* [bug#75027] [PATCH 0/3] 'guix system reconfigure' loads system for kexec reboot
@ 2024-12-22 15:56 Ludovic Courtès
2024-12-22 15:57 ` [bug#75027] [PATCH 1/3] syscalls: Add ‘kexec-load-file’ Ludovic Courtès
` (3 more replies)
0 siblings, 4 replies; 5+ messages in thread
From: Ludovic Courtès @ 2024-12-22 15:56 UTC (permalink / raw)
To: 75027
Cc: Jakob Kirsch, Ludovic Courtès, Christopher Baines,
Josselin Poiret, Ludovic Courtès, Mathieu Othacehe,
Simon Tournier, Tobias Geerinckx-Rice
Hello Guix,
Following work by Jakob Kirsch adding kexec support in the Shepherd
(the new ‘reboot -k’ option), here’s the Guix side of it: with these
patches, ‘guix system reconfigure’ loads the new system so that one
can run ‘reboot -k’ to quickly reboot into it.
Thoughts?
Ludo’.
PS: It took me a while to debug until I realized it was working
very well: it’s just that I was booting a kernel with “quiet”
on its command line, so I couldn’t see anything. 🤦
Ludovic Courtès (3):
syscalls: Add ‘kexec-load-file’.
system: Export ‘…-initrd-file’ and ‘…-root-file-system’.
reconfigure: Call ‘kexec-load-file’.
gnu/system.scm | 4 +-
gnu/tests/reconfigure.scm | 77 +++++++++++++++++++++++++++++
guix/build/syscalls.scm | 54 ++++++++++++++++++++
guix/scripts/system/reconfigure.scm | 25 ++++++++++
tests/syscalls.scm | 13 +++++
5 files changed, 172 insertions(+), 1 deletion(-)
base-commit: 9f53e10235cced7a85697481c859829742b9912c
--
2.46.0
^ permalink raw reply [flat|nested] 5+ messages in thread
* [bug#75027] [PATCH 1/3] syscalls: Add ‘kexec-load-file’.
2024-12-22 15:56 [bug#75027] [PATCH 0/3] 'guix system reconfigure' loads system for kexec reboot Ludovic Courtès
@ 2024-12-22 15:57 ` Ludovic Courtès
2024-12-22 15:57 ` [bug#75027] [PATCH 2/3] system: Export ‘…-initrd-file’ and ‘…-root-file-system’ Ludovic Courtès
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Ludovic Courtès @ 2024-12-22 15:57 UTC (permalink / raw)
To: 75027; +Cc: Ludovic Courtès
* guix/build/syscalls.scm (string->utf-8/nul-terminated)
(kexec-load-file): New procedures.
* tests/syscalls.scm ("kexec-load-file"): New test.
Change-Id: I3724226a14ecc07f346e77519fb5b0591096c7f6
---
guix/build/syscalls.scm | 54 +++++++++++++++++++++++++++++++++++++++++
tests/syscalls.scm | 13 ++++++++++
2 files changed, 67 insertions(+)
diff --git a/guix/build/syscalls.scm b/guix/build/syscalls.scm
index 2c20edf058..f8c9937f54 100644
--- a/guix/build/syscalls.scm
+++ b/guix/build/syscalls.scm
@@ -146,6 +146,12 @@ (define-module (guix build syscalls)
clone
setns
+ kexec-load-file
+ KEXEC_FILE_UNLOAD
+ KEXEC_FILE_ON_CRASH
+ KEXEC_FILE_NO_INITRAMFS
+ KEXEC_FILE_DEBUG
+
PF_PACKET
AF_PACKET
all-network-interface-names
@@ -765,6 +771,54 @@ (define-as-needed load-linux-module
(list (strerror err))
(list err)))))))
+(define (string->utf-8/nul-terminated str)
+ "Serialize STR to UTF-8; return the resulting bytevector, including
+terminating nul character."
+ (let* ((source (string->utf8 str))
+ (bv (make-bytevector (+ (bytevector-length source) 1) 0)))
+ (bytevector-copy! source 0 bv 0 (bytevector-length source))
+ bv))
+
+;; Constants from <linux/kexec.h>.
