diff mbox series

[v4,08/14] none-machine: add 'ram-addr' property

Message ID 20220223090706.4888-9-damien.hedde@greensocs.com
State New
Headers show
Series Initial support for machine creation via QMP | expand

Commit Message

Damien Hedde Feb. 23, 2022, 9:07 a.m. UTC
Add the property to configure a the base address of the ram.
The default value remains zero.

This commit is needed to use the 'none' machine as a base, and
subsequently to dynamically populate it using qapi commands. Having
a non null 'ram' is really hard to workaround because of the actual
constraints on the generic loader: it prevents loading binaries
bigger than ram_size (with a null ram, we cannot load anything).
For now we need to be able to use the existing ram creation
feature of the none machine with a configurable base address.

Signed-off-by: Damien Hedde <damien.hedde@greensocs.com>
---
 hw/core/null-machine.c | 34 ++++++++++++++++++++++++++++++++--
 1 file changed, 32 insertions(+), 2 deletions(-)

Comments

Philippe Mathieu-Daudé March 3, 2022, 2:41 p.m. UTC | #1
On 23/2/22 10:07, Damien Hedde wrote:
> Add the property to configure a the base address of the ram.
> The default value remains zero.
> 
> This commit is needed to use the 'none' machine as a base, and
> subsequently to dynamically populate it using qapi commands. Having
> a non null 'ram' is really hard to workaround because of the actual
> constraints on the generic loader: it prevents loading binaries
> bigger than ram_size (with a null ram, we cannot load anything).
> For now we need to be able to use the existing ram creation
> feature of the none machine with a configurable base address.
> 
> Signed-off-by: Damien Hedde <damien.hedde@greensocs.com>
> ---
>   hw/core/null-machine.c | 34 ++++++++++++++++++++++++++++++++--
>   1 file changed, 32 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/core/null-machine.c b/hw/core/null-machine.c
> index 7eb258af07..5fd1cc0218 100644
> --- a/hw/core/null-machine.c
> +++ b/hw/core/null-machine.c
> @@ -16,9 +16,11 @@
>   #include "hw/boards.h"
>   #include "exec/address-spaces.h"
>   #include "hw/core/cpu.h"
> +#include "qapi/visitor.h"
>   
>   struct NoneMachineState {
>       MachineState parent;
> +    uint64_t ram_addr;
>   };
>   
>   #define TYPE_NONE_MACHINE MACHINE_TYPE_NAME("none")
> @@ -26,6 +28,7 @@ OBJECT_DECLARE_SIMPLE_TYPE(NoneMachineState, NONE_MACHINE)
>   
>   static void machine_none_init(MachineState *mch)
>   {
> +    NoneMachineState *nms = NONE_MACHINE(mch);
>       CPUState *cpu = NULL;
>   
>       /* Initialize CPU (if user asked for it) */
> @@ -37,9 +40,13 @@ static void machine_none_init(MachineState *mch)
>           }
>       }
>   
> -    /* RAM at address zero */
> +    /* RAM at configured address (default: 0) */
>       if (mch->ram) {
> -        memory_region_add_subregion(get_system_memory(), 0, mch->ram);
> +        memory_region_add_subregion(get_system_memory(), nms->ram_addr,
> +                                    mch->ram);
> +    } else if (nms->ram_addr) {
> +        error_report("'ram-addr' has been specified but the size is zero");

I'm not sure about this error message, IIUC we can get here if no ram
backend is provided, not if we have one zero-sized. Otherwise LGTM.

