- Extended p2m_type_t with additional types: p2m_ram_ro, p2m_mmio_direct_dev,
p2m_grant_map_{rw,ro}.
- Added macros to classify memory types: P2M_RAM_TYPES, P2M_GRANT_TYPES.
- Introduced helper predicates: p2m_is_ram(), p2m_is_any_ram().
Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
---
Changes in V2:
- Drop stuff connected to foreign mapping as it isn't necessary for RISC-V
right now.
---
xen/arch/riscv/include/asm/p2m.h | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/xen/arch/riscv/include/asm/p2m.h b/xen/arch/riscv/include/asm/p2m.h
index a31b05bd50..0c05b58992 100644
--- a/xen/arch/riscv/include/asm/p2m.h
+++ b/xen/arch/riscv/include/asm/p2m.h
@@ -61,8 +61,28 @@ struct p2m_domain {
typedef enum {
p2m_invalid = 0, /* Nothing mapped here */
p2m_ram_rw, /* Normal read/write domain RAM */
+ p2m_ram_ro, /* Read-only; writes are silently dropped */
+ p2m_mmio_direct_dev,/* Read/write mapping of genuine Device MMIO area */
+ p2m_grant_map_rw, /* Read/write grant mapping */
+ p2m_grant_map_ro, /* Read-only grant mapping */
} p2m_type_t;
+/* We use bitmaps and mask to handle groups of types */
+#define p2m_to_mask(t_) BIT(t_, UL)
+
+/* RAM types, which map to real machine frames */
+#define P2M_RAM_TYPES (p2m_to_mask(p2m_ram_rw) | \
+ p2m_to_mask(p2m_ram_ro))
+
+/* Grant mapping types, which map to a real frame in another VM */
+#define P2M_GRANT_TYPES (p2m_to_mask(p2m_grant_map_rw) | \
+ p2m_to_mask(p2m_grant_map_ro))
+
+/* Useful predicates */
+#define p2m_is_ram(t_) (p2m_to_mask(t_) & P2M_RAM_TYPES)
+#define p2m_is_any_ram(t_) (p2m_to_mask(t_) & \
+ (P2M_RAM_TYPES | P2M_GRANT_TYPES))
+
#include <xen/p2m-common.h>
static inline int get_page_and_type(struct page_info *page,
--
2.49.0On 10.06.2025 15:05, Oleksii Kurochko wrote:
> --- a/xen/arch/riscv/include/asm/p2m.h
> +++ b/xen/arch/riscv/include/asm/p2m.h
> @@ -61,8 +61,28 @@ struct p2m_domain {
> typedef enum {
> p2m_invalid = 0, /* Nothing mapped here */
> p2m_ram_rw, /* Normal read/write domain RAM */
> + p2m_ram_ro, /* Read-only; writes are silently dropped */
As indicated before - this type should be added when the special handling that
it requires is also introduced.
> + p2m_mmio_direct_dev,/* Read/write mapping of genuine Device MMIO area */
What's the _dev suffix indicating here?
Jan
On 6/26/25 4:59 PM, Jan Beulich wrote:
> On 10.06.2025 15:05, Oleksii Kurochko wrote:
>> --- a/xen/arch/riscv/include/asm/p2m.h
>> +++ b/xen/arch/riscv/include/asm/p2m.h
>> @@ -61,8 +61,28 @@ struct p2m_domain {
>> typedef enum {
>> p2m_invalid = 0, /* Nothing mapped here */
>> p2m_ram_rw, /* Normal read/write domain RAM */
>> + p2m_ram_ro, /* Read-only; writes are silently dropped */
> As indicated before - this type should be added when the special handling that
> it requires is also introduced.
Perhaps, I missed that. I will drop this type for now.
>
>> + p2m_mmio_direct_dev,/* Read/write mapping of genuine Device MMIO area */
> What's the _dev suffix indicating here?
