RISC-V RVA23 profile support

[yangfei at iscas.ac.cn]

Hi,

Seems better to discuss here on this RISC-V specific list: https://mail.openjdk.org/pipermail/riscv-port-dev
AFAIK, these options (RVA20, RVA22 and RVA23) are rarely used. The Hotspot JVM relies on RISC-V hardware probing interface [1] to detect the availability of various extensions on startup.
This means if you have an extension like RVV, the JVM can auto-detect and JVM JIT compiler or runtime will make use of that to emit more efficient code. Hope that helps!

Regards,
Fei

[1] https://docs.kernel.org/arch/riscv/hwprobe.html


-----Original Messages-----
From:"Pushkar Kulkarni" <pushkar.kulkarni at canonical.com>
Sent Time:2025-09-01 14:34:23 (Monday)
To: jdk-dev at openjdk.org
Cc: 
Subject: RISC-V RVA23 profile support

Hi there,  
  This is a RISC-V question and I hope I am writing to the right list.  
  
  In terms of support for RISC-V profiles, I gather from [1] that RVA20 is currently the default profile; the newest RVA23 is experimental.  From some digging, I also gathered that Hotspot now supports close to half of the mandatory extensions of RVA23. Do we have a roadmap, or a plan, for making RVA23 the default? I ask this in the context of the upcoming Ubuntu 25.10 release raising the RISC-V baseline to RVA23.  
  
  Regards,  
  Pushkar  
  
  [1] https://github.com/openjdk/jdk/blob/28942406020881be79b7543105b9eb2a0dda429e/src/hotspot/cpu/riscv/globals_riscv.hpp#L97   
  [2] https://www.phoronix.com/news/Ubuntu-25.10-To-Require-RVA23


</pushkar.kulkarni at canonical.com>