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Fast-track extension proposal for H/W PTE A/D updating
Greetings !
We are submitting for your consideration an extension for HW PTE A/D updating (Svadu) controls.
As you might recall the privileged specification defines two HW behaviors for PTE A/D bits
Greetings !
We are submitting for your consideration an extension for HW PTE A/D updating (Svadu) controls.
As you might recall the privileged specification defines two HW behaviors for PTE A/D bits
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By
Ved Shanbhogue
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#1138
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Re: Is a Full VA or Block-Aligned VA Saved into *MTVAL on a page-fault?
+tech-privileged@...
cc'ing mailing list, too....
+tech-privileged@...
cc'ing mailing list, too....
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By
David Kruckemyer
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#1137
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Is a Full VA or Block-Aligned VA Saved into *MTVAL on a page-fault?
When a breakpoint, access-fault, or page-fault exception occur on a CMO instruction (cbo.clean, cbo.flush, cbo.inval, cbo.zero), is the full virtual address provided in the register identified by rs1
When a breakpoint, access-fault, or page-fault exception occur on a CMO instruction (cbo.clean, cbo.flush, cbo.inval, cbo.zero), is the full virtual address provided in the register identified by rs1
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By
Ricardo Ramirez
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#1136
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Re: Fast-track extension proposal V3 for "Sv32 Svpbmt"
Okay
Okay
Okay, here is the rewritten sentence:
The Svpbmt32 extension allows the two highest bits of a PTE
(BIT[31:30]) to be used as PBMT (Page-Based Memory Type) instead of
PA[33:32] for Sv32.
Okay
Okay
Okay, here is the rewritten sentence:
The Svpbmt32 extension allows the two highest bits of a PTE
(BIT[31:30]) to be used as PBMT (Page-Based Memory Type) instead of
PA[33:32] for Sv32.
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By
Guo Ren
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#1135
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Re: Fast-track extension proposal for Resumable Non-Maskable Interrupts (Smrnmi)
If these registers are allowed to be reused for other purposes (e.g. another privilege mode), then those other purposes would either require masking NMIs or would make NMIs received in that mode
If these registers are allowed to be reused for other purposes (e.g. another privilege mode), then those other purposes would either require masking NMIs or would make NMIs received in that mode
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By
andrew@...
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#1134
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Re: Fast-track extension proposal for Resumable Non-Maskable Interrupts (Smrnmi)
Hi Andrew,
Just one thought, this change introduces a bank of context saving registers that could also be re-used/applied for additional purposes such as a lightweight TEE-OS (where we are looking
Hi Andrew,
Just one thought, this change introduces a bank of context saving registers that could also be re-used/applied for additional purposes such as a lightweight TEE-OS (where we are looking
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By
Mark Hill
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#1133
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Fast-track extension proposal for Resumable Non-Maskable Interrupts (Smrnmi)
Hi,
We're submitting for your consideration an extension for resumable non-maskable interrupt (RNMI) support.
You might recall that the current non-maskable interrupt support defined in the M-mode
Hi,
We're submitting for your consideration an extension for resumable non-maskable interrupt (RNMI) support.
You might recall that the current non-maskable interrupt support defined in the M-mode
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By
andrew@...
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#1132
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Re: PMP shared permissions for S and U
Not all OSes require or desire VM address mapping, especially in the embedded space (or so I've been led to believe) - yet they still need some level of privilege protection layering.
That's where
Not all OSes require or desire VM address mapping, especially in the embedded space (or so I've been led to believe) - yet they still need some level of privilege protection layering.
That's where
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By
Allen Baum
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#1131
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Re: PMP shared permissions for S and U
Out of curiosity, what's the point of supporting S-mode if not to use paged virtual memory? My understanding of things was that S-mode provides virtual memory, a secondary level of interrupt/exception
Out of curiosity, what's the point of supporting S-mode if not to use paged virtual memory? My understanding of things was that S-mode provides virtual memory, a secondary level of interrupt/exception
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By
Anthony Coulter
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#1130
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Re: PMP shared permissions for S and U
Note: I'm not sure if the TG's email list is up yet. If not, check with the Security HC.
Note: I'm not sure if the TG's email list is up yet. If not, check with the Security HC.
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By
Greg Favor
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#1129
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Re: PMP shared permissions for S and U
Jeff;
FYI. SPMP TG is awaiting final approval from Technical Steering Commitee.