+(define KEXEC_FILE_UNLOAD #x00000001)
+(define KEXEC_FILE_ON_CRASH #x00000002)
+(define KEXEC_FILE_NO_INITRAMFS #x00000004)
+(define KEXEC_FILE_DEBUG #x00000008)
+
+(define kexec-load-file
+ (let* ((proc (syscall->procedure int "syscall"
+ (list long ;sysno
+ int ;kernel fd
+ int ;initrd fd
+ unsigned-long ;cmdline length
+ '* ;cmdline
+ unsigned-long))) ;flags
+ ;; TODO: Don't do this.
+ (syscall-id (match (utsname:machine (uname))
+ ("i686" 320)
+ ("x86_64" 320)
+ ("armv7l" 401)
+ ("aarch64" 401)
+ ;; XXX: There's apparently no support for ppc64le and
+ ;; riscv64.
+ (_ #f))))
+ (lambda* (kernel-fd initrd-fd command-line #:optional (flags 0))
+ "Load for eventual use of kexec(8) the Linux kernel from
+@var{kernel-fd}, its initial RAM disk from @var{initrd-fd}, with the given
+@var{command-line} (a string). Optionally, @var{flags} can be a bitwise or of
+the KEXEC_FILE_* constants."
+ (let*-values (((command-line)
+ (string->utf-8/nul-terminated command-line))
+ ((ret err)
+ (proc syscall-id kernel-fd initrd-fd
+ (bytevector-length command-line)
+ (bytevector->pointer command-line)
+ flags)))
+ (when (= ret -1)
+ (throw 'system-error "kexec-load-file" "~A"
+ (list (strerror err))
+ (list err)))))))
+
(define (linux-process-flags pid) ;copied from the Shepherd
"Return the process flags of @var{pid} (or'd @code{PF_} constants), assuming
the Linux /proc file system is mounted; raise a @code{system-error} exception
diff --git a/tests/syscalls.scm b/tests/syscalls.scm
index 13f4f11721..eef864d097 100644
--- a/tests/syscalls.scm
+++ b/tests/syscalls.scm
@@ -679,6 +679,19 @@ (define perform-container-tests?
(lambda args
(system-error-errno args))))))
+(when (or (zero? (getuid))
+ (not (string-contains %host-type "linux")))
+ (test-skip 1))
+(test-equal "kexec-load-file"
+ EPERM
+ (catch 'system-error
+ (lambda ()
+ (let ((fd1 (open-fdes "/dev/null" O_RDONLY))
+ (fd2 (open-fdes "/dev/null" O_RDONLY)))
+ (kexec-load-file fd1 fd2 "gnu.repl=yes")))
+ (lambda args
+ (system-error-errno args))))
+
(test-end)
(false-if-exception (delete-file temp-file))
--
2.46.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [bug#75027] [PATCH 2/3] system: Export ‘…-initrd-file’ and ‘…-root-file-system’.
2024-12-22 15:56 [bug#75027] [PATCH 0/3] 'guix system reconfigure' loads system for kexec reboot Ludovic Courtès
2024-12-22 15:57 ` [bug#75027] [PATCH 1/3] syscalls: Add ‘kexec-load-file’ Ludovic Courtès
@ 2024-12-22 15:57 ` Ludovic Courtès
2024-12-22 15:57 ` [bug#75027] [PATCH 3/3] reconfigure: Call ‘kexec-load-file’ Ludovic Courtès
2024-12-22 21:47 ` [bug#75027] [PATCH 0/3] 'guix system reconfigure' loads system for kexec reboot Jakob Kirsch via Guix-patches via
3 siblings, 0 replies; 5+ messages in thread
From: Ludovic Courtès @ 2024-12-22 15:57 UTC (permalink / raw)
To: 75027; +Cc: Ludovic Courtès
* gnu/system.scm (operating-system-initrd-file): Fix docstring and
export.
(operating-system-root-file-system): Export.
Change-Id: I5254d82ce547e8014027ed20675b8bfe5a5847c5
---
gnu/system.scm | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/gnu/system.scm b/gnu/system.scm
index dfcb8fb279..252a26cac3 100644
--- a/gnu/system.scm
+++ b/gnu/system.scm
@@ -110,6 +110,7 @@ (define-module (gnu system)
operating-system-default-label
operating-system-initrd-modules
operating-system-initrd
+ operating-system-initrd-file
operating-system-users
operating-system-groups
operating-system-issue
@@ -119,6 +120,7 @@ (define-module (gnu system)
operating-system-locale-libcs
operating-system-mapped-devices
operating-system-file-systems
+ operating-system-root-file-system
operating-system-store-file-system
operating-system-user-mapped-devices
operating-system-boot-mapped-devices
@@ -1355,7 +1357,7 @@ (define (operating-system-root-file-system os)
(location (operating-system-location os)))))))
(define (operating-system-initrd-file os)
- "Return a gexp denoting the initrd file of OS."