It indicates that it is device memory, probably, it isn't so necessary in case of RISC-V as
spec doesn't use such terminology. In RISC-V there is only available IO, NC. And we are
|using PTE_PBMT_IO for |p2m_mmio_direct_dev.
Maybe it would be better just to rename s/p2m_mmio_direct_dev/p2m_mmio_direct_io.
~ Oleksii
On 30.06.2025 16:33, Oleksii Kurochko wrote:
> On 6/26/25 4:59 PM, Jan Beulich wrote:
>> On 10.06.2025 15:05, Oleksii Kurochko wrote:
>>> --- a/xen/arch/riscv/include/asm/p2m.h
>>> +++ b/xen/arch/riscv/include/asm/p2m.h
>>> @@ -61,8 +61,28 @@ struct p2m_domain {
>>> typedef enum {
>>> p2m_invalid = 0, /* Nothing mapped here */
>>> p2m_ram_rw, /* Normal read/write domain RAM */
>>> + p2m_ram_ro, /* Read-only; writes are silently dropped */
>> As indicated before - this type should be added when the special handling that
>> it requires is also introduced.
>
> Perhaps, I missed that. I will drop this type for now.
>
>>
>>> + p2m_mmio_direct_dev,/* Read/write mapping of genuine Device MMIO area */
>> What's the _dev suffix indicating here?
>
> It indicates that it is device memory, probably, it isn't so necessary in case of RISC-V as
> spec doesn't use such terminology. In RISC-V there is only available IO, NC. And we are
> |using PTE_PBMT_IO for |p2m_mmio_direct_dev.
>
> Maybe it would be better just to rename s/p2m_mmio_direct_dev/p2m_mmio_direct_io.
And what would the _io suffix indicate, beyond what "mmio" already indicates?
Jan
On 6/30/25 4:42 PM, Jan Beulich wrote:
> On 30.06.2025 16:33, Oleksii Kurochko wrote:
>> On 6/26/25 4:59 PM, Jan Beulich wrote:
>>> On 10.06.2025 15:05, Oleksii Kurochko wrote:
>>>> --- a/xen/arch/riscv/include/asm/p2m.h
>>>> +++ b/xen/arch/riscv/include/asm/p2m.h
>>>> @@ -61,8 +61,28 @@ struct p2m_domain {
>>>> typedef enum {
>>>> p2m_invalid = 0, /* Nothing mapped here */
>>>> p2m_ram_rw, /* Normal read/write domain RAM */
>>>> + p2m_ram_ro, /* Read-only; writes are silently dropped */
>>> As indicated before - this type should be added when the special handling that
>>> it requires is also introduced.
>> Perhaps, I missed that. I will drop this type for now.
>>
>>>> + p2m_mmio_direct_dev,/* Read/write mapping of genuine Device MMIO area */
>>> What's the _dev suffix indicating here?
>> It indicates that it is device memory, probably, it isn't so necessary in case of RISC-V as
>> spec doesn't use such terminology. In RISC-V there is only available IO, NC. And we are
>> |using PTE_PBMT_IO for |p2m_mmio_direct_dev.
>>
>> Maybe it would be better just to rename s/p2m_mmio_direct_dev/p2m_mmio_direct_io.
> And what would the _io suffix indicate, beyond what "mmio" already indicates?
Just that PBMT_IO will be used for device memory and not PBMT_NC.
~ Oleksii
On 30.06.2025 17:13, Oleksii Kurochko wrote:
>
> On 6/30/25 4:42 PM, Jan Beulich wrote:
>> On 30.06.2025 16:33, Oleksii Kurochko wrote:
>>> On 6/26/25 4:59 PM, Jan Beulich wrote:
>>>> On 10.06.2025 15:05, Oleksii Kurochko wrote:
>>>>> --- a/xen/arch/riscv/include/asm/p2m.h
>>>>> +++ b/xen/arch/riscv/include/asm/p2m.h
>>>>> @@ -61,8 +61,28 @@ struct p2m_domain {
>>>>> typedef enum {
>>>>> p2m_invalid = 0, /* Nothing mapped here */
>>>>> p2m_ram_rw, /* Normal read/write domain RAM */
>>>>> + p2m_ram_ro, /* Read-only; writes are silently dropped */
>>>> As indicated before - this type should be added when the special handling that
>>>> it requires is also introduced.
