Re: [PATCH] kexec: don't use kexec_file_load on XEN

2024-01-25 Thread Simon Horman
On Tue, Jan 16, 2024 at 06:14:31PM +0100, Jiri Bohac wrote:
> Since commit 29fe5067ed07 ("kexec: make -a the default")
> kexec tries the kexec_file_load syscall first and only falls back to 
> kexec_load on
> selected error codes.
> 
> This effectively breaks kexec on XEN, unless -c is pecified to force the 
> kexec_load
> syscall.
> 
> The XEN-specific functions (xen_kexec_load / xen_kexec_unload) are only called
> from my_load / k_unload, i.e. the kexec_load code path.
> 
> With -p (panic kernel) kexec_file_load on XEN fails with -EADDRNOTAVAIL (crash
> kernel reservation is ignored by the kernel on XEN), which is not in the list
> of return codes that cause the fallback to kexec_file.
> 
> Without -p kexec_file_load actualy leads to a kernel oops on v6.4.0
> (needs to be dubugged separately).
> 
> Signed-off-by: Jiri Bohac 
> Fixes: 29fe5067ed07 ("kexec: make -a the default")

Thanks Jiri,

and sorry for the delay.
Applied to main.

___
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec


[PATCH] kexec: don't use kexec_file_load on XEN

2024-01-16 Thread Jiri Bohac
Since commit 29fe5067ed07 ("kexec: make -a the default")
kexec tries the kexec_file_load syscall first and only falls back to kexec_load 
on
selected error codes.

This effectively breaks kexec on XEN, unless -c is pecified to force the 
kexec_load
syscall.

The XEN-specific functions (xen_kexec_load / xen_kexec_unload) are only called
from my_load / k_unload, i.e. the kexec_load code path.

With -p (panic kernel) kexec_file_load on XEN fails with -EADDRNOTAVAIL (crash
kernel reservation is ignored by the kernel on XEN), which is not in the list
of return codes that cause the fallback to kexec_file.

Without -p kexec_file_load actualy leads to a kernel oops on v6.4.0
(needs to be dubugged separately).

Signed-off-by: Jiri Bohac 
Fixes: 29fe5067ed07 ("kexec: make -a the default")
---
 kexec/kexec.8 | 1 +
 kexec/kexec.c | 4 
 2 files changed, 5 insertions(+)

diff --git a/kexec/kexec.8 b/kexec/kexec.8
index b969cea..9e995fe 100644
--- a/kexec/kexec.8
+++ b/kexec/kexec.8
@@ -162,6 +162,7 @@ Specify that the new kernel is of this
 .TP
 .BI \-s\ (\-\-kexec-file-syscall)
 Specify that the new KEXEC_FILE_LOAD syscall should be used exclusively.
+Ignored on XEN.
 .TP
 .BI \-c\ (\-\-kexec-syscall)
 Specify that the old KEXEC_LOAD syscall should be used exclusively.
diff --git a/kexec/kexec.c b/kexec/kexec.c
index 08edfca..9d0ec46 100644
--- a/kexec/kexec.c
+++ b/kexec/kexec.c
@@ -1685,6 +1685,10 @@ int main(int argc, char *argv[])
}
}
}
+   if (xen_present()) {
+   do_kexec_file_syscall = 0;
+   do_kexec_fallback = 0;
+   }
if (do_kexec_file_syscall) {
if (do_load_jump_back_helper && !do_kexec_fallback)
die("--load-jump-back-helper not supported with 
kexec_file_load\n");
-- 
Jiri Bohac 
SUSE Labs, Prague, Czechia


___
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec