On 6/5/2026 9:28 AM, Daniel Henrique Barboza wrote:
On 6/5/2026 3:59 AM, Icenowy Zheng wrote:
在 2026-06-04四的 06:52 -0300，Daniel Henrique Barboza写道：
From: Fei Wu <[email protected]>
The harts requirements of RISC-V server platform [1] require RVA23
ISA
profile support and others.
This patch provides a new "riscv-server-ref" CPU to go along with the
future "riscv-server-ref" board.
[1]
https://github.com/riscv-non-isa/riscv-server-platform/blob/main/server_platform_requirements.adoc
Signed-off-by: Fei Wu <[email protected]>
Signed-off-by: Daniel Henrique Barboza
<[email protected]>
---
target/riscv/cpu-qom.h | 1 +
target/riscv/cpu.c | 11 +++++++++++
2 files changed, 12 insertions(+)
diff --git a/target/riscv/cpu-qom.h b/target/riscv/cpu-qom.h
index 30dcdcfaae..a150acd151 100644
--- a/target/riscv/cpu-qom.h
+++ b/target/riscv/cpu-qom.h
@@ -42,6 +42,7 @@
#define TYPE_RISCV_CPU_RVA22S64
RISCV_CPU_TYPE_NAME("rva22s64")
#define TYPE_RISCV_CPU_RVA23U64
RISCV_CPU_TYPE_NAME("rva23u64")
#define TYPE_RISCV_CPU_RVA23S64
RISCV_CPU_TYPE_NAME("rva23s64")
+#define TYPE_RISCV_CPU_RVSERVER_REF RISCV_CPU_TYPE_NAME("riscv-
server-ref")
#define TYPE_RISCV_CPU_IBEX
RISCV_CPU_TYPE_NAME("lowrisc-ibex")
#define TYPE_RISCV_CPU_SHAKTI_C RISCV_CPU_TYPE_NAME("shakti-
c")
#define TYPE_RISCV_CPU_SIFIVE_E RISCV_CPU_TYPE_NAME("sifive-
e")
diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 3f0f931335..c4a5a7f1cb 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -3315,6 +3315,17 @@ static const TypeInfo riscv_cpu_type_infos[] =
{
#endif
),
+ DEFINE_RISCV_CPU(TYPE_RISCV_CPU_RVSERVER_REF,
TYPE_RISCV_BARE_CPU,
+ .misa_mxl_max = MXL_RV64,
+ .profile = &RVA23S64,
+
+ .cfg.ext_zkr = true,
+ .cfg.ext_svadu = true,
+ .cfg.ext_sdext = true,
+
+ .cfg.max_satp_mode = VM_1_10_SV48,
Here it only declares the maximum supported SATP mode is Sv48, but the
RVSP spec requires Sv48, and the RVSP REF machine created in the next
patch also requires it (because the above 4G PCIe memory space is
beyond 40-bit physical address space).
Without `,sv48=on` explicitly enabled on the CPU, booting EDK2 firmware
will fail because of the out-of-address-space PCIe memory space.
You're correct. We're not initializing satp_mode to max_satp_mode, so the
default value is being set to sv39. This seems to be the case for all
CPUs, not just this one. For some reason I thought we were defaulting
to the max_satp_mode. I need to understand why sv39 is being set as
default (i.e. why not BARE?).
Got an update. It turns out that what we're seeing is something that is
only happening to this CPU we're trying to add.
The way satp mode is set on QEMU assuming no command line input:
- "Bare" CPUs, aka CPUs that has just I or E enabled: default to BARE;
- Profile CPUs: default to the minimum required by the spec. E.g. for
RVA23 the default is set to sv39;
- all other CPUs: default to satp_mode_max from the CPU definition.
The riscv-server-ref CPU is a BARE CPU that is using the profile framework
to enable extensions. So for all intents and purposes the code is treating
it as a profile CPU with extra stuff. Which is good, but then the
satp setting from RVA23 (sv39) is overwriting satp_mode_max from the
CPU definition.
I believe the way we're creating riscv-server-ref here is correct, so what
I'm going to do is send a couple of fixes to allow riscv-server-ref to use
RVA23 as a base and honor its satp_mode_max value too.
Thanks,
Daniel
As far as -cpu riscv-server-ref goes we do not want to force users to
specify sv48=on. The CPU should default to that without any additional
command line.
Thanks for reporting this. There might be extra stuff to do in the code
base before adding this CPU (maybe adding a 'satp_mode' attribute and
make CPUs default to that value, like profile CPUs do).
Maybe a RVSERVER profile could be defined for CPUs conformant to server
platform spec (because that spec really adds some requireed
extensions), and use it for RVSERVER_REF CPU type?
Treating riscv-server-ref as a profile style CPU might be an easier alternative
to have what we want but I wonder if allowing CPUs to set a default satp_mode
is better long term. I'll see what I can do.
Thanks,
Daniel
Thanks,
Icenowy
+ ),
+
#if defined(CONFIG_TCG) && !defined(CONFIG_USER_ONLY)
DEFINE_RISCV_CPU(TYPE_RISCV_CPU_BASE128, TYPE_RISCV_DYNAMIC_CPU,
.cfg.max_satp_mode = VM_1_10_SV57,
