC_CPU) != NULL;
>> +}
>> +
>> +static void cpu_set_mvendorid(Object *obj, Visitor *v, const char *name,
>> +                              void *opaque, Error **errp)
>> +{
>> +    bool dynamic_cpu = riscv_cpu_is_dynamic(obj);
>> +    RISCVCPU *cpu = RISCV_CPU(obj);
>> +    uint32_t prev_val = cpu->cfg.mvendorid;
>> +    uint32_t value;
>> +
>> +    if (!visit_type_uint32(v, name, &value, errp)) {
>> +        return;
>> +    }
>> +
>> +    if (!dynamic_cpu && prev_val != value) {
>> +        error_setg(errp, "Unable to change %s mvendorid (0x%x)",
>> +                   object_get_typename(obj), prev_val);
>> +        return;
>> +    }
>> +
>> +    cpu->cfg.mvendorid = value;
>> +}
>> +
>>   static void riscv_cpu_class_init(ObjectClass *c, void *data)
>>   {
>>       RISCVCPUClass *mcc = RISCV_CPU_CLASS(c);
>> @@ -1841,6 +1866,10 @@ static void riscv_cpu_class_init(ObjectClass *c, void *data)
>>       cc->gdb_get_dynamic_xml = riscv_gdb_get_dynamic_xml;
>>       cc->tcg_ops = &riscv_tcg_ops;
>>
>> +    object_class_property_add(c, "mvendorid", "uint32", NULL,
>> +                              cpu_set_mvendorid,
>> +                              NULL, NULL);
>> +
>>       device_class_set_props(dc, riscv_cpu_properties);
>>   }
>>
>> --
>> 2.40.1
>>
>>
Alistair Francis June 13, 2023, 6:46 a.m. UTC | #5
On Tue, Jun 13, 2023 at 4:52 AM Daniel Henrique Barboza
<dbarboza@ventanamicro.com> wrote:
>
>
>
> On 6/12/23 00:56, Alistair Francis wrote:
> > On Wed, May 31, 2023 at 5:49 AM Daniel Henrique Barboza
> > <dbarboza@ventanamicro.com> wrote:
> >>
> >> We're going to change the handling of mvendorid/marchid/mimpid by the
> >> KVM driver. Since these are always present in all CPUs let's put the
> >> same validation for everyone.
> >>
> >> It doesn't make sense to allow 'mvendorid' to be different than it
> >> is already set in named (vendor) CPUs. Generic (dynamic) CPUs can have
> >> any 'mvendorid' they want.
> >>
> >> Change 'mvendorid' to be a class property created via
> >> 'object_class_property_add', instead of using the DEFINE_PROP_UINT32()
> >> macro. This allow us to define a custom setter for it that will verify,
> >> for named CPUs, if mvendorid is different than it is already set by the
> >> CPU. This is the error thrown for the 'veyron-v1' CPU if 'mvendorid' is
> >> set to an invalid value:
> >>
> >> $ qemu-system-riscv64 -M virt -nographic -cpu veyron-v1,mvendorid=2
> >> qemu-system-riscv64: can't apply global veyron-v1-riscv-cpu.mvendorid=2:
> >>      Unable to change veyron-v1-riscv-cpu mvendorid (0x61f)
> >
> > Is this something we want to enforce? What if someone wanted to test
> > using the veyron-v1 CPU but they wanted to change some properties. I
> > don't see an advantage in not letting them do that
>
> The idea is to keep things simpler for us. As it is today we forbid users to
> enable/disable extensions for vendor CPUs. Doing the same thing for
> mvendorid/marchid/mimpid seems consistent with what we're already doing.
>
> Also, guest software might rely on vendor IDs from the CPU to take certain
> actions, and if the user is free to change the CPU ID from vendor CPUs the
> software will misbehave and the user can claim "I created a veyron-v1 CPU and
> the guest it's like like it's not". Allowing mvendorid and friends to be changed
> doesn't do much for users (we forbid enabling/disabling extensions, so what's
> to gain from changing machine IDs?) and it can be a potential source of bugs.

Fair points. Ok, fine with me then :)

