On 12/8/25 4:05 PM, Jan Beulich wrote:
On 01.12.2025 11:24, Oleksii Kurochko wrote:
--- a/xen/arch/riscv/include/asm/sbi.h
+++ b/xen/arch/riscv/include/asm/sbi.h
@@ -14,8 +14,15 @@
#include <xen/cpumask.h>
-#define SBI_EXT_0_1_CONSOLE_PUTCHAR 0x1
-#define SBI_EXT_0_1_SHUTDOWN 0x8
+#define SBI_EXT_0_1_SET_TIMER 0x0
+#define SBI_EXT_0_1_CONSOLE_PUTCHAR 0x1
Why the padding adjustment when ...
+#define SBI_EXT_0_1_CONSOLE_GETCHAR 0x2
+#define SBI_EXT_0_1_CLEAR_IPI 0x3
+#define SBI_EXT_0_1_SEND_IPI 0x4
+#define SBI_EXT_0_1_REMOTE_FENCE_I 0x5
+#define SBI_EXT_0_1_REMOTE_SFENCE_VMA 0x6
+#define SBI_EXT_0_1_REMOTE_SFENCE_VMA_ASID 0x7
... you immediately have one that doesn't fit?
IDK, the padding adjustment shouldn't be done in this way.
I will correct it.
--- /dev/null
+++ b/xen/arch/riscv/vsbi/vsbi-legacy-extension.c
@@ -0,0 +1,37 @@
+
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <xen/lib.h>
+#include <xen/sched.h>
+
+#include <asm/processor.h>
+#include <asm/vsbi.h>
+
+static int vsbi_legacy_ecall_handler(struct vcpu *vcpu, unsigned long eid,
+ unsigned long fid,
+ struct cpu_user_regs *regs)
+{
+ int ret = 0;
+
+ switch ( eid )
+ {
+ case SBI_EXT_0_1_CONSOLE_PUTCHAR:
+ printk("%c", (char)regs->a0);
This is guest output, so shouldn't use plain printk().
I think that I don't know what should be used instead. Could you suggest me
something
or point to the code in other arch-s?
Or do you mean that guest_printk() should be used?
+ break;
+
+ case SBI_EXT_0_1_CONSOLE_GETCHAR:
+ regs->a0 = SBI_ERR_NOT_SUPPORTED;
This will be overwritten with the return value you pass to the caller (i.e. 0),
by that caller (i.e. vsbi_handle_ecall()).
Oh, thanks. It should be "ret = SBI_ERR_NOT_SUPPORTED;" here.
+ break;
+
+ default:
+ panic("%s: Unsupported ecall: FID: #%lx, EID: #%lx\n",
+ __func__, fid, eid);
Please don't. domain_crash() may be okay to use here, but crashing the
hypervisor
because of unexpected guest input isn't okay.
|domain_crash()| is better. I also considered just
returning|SBI_ERR_NOT_SUPPORTED|,
but it wasn’t too convenient for debugging which FID/EID the guest was called,
so I started using|panic()| instead.
Thanks.
~ Oleksii
