There are features in the forthcoming patches which are dependent on
MPU. For eg fixed start address.
Also, some of the Xen features (eg STATIC_MEMORY) will be selected
by the MPU configuration.
Thus, this patch introduces a choice between MMU and MPU for the type
of memory management system. By default, MMU is selected.
All the current platforms are now made dependent on MMU.
Signed-off-by: Ayan Kumar Halder <ayan.kumar.halder@amd.com>
---
xen/arch/arm/Kconfig | 17 ++++++++++++++++-
xen/arch/arm/platforms/Kconfig | 2 +-
2 files changed, 17 insertions(+), 2 deletions(-)
diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig
index 323c967361..686948cefd 100644
--- a/xen/arch/arm/Kconfig
+++ b/xen/arch/arm/Kconfig
@@ -58,10 +58,25 @@ config PADDR_BITS
default 40 if ARM_PA_BITS_40
default 48 if ARM_64
+choice
+ prompt "Memory management system"
+ default MMU if ARM
+ help
+ User can choose between the different forms of memory management system.
+ Most of the Arm based systems support MMU.
+
config MMU
- def_bool y
+ bool "MMU"
select HAS_PMAP
select HAS_VMAP
+ help
+ Memory management unit is supported on most Arm based systems.
+
+config MPU
+ bool "MPU"
+ help
+ Memory protection unit is supported on some Cortex-R systems.
+endchoice
source "arch/Kconfig"
diff --git a/xen/arch/arm/platforms/Kconfig b/xen/arch/arm/platforms/Kconfig
index 76f7e76b1b..02322c259c 100644
--- a/xen/arch/arm/platforms/Kconfig
+++ b/xen/arch/arm/platforms/Kconfig
@@ -1,5 +1,5 @@
choice
- prompt "Platform Support"
+ prompt "Platform Support" if MMU
default ALL_PLAT
help
Choose which hardware platform to enable in Xen.
--
2.25.1Hi, On 23/08/2024 17:31, Ayan Kumar Halder wrote: > There are features in the forthcoming patches which are dependent on > MPU. For eg fixed start address. > Also, some of the Xen features (eg STATIC_MEMORY) will be selected > by the MPU configuration. > > Thus, this patch introduces a choice between MMU and MPU for the type > of memory management system. By default, MMU is selected. > All the current platforms are now made dependent on MMU. > > Signed-off-by: Ayan Kumar Halder <ayan.kumar.halder@amd.com> > --- > xen/arch/arm/Kconfig | 17 ++++++++++++++++- > xen/arch/arm/platforms/Kconfig | 2 +- > 2 files changed, 17 insertions(+), 2 deletions(-) > > diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig > index 323c967361..686948cefd 100644 > --- a/xen/arch/arm/Kconfig > +++ b/xen/arch/arm/Kconfig > @@ -58,10 +58,25 @@ config PADDR_BITS > default 40 if ARM_PA_BITS_40 > default 48 if ARM_64 > > +choice > + prompt "Memory management system" > + default MMU if ARM > + help > + User can choose between the different forms of memory management system. > + Most of the Arm based systems support MMU. I feel this is quite subjective. So I would drop it. > + > config MMU > - def_bool y > + bool "MMU" > select HAS_PMAP > select HAS_VMAP > + help > + Memory management unit is supported on most Arm based systems. For this case, I would write "Select it you are plan to run Xen on Armv7-A or Armv8-A". > + > +config MPU > + bool "MPU" I think it should be gated by UNSUPPORTED. SUPPORT.md also needs to be updated. > + help > + Memory protection unit is supported on some Cortex-R systems. Why do you make this specific to Cortex-R? Shouldn't this instead be Armv8-R? > +endchoice > > source "arch/Kconfig" > > diff --git a/xen/arch/arm/platforms/Kconfig b/xen/arch/arm/platforms/Kconfig > index 76f7e76b1b..02322c259c 100644 > --- a/xen/arch/arm/platforms/Kconfig > +++ b/xen/arch/arm/platforms/Kconfig > @@ -1,5 +1,5 @@ > choice > - prompt "Platform Support" > + prompt "Platform Support" if MMU > default ALL_PLAT > help > Choose which hardware platform to enable in Xen. -- Julien Grall
