From 86b1b8ec3d9d0508a95540e368432291b883837f Mon Sep 17 00:00:00 2001
From: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Date: Wed, 5 Mar 2025 15:44:12 +0100
Subject: [PATCH] xen/riscv: drop CONFIG_RISCV_ISA_RV64G

'G' stands for "imafd_zicsr_zifencei".

Extensions 'f' and 'd' aren't really needed for Xen, and allowing floating
point registers to be used can lead to crashes.

Extensions 'i', 'm', 'a', 'zicsr', and 'zifencei' are necessary for the
operation of Xen, which is why they are used explicitly (unconditionally)
in -march.

Drop "Base ISA" choice from riscv/Kconfig as it is always empty.

Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
---
 xen/arch/riscv/Kconfig | 18 ------------------
 xen/arch/riscv/arch.mk |  8 +++++---
 2 files changed, 5 insertions(+), 21 deletions(-)

diff --git a/xen/arch/riscv/Kconfig b/xen/arch/riscv/Kconfig
index fa95cd0a42..d882e0a059 100644
--- a/xen/arch/riscv/Kconfig
+++ b/xen/arch/riscv/Kconfig
@@ -23,24 +23,6 @@ endmenu
 
 menu "ISA Selection"
 
-choice
-	prompt "Base ISA"
-	default RISCV_ISA_RV64G if RISCV_64
-	help
-	  This selects the base ISA extensions that Xen will target.
-
-config RISCV_ISA_RV64G
-	bool "RV64G"
-	help
-	  Use the RV64I base ISA, plus
-	  "M" for multiply/divide,
-	  "A" for atomic instructions,
-	  “F”/"D" for  {single/double}-precision floating-point instructions,
-	  "Zicsr" for control and status register access,
-	  "Zifencei" for instruction-fetch fence.
-
-endchoice
-
 config RISCV_ISA_C
 	bool "Compressed extension"
 	default y
diff --git a/xen/arch/riscv/arch.mk b/xen/arch/riscv/arch.mk
index 17827c302c..3034da76cb 100644
--- a/xen/arch/riscv/arch.mk
+++ b/xen/arch/riscv/arch.mk
@@ -6,10 +6,12 @@ $(call cc-options-add,CFLAGS,CC,$(EMBEDDED_EXTRA_CFLAGS))
 riscv-abi-$(CONFIG_RISCV_32) := -mabi=ilp32
 riscv-abi-$(CONFIG_RISCV_64) := -mabi=lp64
 
-riscv-march-$(CONFIG_RISCV_ISA_RV64G) := rv64g
-riscv-march-$(CONFIG_RISCV_ISA_C)       := $(riscv-march-y)c
+riscv-march-$(CONFIG_RISCV_64) := rv64
+riscv-march-y += ima
+riscv-march-$(CONFIG_RISCV_ISA_C) += c
+riscv-march-y += _zicsr_zifencei
 
-riscv-generic-flags := $(riscv-abi-y) -march=$(riscv-march-y)
+riscv-generic-flags := $(riscv-abi-y) -march=$(subst $(space),,$(riscv-march-y))
 
 # check-extension: Check whether extenstion is supported by a compiler and
 #                  an assembler.