>>> Perhaps, I missed that. I will drop this type for now.
>>>
>>>>> + p2m_mmio_direct_dev,/* Read/write mapping of genuine Device MMIO area */
>>>> What's the _dev suffix indicating here?
>>> It indicates that it is device memory, probably, it isn't so necessary in case of RISC-V as
>>> spec doesn't use such terminology. In RISC-V there is only available IO, NC. And we are
>>> |using PTE_PBMT_IO for |p2m_mmio_direct_dev.
>>>
>>> Maybe it would be better just to rename s/p2m_mmio_direct_dev/p2m_mmio_direct_io.
>> And what would the _io suffix indicate, beyond what "mmio" already indicates?
>
> Just that PBMT_IO will be used for device memory and not PBMT_NC.
And will there (later) also be a p2m_mmio_direct_nc type? If so, I can see the point
of the suffix.
Jan
On 6/30/25 4:33 PM, Oleksii Kurochko wrote:
>
>
> On 6/26/25 4:59 PM, Jan Beulich wrote:
>> On 10.06.2025 15:05, Oleksii Kurochko wrote:
>>> --- a/xen/arch/riscv/include/asm/p2m.h
>>> +++ b/xen/arch/riscv/include/asm/p2m.h
>>> @@ -61,8 +61,28 @@ struct p2m_domain {
>>> typedef enum {
>>> p2m_invalid = 0, /* Nothing mapped here */
>>> p2m_ram_rw, /* Normal read/write domain RAM */
>>> + p2m_ram_ro, /* Read-only; writes are silently dropped */
>> As indicated before - this type should be added when the special handling that
>> it requires is also introduced.
> Perhaps, I missed that. I will drop this type for now.
>
>>> + p2m_mmio_direct_dev,/* Read/write mapping of genuine Device MMIO area */
>> What's the _dev suffix indicating here?
> It indicates that it is device memory, probably, it isn't so necessary in case of RISC-V as
> spec doesn't use such terminology. In RISC-V there is only available IO, NC. And we are
> |using PTE_PBMT_IO for |p2m_mmio_direct_dev.
>
> Maybe it would be better just to rename s/p2m_mmio_direct_dev/p2m_mmio_direct_io.
I forgot that p2m_mmio_direct_dev is used by common code for dom0less code (handle_passthrough_prop())
~ Oleksii
On 30.06.2025 16:38, Oleksii Kurochko wrote:
> On 6/30/25 4:33 PM, Oleksii Kurochko wrote:
>> On 6/26/25 4:59 PM, Jan Beulich wrote:
>>> On 10.06.2025 15:05, Oleksii Kurochko wrote:
>>>> --- a/xen/arch/riscv/include/asm/p2m.h
>>>> +++ b/xen/arch/riscv/include/asm/p2m.h
>>>> @@ -61,8 +61,28 @@ struct p2m_domain {
>>>> typedef enum {
>>>> p2m_invalid = 0, /* Nothing mapped here */
>>>> p2m_ram_rw, /* Normal read/write domain RAM */
>>>> + p2m_ram_ro, /* Read-only; writes are silently dropped */
>>> As indicated before - this type should be added when the special handling that
>>> it requires is also introduced.
>> Perhaps, I missed that. I will drop this type for now.
>>
>>>> + p2m_mmio_direct_dev,/* Read/write mapping of genuine Device MMIO area */
>>> What's the _dev suffix indicating here?
>> It indicates that it is device memory, probably, it isn't so necessary in case of RISC-V as
>> spec doesn't use such terminology. In RISC-V there is only available IO, NC. And we are
>> |using PTE_PBMT_IO for |p2m_mmio_direct_dev.