Regards,
Manuel Offenberg
Seagate Research
Jeff;
FYI. SPMP TG is awaiting final approval from Technical Steering Commitee.
Regards,
Manuel Offenberg
Seagate Research
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By
Manuel Offenberg <manuel.a.offenberg@...>
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#1128
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Re: PMP shared permissions for S and U
Hi Greg,
In our world we don’t have MMU, just PMP. The inability to supply separate permissions to S and U limits the usefulness of PMP in our environment.
I subscribed to SPMP now. I’ll
Hi Greg,
In our world we don’t have MMU, just PMP. The inability to supply separate permissions to S and U limits the usefulness of PMP in our environment.
I subscribed to SPMP now. I’ll
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By
Jeff Scott
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#1127
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Re: PMP shared permissions for S and U
PMP was architected to be a mechanism to protect M-mode software and resources from non-M-mode software and devices. This complements the MMU which serves to protect and isolate between S-mode and
PMP was architected to be a mechanism to protect M-mode software and resources from non-M-mode software and devices. This complements the MMU which serves to protect and isolate between S-mode and
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By
Greg Favor
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#1126
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PMP shared permissions for S and U
Hello,
I am curious why the PMP treats S and U mode accesses identically? Is anyone aware of a standard extension that allows for different permissions for S and U?
Thanks,
Jeff
Hello,
I am curious why the PMP treats S and U mode accesses identically? Is anyone aware of a standard extension that allows for different permissions for S and U?
Thanks,
Jeff
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By
Jeff Scott
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#1125
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Re: Fast-track extension proposal V3 for "Sv32 Svpbmt"
It seems like you have dropped a bunch of text from the prior versions - which is probably part of what leads to some of my questions below.
Maybe better to say "The Svpbmt32 extension allows the
It seems like you have dropped a bunch of text from the prior versions - which is probably part of what leads to some of my questions below.
Maybe better to say "The Svpbmt32 extension allows the
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By
Greg Favor
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#1124
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Fast-track extension proposal V3 for "Sv32 Svpbmt"
Hi all,
Here is the third version of the proposal.
V2: https://lists.riscv.org/g/tech-privileged/message/1079
V1: https://lists.riscv.org/g/tech-privileged/message/1051
This posting to this
Hi all,
Here is the third version of the proposal.
V2: https://lists.riscv.org/g/tech-privileged/message/1079
V1: https://lists.riscv.org/g/tech-privileged/message/1051
This posting to this
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By
Guo Ren
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#1123
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Re: Are pages allowed to cross PMA regions?
Thank you all for the valuable input!
In summary, it is possible to have virtual memory pages that straddle multiple PMA and PMP regions. There are simplifications or implementation decisions that can
Thank you all for the valuable input!
In summary, it is possible to have virtual memory pages that straddle multiple PMA and PMP regions. There are simplifications or implementation decisions that can
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By
Andres Amaya Garcia
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#1122
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Re: Are pages allowed to cross PMA regions?
>For TLBs, the important simplification is PMP/PMA aren't <4KiB in
>granularity, as then existing TLB entires can be used to cache
>permissions.
Yes - this makes a lot of sense. What about the case
>For TLBs, the important simplification is PMP/PMA aren't <4KiB in
>granularity, as then existing TLB entires can be used to cache
>permissions.
Yes - this makes a lot of sense. What about the case
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By
Tariq Kurd
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#1121
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Re: Are pages allowed to cross PMA regions?
>For TLBs, the important simplification is PMP/PMA aren't <4KiB in
>granularity, as then existing TLB entires can be used to cache
>permissions.
Yes - this makes a lot of sense. What about the case
>For TLBs, the important simplification is PMP/PMA aren't <4KiB in
>granularity, as then existing TLB entires can be used to cache
>permissions.
Yes - this makes a lot of sense. What about the case
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By
Tariq Kurd
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#1120
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Re: Are pages allowed to cross PMA regions?
|| In particular, a portion of a misaligned store that passes the PMP check may become visible, even if another portion fails the PMP check
| I had no idea this was in the spec - so I'm glad you added
|| In particular, a portion of a misaligned store that passes the PMP check may become visible, even if another portion fails the PMP check
| I had no idea this was in the spec - so I'm glad you added
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By
Krste Asanovic
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#1119
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