On 27/08/2024 11:37, Julien Grall wrote: > Hi, Hi Julien, > > On 23/08/2024 17:31, Ayan Kumar Halder wrote: >> There are features in the forthcoming patches which are dependent on >> MPU. For eg fixed start address. >> Also, some of the Xen features (eg STATIC_MEMORY) will be selected >> by the MPU configuration. >> >> Thus, this patch introduces a choice between MMU and MPU for the type >> of memory management system. By default, MMU is selected. >> All the current platforms are now made dependent on MMU. >> >> Signed-off-by: Ayan Kumar Halder <ayan.kumar.halder@amd.com> >> --- >> xen/arch/arm/Kconfig | 17 ++++++++++++++++- >> xen/arch/arm/platforms/Kconfig | 2 +- >> 2 files changed, 17 insertions(+), 2 deletions(-) >> >> diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig >> index 323c967361..686948cefd 100644 >> --- a/xen/arch/arm/Kconfig >> +++ b/xen/arch/arm/Kconfig >> @@ -58,10 +58,25 @@ config PADDR_BITS >> default 40 if ARM_PA_BITS_40 >> default 48 if ARM_64 >> +choice >> + prompt "Memory management system" >> + default MMU if ARM >> + help >> + User can choose between the different forms of memory >> management system. >> + Most of the Arm based systems support MMU. > > I feel this is quite subjective. So I would drop it. Agreed. > >> + >> config MMU >> - def_bool y >> + bool "MMU" >> select HAS_PMAP >> select HAS_VMAP >> + help >> + Memory management unit is supported on most Arm based systems. > > For this case, I would write "Select it you are plan to run Xen on > Armv7-A or Armv8-A". Ack. > > >> + >> +config MPU >> + bool "MPU" > > I think it should be gated by UNSUPPORTED. SUPPORT.md also needs to be > updated. Ack. > >> + help >> + Memory protection unit is supported on some Cortex-R systems. > > Why do you make this specific to Cortex-R? Shouldn't this instead be > Armv8-R? Yes, you are correct. It should be Armv8-R. Otherwise, someone might think it is applicable for Cortex-R5, R7, etc. - Ayan
Hi, On 28/08/2024 15:44, Ayan Kumar Halder wrote: > > On 27/08/2024 11:37, Julien Grall wrote: >> Hi, > Hi Julien, >> >> On 23/08/2024 17:31, Ayan Kumar Halder wrote: >>> There are features in the forthcoming patches which are dependent on >>> MPU. For eg fixed start address. >>> Also, some of the Xen features (eg STATIC_MEMORY) will be selected >>> by the MPU configuration. >>> >>> Thus, this patch introduces a choice between MMU and MPU for the type >>> of memory management system. By default, MMU is selected. >>> All the current platforms are now made dependent on MMU. >>> >>> Signed-off-by: Ayan Kumar Halder <ayan.kumar.halder@amd.com> >>> --- >>> xen/arch/arm/Kconfig | 17 ++++++++++++++++- >>> xen/arch/arm/platforms/Kconfig | 2 +- >>> 2 files changed, 17 insertions(+), 2 deletions(-) >>> >>> diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig >>> index 323c967361..686948cefd 100644 >>> --- a/xen/arch/arm/Kconfig >>> +++ b/xen/arch/arm/Kconfig >>> @@ -58,10 +58,25 @@ config PADDR_BITS >>> default 40 if ARM_PA_BITS_40 >>> default 48 if ARM_64 >>> +choice >>> + prompt "Memory management system" >>> + default MMU if ARM >>> + help >>> + User can choose between the different forms of memory >>> management system. >>> + Most of the Arm based systems support MMU. >> >> I feel this is quite subjective. So I would drop it. > Agreed. >> >>> + >>> config MMU >>> - def_bool y >>> + bool "MMU" >>> select HAS_PMAP >>> select HAS_VMAP >>> + help >>> + Memory management unit is supported on most Arm based systems. >> >> For this case, I would write "Select it you are plan to run Xen on >> Armv7-A or Armv8-A". > Ack. Actually, thinking a bit more. We should be able to run Xen on Armv9. So maybe it would be beter to write: "Select it if you plan to run Xen on A-profile Armv7+". Cheers, -- Julien Grall
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