Alistair

>
>
>
> Thanks,
>
>
> Daniel
>
>
> >
> > Alistair
> >
> >>
> >> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> >> ---
> >>   target/riscv/cpu.c | 31 ++++++++++++++++++++++++++++++-
> >>   1 file changed, 30 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> >> index 72f5433776..bcd69bb032 100644
> >> --- a/target/riscv/cpu.c
> >> +++ b/target/riscv/cpu.c
> >> @@ -1723,7 +1723,6 @@ static void riscv_cpu_add_user_properties(Object *obj)
> >>   static Property riscv_cpu_properties[] = {
> >>       DEFINE_PROP_BOOL("debug", RISCVCPU, cfg.debug, true),
> >>
> >> -    DEFINE_PROP_UINT32("mvendorid", RISCVCPU, cfg.mvendorid, 0),
> >>       DEFINE_PROP_UINT64("marchid", RISCVCPU, cfg.marchid, RISCV_CPU_MARCHID),
> >>       DEFINE_PROP_UINT64("mimpid", RISCVCPU, cfg.mimpid, RISCV_CPU_MIMPID),
> >>
> >> @@ -1810,6 +1809,32 @@ static const struct TCGCPUOps riscv_tcg_ops = {
> >>   #endif /* !CONFIG_USER_ONLY */
> >>   };
> >>
> >> +static bool riscv_cpu_is_dynamic(Object *cpu_obj)
> >> +{
> >> +    return object_dynamic_cast(cpu_obj, TYPE_RISCV_DYNAMIC_CPU) != NULL;
> >> +}
> >> +
> >> +static void cpu_set_mvendorid(Object *obj, Visitor *v, const char *name,
> >> +                              void *opaque, Error **errp)
> >> +{
> >> +    bool dynamic_cpu = riscv_cpu_is_dynamic(obj);
> >> +    RISCVCPU *cpu = RISCV_CPU(obj);
> >> +    uint32_t prev_val = cpu->cfg.mvendorid;
> >> +    uint32_t value;
> >> +
> >> +    if (!visit_type_uint32(v, name, &value, errp)) {
> >> +        return;
> >> +    }
> >> +
> >> +    if (!dynamic_cpu && prev_val != value) {
> >> +        error_setg(errp, "Unable to change %s mvendorid (0x%x)",
> >> +                   object_get_typename(obj), prev_val);
> >> +        return;
> >> +    }
> >> +
> >> +    cpu->cfg.mvendorid = value;
> >> +}
> >> +
> >>   static void riscv_cpu_class_init(ObjectClass *c, void *data)
> >>   {
> >>       RISCVCPUClass *mcc = RISCV_CPU_CLASS(c);
> >> @@ -1841,6 +1866,10 @@ static void riscv_cpu_class_init(ObjectClass *c, void *data)
> >>       cc->gdb_get_dynamic_xml = riscv_gdb_get_dynamic_xml;
> >>       cc->tcg_ops = &riscv_tcg_ops;
> >>
> >> +    object_class_property_add(c, "mvendorid", "uint32", NULL,
> >> +                              cpu_set_mvendorid,
> >> +                              NULL, NULL);
> >> +
> >>       device_class_set_props(dc, riscv_cpu_properties);
> >>   }
> >>
> >> --
> >> 2.40.1
> >>
> >>
diff mbox series

Patch

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 72f5433776..bcd69bb032 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -1723,7 +1723,6 @@  static void riscv_cpu_add_user_properties(Object *obj)
 static Property riscv_cpu_properties[] = {
     DEFINE_PROP_BOOL("debug", RISCVCPU, cfg.debug, true),
 
-    DEFINE_PROP_UINT32("mvendorid", RISCVCPU, cfg.mvendorid, 0),
     DEFINE_PROP_UINT64("marchid", RISCVCPU, cfg.marchid, RISCV_CPU_MARCHID),
     DEFINE_PROP_UINT64("mimpid", RISCVCPU, cfg.mimpid, RISCV_CPU_MIMPID),
 
@@ -1810,6 +1809,32 @@  static const struct TCGCPUOps riscv_tcg_ops = {
 #endif /* !CONFIG_USER_ONLY */
 };
 
+static bool riscv_cpu_is_dynamic(Object *cpu_obj)
+{
+    return object_dynamic_cast(cpu_obj, TYPE_RISCV_DYNAMIC_CPU) != NULL;
+}
+
+static void cpu_set_mvendorid(Object *obj, Visitor *v, const char *name,
+                              void *opaque, Error **errp)
+{
+    bool dynamic_cpu = riscv_cpu_is_dynamic(obj);
+    RISCVCPU *cpu = RISCV_CPU(obj);
+    uint32_t prev_val = cpu->cfg.mvendorid;
+    uint32_t value;
+
+    if (!visit_type_uint32(v, name, &value, errp)) {
+        return;
+    }
+
+    if (!dynamic_cpu && prev_val != value) {
+        error_setg(errp, "Unable to change %s mvendorid (0x%x)",
+                   object_get_typename(obj), prev_val);
+        return;
+    }
+
+    cpu->cfg.mvendorid = value;
+}
+
 static void riscv_cpu_class_init(ObjectClass *c, void *data)
 {
     RISCVCPUClass *mcc = RISCV_CPU_CLASS(c);
@@ -1841,6 +1866,10 @@  static void riscv_cpu_class_init(ObjectClass *c, void *data)
     cc->gdb_get_dynamic_xml = riscv_gdb_get_dynamic_xml;
     cc->tcg_ops = &riscv_tcg_ops;
 
+    object_class_property_add(c, "mvendorid", "uint32", NULL,
+                              cpu_set_mvendorid,
+                              NULL, NULL);
+
     device_class_set_props(dc, riscv_cpu_properties);
 }