Hi Jürgen,
On 13.11.25 17:43, Jürgen Groß wrote:
On 13.11.25 16:32, Grygorii Strashko wrote:
Hi Jürgen,
On 13.11.25 16:46, Juergen Gross wrote:
On 13.11.25 15:39, Jürgen Groß wrote:
On 13.11.25 14:23, Jan Beulich wrote:
On 13.11.2025 14:18, Grygorii Strashko wrote:
On 13.11.25 14:30, Jan Beulich wrote:
On 11.11.2025 18:54, Grygorii Strashko wrote:
--- a/xen/arch/x86/hvm/hypercall.c
+++ b/xen/arch/x86/hvm/hypercall.c
@@ -29,10 +29,12 @@ long hvm_memory_op(unsigned long cmd,
XEN_GUEST_HANDLE_PARAM(void) arg)
return -ENOSYS;
}
- if ( !vcpu_is_hcall_compat(current) )
- rc = do_memory_op(cmd, arg);
- else
+#ifdef CONFIG_COMPAT
+ if ( vcpu_is_hcall_compat(current) )
rc = compat_memory_op(cmd, arg);
+ else
+#endif
+ rc = do_memory_op(cmd, arg);
Why would this be needed when vcpu_is_hcall_compat() already honors
CONFIG_COMPAT?
(Same question then applies elsewhere, of course.)
This I do not like by myself, but I was not able to find other options :(
hypercall-defs.h is autogenerated and it's the only one place where functions
declarations like do_x_op() are appeared or disappeared.
So build is failing without ifdefs as compiler can't find compat_memory_op()
declaration.
Oh, I see; I hadn't thought of that aspect. I wonder if we wouldn't better take
care of that in the machinery there. Cc-ing Jürgen, who did introduce this
originally. Maybe he has concrete arguments against us doing so.
No arguments against it.
You probably will need a new Prefix defined (e.g. compat_always) and set it via
#define PREFIX_compat_always compat
unconditionally. Then it should be possible to have
Prefix: compat_always
memory_op(...)
outside of #ifdefs and drop the memory_op() in the #ifdef CONFIG_COMPAT section.
Oh, this might be wrong, as this will break the PV32 memory_op() hypercall.
You need to keep the current memory_op() in the #ifdef CONFIG_COMPAT section
and move the compat_always stuff into an #else part of the CONFIG_COMPAT.
This should result in the compat_memory_op() prototype to be always available.
Having no related function should be no problem due to DCO in case CONFIG_COMPAT
isn't defined.
Smth like this, right?
diff --git a/xen/include/hypercall-defs.c b/xen/include/hypercall-defs.c
index 338d7afe3048..e85943320bd2 100644
--- a/xen/include/hypercall-defs.c
+++ b/xen/include/hypercall-defs.c
@@ -80,6 +80,8 @@ rettype: compat int
#define PREFIX_compat
#endif
+#define PREFIX_compat_always compat
+
#ifdef CONFIG_ARM
#define PREFIX_dep dep
#define PREFIX_do_arm do_arm
@@ -156,6 +158,9 @@ platform_op(compat_platform_op_t *u_xenpf_op)
#ifdef CONFIG_KEXEC
kexec_op(unsigned int op, void *uarg)
#endif
+#else
+prefix: PREFIX_compat_always
This should be:
+prefix: compat_always
Unfortunately, ^ is not working it generates
long compat_always_memory_op(unsigned int cmd, XEN_GUEST_HANDLE_PARAM(void)
arg);
My version works "prefix: PREFIX_compat_always"
--
Best regards,
-grygorii