> +        exit(1);
>       }
Damien Hedde March 3, 2022, 4:19 p.m. UTC | #2
On 3/3/22 15:41, Philippe Mathieu-Daudé wrote:
> On 23/2/22 10:07, Damien Hedde wrote:
>> Add the property to configure a the base address of the ram.
>> The default value remains zero.
>>
>> This commit is needed to use the 'none' machine as a base, and
>> subsequently to dynamically populate it using qapi commands. Having
>> a non null 'ram' is really hard to workaround because of the actual
>> constraints on the generic loader: it prevents loading binaries
>> bigger than ram_size (with a null ram, we cannot load anything).
>> For now we need to be able to use the existing ram creation
>> feature of the none machine with a configurable base address.
>>
>> Signed-off-by: Damien Hedde <damien.hedde@greensocs.com>
>> ---
>>   hw/core/null-machine.c | 34 ++++++++++++++++++++++++++++++++--
>>   1 file changed, 32 insertions(+), 2 deletions(-)
>>
>> diff --git a/hw/core/null-machine.c b/hw/core/null-machine.c
>> index 7eb258af07..5fd1cc0218 100644
>> --- a/hw/core/null-machine.c
>> +++ b/hw/core/null-machine.c
>> @@ -16,9 +16,11 @@
>>   #include "hw/boards.h"
>>   #include "exec/address-spaces.h"
>>   #include "hw/core/cpu.h"
>> +#include "qapi/visitor.h"
>>   struct NoneMachineState {
>>       MachineState parent;
>> +    uint64_t ram_addr;
>>   };
>>   #define TYPE_NONE_MACHINE MACHINE_TYPE_NAME("none")
>> @@ -26,6 +28,7 @@ OBJECT_DECLARE_SIMPLE_TYPE(NoneMachineState, 
>> NONE_MACHINE)
>>   static void machine_none_init(MachineState *mch)
>>   {
>> +    NoneMachineState *nms = NONE_MACHINE(mch);
>>       CPUState *cpu = NULL;
>>       /* Initialize CPU (if user asked for it) */
>> @@ -37,9 +40,13 @@ static void machine_none_init(MachineState *mch)
>>           }
>>       }
>> -    /* RAM at address zero */
>> +    /* RAM at configured address (default: 0) */
>>       if (mch->ram) {
>> -        memory_region_add_subregion(get_system_memory(), 0, mch->ram);
>> +        memory_region_add_subregion(get_system_memory(), nms->ram_addr,
>> +                                    mch->ram);
>> +    } else if (nms->ram_addr) {
>> +        error_report("'ram-addr' has been specified but the size is 
>> zero");
> 
> I'm not sure about this error message, IIUC we can get here if no ram
> backend is provided, not if we have one zero-sized. Otherwise LGTM.

You're most probably right. Keeping the ram_size to 0 is just one way of 
getting here. I can replace the message by a more generic formulation
"'ram-addr' has been specified but the machine has no ram"
Jim Shu May 24, 2022, 8:09 p.m. UTC | #3
Tested-by: Jim Shu <jim.shu@sifive.com>

On Fri, Mar 4, 2022 at 12:36 AM Damien Hedde <damien.hedde@greensocs.com>
wrote:

>
>
> On 3/3/22 15:41, Philippe Mathieu-Daudé wrote:
> > On 23/2/22 10:07, Damien Hedde wrote:
> >> Add the property to configure a the base address of the ram.
> >> The default value remains zero.
> >>
> >> This commit is needed to use the 'none' machine as a base, and
> >> subsequently to dynamically populate it using qapi commands. Having
> >> a non null 'ram' is really hard to workaround because of the actual
> >> constraints on the generic loader: it prevents loading binaries
> >> bigger than ram_size (with a null ram, we cannot load anything).
> >> For now we need to be able to use the existing ram creation
> >> feature of the none machine with a configurable base address.
> >>
> >> Signed-off-by: Damien Hedde <damien.hedde@greensocs.com>
> >> ---
> >>   hw/core/null-machine.c | 34 ++++++++++++++++++++++++++++++++--
> >>   1 file changed, 32 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/hw/core/null-machine.c b/hw/core/null-machine.c
> >> index 7eb258af07..5fd1cc0218 100644
> >> --- a/hw/core/null-machine.c
> >> +++ b/hw/core/null-machine.c
> >> @@ -16,9 +16,11 @@
> >>   #include "hw/boards.h"
> >>   #include "exec/address-spaces.h"
> >>   #include "hw/core/cpu.h"
> >> +#include "qapi/visitor.h"
> >>   struct NoneMachineState {
> >>       MachineState parent;
> >> +    uint64_t ram_addr;
> >>   };
> >>   #define TYPE_NONE_MACHINE MACHINE_TYPE_NAME("none")
> >> @@ -26,6 +28,7 @@ OBJECT_DECLARE_SIMPLE_TYPE(NoneMachineState,
> >> NONE_MACHINE)
> >>   static void machine_none_init(MachineState *mch)
> >>   {
> >> +    NoneMachineState *nms = NONE_MACHINE(mch);
> >>       CPUState *cpu = NULL;
> >>       /* Initialize CPU (if user asked for it) */
> >> @@ -37,9 +40,13 @@ static void machine_none_init(MachineState *mch)
> >>           }
> >>       }
> >> -    /* RAM at address zero */
> >> +    /* RAM at configured address (default: 0) */
> >>       if (mch->ram) {
> >> -        memory_region_add_subregion(get_system_memory(), 0, mch->ram);
> >> +        memory_region_add_subregion(get_system_memory(), nms->ram_addr,
> >> +                                    mch->ram);
> >> +    } else if (nms->ram_addr) {
> >> +        error_report("'ram-addr' has been specified but the size is
> >> zero");
> >
> > I'm not sure about this error message, IIUC we can get here if no ram
> > backend is provided, not if we have one zero-sized. Otherwise LGTM.
>
> You're most probably right. Keeping the ram_size to 0 is just one way of
> getting here. I can replace the message by a more generic formulation
> "'ram-addr' has been specified but the machine has no ram"
>
>
>
diff mbox series