>>
>> Maybe it would be better just to rename s/p2m_mmio_direct_dev/p2m_mmio_direct_io.
>
> I forgot that p2m_mmio_direct_dev is used by common code for dom0less code (handle_passthrough_prop())
That'll want abstracting out, I think. I don't view it as helpful to clutter
RISC-V (and later perhaps also PPC) with Arm-specific terminology.
Jan
On 6/30/25 4:45 PM, Jan Beulich wrote:
> On 30.06.2025 16:38, Oleksii Kurochko wrote:
>> On 6/30/25 4:33 PM, Oleksii Kurochko wrote:
>>> On 6/26/25 4:59 PM, Jan Beulich wrote:
>>>> On 10.06.2025 15:05, Oleksii Kurochko wrote:
>>>>> --- a/xen/arch/riscv/include/asm/p2m.h
>>>>> +++ b/xen/arch/riscv/include/asm/p2m.h
>>>>> @@ -61,8 +61,28 @@ struct p2m_domain {
>>>>> typedef enum {
>>>>> p2m_invalid = 0, /* Nothing mapped here */
>>>>> p2m_ram_rw, /* Normal read/write domain RAM */
>>>>> + p2m_ram_ro, /* Read-only; writes are silently dropped */
>>>> As indicated before - this type should be added when the special handling that
>>>> it requires is also introduced.
>>> Perhaps, I missed that. I will drop this type for now.
>>>
>>>>> + p2m_mmio_direct_dev,/* Read/write mapping of genuine Device MMIO area */
>>>> What's the _dev suffix indicating here?
>>> It indicates that it is device memory, probably, it isn't so necessary in case of RISC-V as
>>> spec doesn't use such terminology. In RISC-V there is only available IO, NC. And we are
>>> |using PTE_PBMT_IO for |p2m_mmio_direct_dev.
>>>
>>> Maybe it would be better just to rename s/p2m_mmio_direct_dev/p2m_mmio_direct_io.
>> I forgot that p2m_mmio_direct_dev is used by common code for dom0less code (handle_passthrough_prop())
> That'll want abstracting out, I think. I don't view it as helpful to clutter
> RISC-V (and later perhaps also PPC) with Arm-specific terminology.
Would it be better then just rename it to p2m_device? Then it won't clear for Arm which type of MMIO p2m's
types is used as Arm has there MMIO types: *_dev, *_nc, *_c.
As an option (which I don't really like) it could be "#define p2m_mmio_direct_dev ARCH_specific_name" in
asm/p2m.h to not touch common code.
~ Oleksii
On 30.06.2025 17:27, Oleksii Kurochko wrote:
>
> On 6/30/25 4:45 PM, Jan Beulich wrote:
>> On 30.06.2025 16:38, Oleksii Kurochko wrote:
>>> On 6/30/25 4:33 PM, Oleksii Kurochko wrote:
>>>> On 6/26/25 4:59 PM, Jan Beulich wrote:
>>>>> On 10.06.2025 15:05, Oleksii Kurochko wrote:
>>>>>> --- a/xen/arch/riscv/include/asm/p2m.h
>>>>>> +++ b/xen/arch/riscv/include/asm/p2m.h
>>>>>> @@ -61,8 +61,28 @@ struct p2m_domain {
>>>>>> typedef enum {
>>>>>> p2m_invalid = 0, /* Nothing mapped here */
>>>>>> p2m_ram_rw, /* Normal read/write domain RAM */
>>>>>> + p2m_ram_ro, /* Read-only; writes are silently dropped */
>>>>> As indicated before - this type should be added when the special handling that
>>>>> it requires is also introduced.
>>>> Perhaps, I missed that. I will drop this type for now.
>>>>
>>>>>> + p2m_mmio_direct_dev,/* Read/write mapping of genuine Device MMIO area */
>>>>> What's the _dev suffix indicating here?
>>>> It indicates that it is device memory, probably, it isn't so necessary in case of RISC-V as
>>>> spec doesn't use such terminology. In RISC-V there is only available IO, NC. And we are
>>>> |using PTE_PBMT_IO for |p2m_mmio_direct_dev.
>>>>
>>>> Maybe it would be better just to rename s/p2m_mmio_direct_dev/p2m_mmio_direct_io.
>>> I forgot that p2m_mmio_direct_dev is used by common code for dom0less code (handle_passthrough_prop())
>> That'll want abstracting out, I think. I don't view it as helpful to clutter
>> RISC-V (and later perhaps also PPC) with Arm-specific terminology.
>
> Would it be better then just rename it to p2m_device? Then it won't clear for Arm which type of MMIO p2m's
> types is used as Arm has there MMIO types: *_dev, *_nc, *_c.
I don't understand why Arm matters here. P2M types want naming in a way that makes
sense for RISC-V.
> As an option (which I don't really like) it could be "#define p2m_mmio_direct_dev ARCH_specific_name" in
> asm/p2m.h to not touch common code.
A #define may be needed, but not one to _still_ introduce Arm naming into non-Arm
code.
Jan
On 6/30/25 5:50 PM, Jan Beulich wrote:
> On 30.06.2025 17:27, Oleksii Kurochko wrote:
>> On 6/30/25 4:45 PM, Jan Beulich wrote:
>>> On 30.06.2025 16:38, Oleksii Kurochko wrote:
>>>> On 6/30/25 4:33 PM, Oleksii Kurochko wrote:
>>>>> On 6/26/25 4:59 PM, Jan Beulich wrote:
>>>>>> On 10.06.2025 15:05, Oleksii Kurochko wrote:
>>>>>>> --- a/xen/arch/riscv/include/asm/p2m.h
>>>>>>> +++ b/xen/arch/riscv/include/asm/p2m.h
>>>>>>> @@ -61,8 +61,28 @@ struct p2m_domain {
>>>>>>> typedef enum {
>>>>>>> p2m_invalid = 0, /* Nothing mapped here */
>>>>>>> p2m_ram_rw, /* Normal read/write domain RAM */
>>>>>>> + p2m_ram_ro, /* Read-only; writes are silently dropped */
>>>>>> As indicated before - this type should be added when the special handling that
>>>>>> it requires is also introduced.
>>>>> Perhaps, I missed that. I will drop this type for now.
>>>>>
>>>>>>> + p2m_mmio_direct_dev,/* Read/write mapping of genuine Device MMIO area */
>>>>>> What's the _dev suffix indicating here?
>>>>> It indicates that it is device memory, probably, it isn't so necessary in case of RISC-V as
>>>>> spec doesn't use such terminology. In RISC-V there is only available IO, NC. And we are
>>>>> |using PTE_PBMT_IO for |p2m_mmio_direct_dev.
>>>>>
>>>>> Maybe it would be better just to rename s/p2m_mmio_direct_dev/p2m_mmio_direct_io.
>>>> I forgot that p2m_mmio_direct_dev is used by common code for dom0less code (handle_passthrough_prop())
>>> That'll want abstracting out, I think. I don't view it as helpful to clutter
>>> RISC-V (and later perhaps also PPC) with Arm-specific terminology.
>> Would it be better then just rename it to p2m_device? Then it won't clear for Arm which type of MMIO p2m's
>> types is used as Arm has there MMIO types: *_dev, *_nc, *_c.
> I don't understand why Arm matters here. P2M types want naming in a way that makes
> sense for RISC-V.
It doesn't matter.
But if we want to change the type name from p2m_mmio_direct_dev to p2m_mmio_direct or p2m_device then it will
affect Arm too as p2m_mmio_direct_dev is used in dom0less code which is also used by Arm.
I just re-used p2m_mmio_direct_dev as it looked for me pretty generic and clear for what this type is.