Patch

diff --git a/hw/core/null-machine.c b/hw/core/null-machine.c
index 7eb258af07..5fd1cc0218 100644
--- a/hw/core/null-machine.c
+++ b/hw/core/null-machine.c
@@ -16,9 +16,11 @@ 
 #include "hw/boards.h"
 #include "exec/address-spaces.h"
 #include "hw/core/cpu.h"
+#include "qapi/visitor.h"
 
 struct NoneMachineState {
     MachineState parent;
+    uint64_t ram_addr;
 };
 
 #define TYPE_NONE_MACHINE MACHINE_TYPE_NAME("none")
@@ -26,6 +28,7 @@  OBJECT_DECLARE_SIMPLE_TYPE(NoneMachineState, NONE_MACHINE)
 
 static void machine_none_init(MachineState *mch)
 {
+    NoneMachineState *nms = NONE_MACHINE(mch);
     CPUState *cpu = NULL;
 
     /* Initialize CPU (if user asked for it) */
@@ -37,9 +40,13 @@  static void machine_none_init(MachineState *mch)
         }
     }
 
-    /* RAM at address zero */
+    /* RAM at configured address (default: 0) */
     if (mch->ram) {
-        memory_region_add_subregion(get_system_memory(), 0, mch->ram);
+        memory_region_add_subregion(get_system_memory(), nms->ram_addr,
+                                    mch->ram);
+    } else if (nms->ram_addr) {
+        error_report("'ram-addr' has been specified but the size is zero");
+        exit(1);
     }
 
     if (mch->kernel_filename) {
@@ -49,6 +56,22 @@  static void machine_none_init(MachineState *mch)
     }
 }
 
+static void machine_none_get_ram_addr(Object *obj, Visitor *v, const char *name,
+                                      void *opaque, Error **errp)
+{
+    NoneMachineState *nms = NONE_MACHINE(obj);
+
+    visit_type_uint64(v, name, &nms->ram_addr, errp);
+}
+
+static void machine_none_set_ram_addr(Object *obj, Visitor *v, const char *name,
+                                      void *opaque, Error **errp)
+{
+    NoneMachineState *nms = NONE_MACHINE(obj);
+
+    visit_type_uint64(v, name, &nms->ram_addr, errp);
+}
+
 static void machine_none_class_init(ObjectClass *oc, void *data)
 {
     MachineClass *mc = MACHINE_CLASS(oc);
@@ -63,6 +86,13 @@  static void machine_none_class_init(ObjectClass *oc, void *data)
     mc->no_floppy = 1;
     mc->no_cdrom = 1;
     mc->no_sdcard = 1;
+
+    object_class_property_add(oc, "ram-addr", "int",
+        machine_none_get_ram_addr,
+        machine_none_set_ram_addr,
+        NULL, NULL);
+    object_class_property_set_description(oc, "ram-addr",
+        "Base address of the RAM (default is 0)");
 }
 
 static const TypeInfo none_machine_info = {