>> As an option (which I don't really like) it could be "#define p2m_mmio_direct_dev ARCH_specific_name" in
>> asm/p2m.h to not touch common code.
> A #define may be needed, but not one to _still_ introduce Arm naming into non-Arm
> code.
As I mentioned above that p2m_mmio_direct_dev sounds pretty generic to me and I am okay to use it for
RISC-V. But if you have better suggestions I will be happy to consider it.
~ Oleksii
On 02.07.2025 12:13, Oleksii Kurochko wrote:
>
> On 6/30/25 5:50 PM, Jan Beulich wrote:
>> On 30.06.2025 17:27, Oleksii Kurochko wrote:
>>> On 6/30/25 4:45 PM, Jan Beulich wrote:
>>>> On 30.06.2025 16:38, Oleksii Kurochko wrote:
>>>>> On 6/30/25 4:33 PM, Oleksii Kurochko wrote:
>>>>>> On 6/26/25 4:59 PM, Jan Beulich wrote:
>>>>>>> On 10.06.2025 15:05, Oleksii Kurochko wrote:
>>>>>>>> --- a/xen/arch/riscv/include/asm/p2m.h
>>>>>>>> +++ b/xen/arch/riscv/include/asm/p2m.h
>>>>>>>> @@ -61,8 +61,28 @@ struct p2m_domain {
>>>>>>>> typedef enum {
>>>>>>>> p2m_invalid = 0, /* Nothing mapped here */
>>>>>>>> p2m_ram_rw, /* Normal read/write domain RAM */
>>>>>>>> + p2m_ram_ro, /* Read-only; writes are silently dropped */
>>>>>>> As indicated before - this type should be added when the special handling that
>>>>>>> it requires is also introduced.
>>>>>> Perhaps, I missed that. I will drop this type for now.
>>>>>>
>>>>>>>> + p2m_mmio_direct_dev,/* Read/write mapping of genuine Device MMIO area */
>>>>>>> What's the _dev suffix indicating here?
>>>>>> It indicates that it is device memory, probably, it isn't so necessary in case of RISC-V as
>>>>>> spec doesn't use such terminology. In RISC-V there is only available IO, NC. And we are
>>>>>> |using PTE_PBMT_IO for |p2m_mmio_direct_dev.
>>>>>>
>>>>>> Maybe it would be better just to rename s/p2m_mmio_direct_dev/p2m_mmio_direct_io.
>>>>> I forgot that p2m_mmio_direct_dev is used by common code for dom0less code (handle_passthrough_prop())
>>>> That'll want abstracting out, I think. I don't view it as helpful to clutter
>>>> RISC-V (and later perhaps also PPC) with Arm-specific terminology.
>>> Would it be better then just rename it to p2m_device? Then it won't clear for Arm which type of MMIO p2m's
>>> types is used as Arm has there MMIO types: *_dev, *_nc, *_c.
>> I don't understand why Arm matters here. P2M types want naming in a way that makes
>> sense for RISC-V.
>
> It doesn't matter.
> But if we want to change the type name from p2m_mmio_direct_dev to p2m_mmio_direct or p2m_device then it will
> affect Arm too as p2m_mmio_direct_dev is used in dom0less code which is also used by Arm.
As said - imo this needs abstracting away.
> I just re-used p2m_mmio_direct_dev as it looked for me pretty generic and clear for what this type is.
>
>>> As an option (which I don't really like) it could be "#define p2m_mmio_direct_dev ARCH_specific_name" in
>>> asm/p2m.h to not touch common code.
>> A #define may be needed, but not one to _still_ introduce Arm naming into non-Arm
>> code.
>
> As I mentioned above that p2m_mmio_direct_dev sounds pretty generic to me and I am okay to use it for
> RISC-V. But if you have better suggestions I will be happy to consider it.
Well, the name we use on x86 (and I think this was quite obviously implied
by earlier replies of mine): p2m_mmio_direct.
Jan
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