+ "Return a file-like object for the initrd file of OS."
(define boot-file-systems
(filter file-system-needed-for-boot?
(operating-system-file-systems os)))
--
2.46.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [bug#75027] [PATCH 3/3] reconfigure: Call ‘kexec-load-file’.
2024-12-22 15:56 [bug#75027] [PATCH 0/3] 'guix system reconfigure' loads system for kexec reboot Ludovic Courtès
2024-12-22 15:57 ` [bug#75027] [PATCH 1/3] syscalls: Add ‘kexec-load-file’ Ludovic Courtès
2024-12-22 15:57 ` [bug#75027] [PATCH 2/3] system: Export ‘…-initrd-file’ and ‘…-root-file-system’ Ludovic Courtès
@ 2024-12-22 15:57 ` Ludovic Courtès
2024-12-22 21:47 ` [bug#75027] [PATCH 0/3] 'guix system reconfigure' loads system for kexec reboot Jakob Kirsch via Guix-patches via
3 siblings, 0 replies; 5+ messages in thread
From: Ludovic Courtès @ 2024-12-22 15:57 UTC (permalink / raw)
To: 75027
Cc: Ludovic Courtès, Christopher Baines, Josselin Poiret,
Ludovic Courtès, Mathieu Othacehe, Simon Tournier,
Tobias Geerinckx-Rice
This allows rebooting straight into the new system with ‘reboot -k’.
* guix/scripts/system/reconfigure.scm (kexec-loading-program): New
procedure.
(upgrade-shepherd-services): Use it.
* gnu/tests/reconfigure.scm (run-kexec-test): New procedure.
(%test-upgrade-kexec): New variable.
Change-Id: I86d11f1c348e4359bc9e73c86e5aebff60fe875c
---
gnu/tests/reconfigure.scm | 77 +++++++++++++++++++++++++++++
guix/scripts/system/reconfigure.scm | 25 ++++++++++
2 files changed, 102 insertions(+)
diff --git a/gnu/tests/reconfigure.scm b/gnu/tests/reconfigure.scm
index bcc7645fa3..8d33bdac9b 100644
--- a/gnu/tests/reconfigure.scm
+++ b/gnu/tests/reconfigure.scm
@@ -1,5 +1,6 @@
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2019 Jakob L. Kreuze <zerodaysfordays@sdf.org>
+;;; Copyright © 2024 Ludovic Courtès <ludo@gnu.org>
;;;
;;; This file is part of GNU Guix.
;;;
@@ -18,9 +19,12 @@
(define-module (gnu tests reconfigure)
#:use-module (gnu bootloader)
+ #:use-module (gnu services)
+ #:use-module (gnu services base)
#:use-module (gnu services shepherd)
#:use-module (gnu system)
#:use-module (gnu system accounts)
+ #:use-module (gnu system file-systems)
#:use-module (gnu system shadow)
#:use-module (gnu system vm)
#:use-module (gnu tests)
@@ -31,6 +35,7 @@ (define-module (gnu tests reconfigure)
#:use-module (guix store)
#:export (%test-switch-to-system
%test-upgrade-services
+ %test-upgrade-kexec
%test-install-bootloader))
;;; Commentary:
@@ -178,6 +183,72 @@ (define* (run-upgrade-services-test)
(disable (upgrade-services-program '() '() '(dummy) '())))
(test enable disable))))
+(define* (run-kexec-test)
+ (define os
+ (marionette-operating-system
+ (operating-system
+ (inherit %simple-os)
+ (services (modify-services %base-services
+ (syslog-service-type
+ config => (syslog-configuration
+ (inherit config)
+ (config-file
+ (plain-file
+ "syslog.conf"
+ "*.* /dev/console\n")))))))
+ #:imported-modules '((gnu services herd)
+ (guix combinators))))
+
+ (define new-os
+ (marionette-operating-system
+ (virtualized-operating-system ;run as with "guix system vm"
+ (operating-system
+ (inherit %simple-os)
+ (host-name "the-new-os")
+ (kernel-arguments '("console=ttyS0"))) ;be verbose
+ #:volatile? #t) ;mount root read-only
+ #:imported-modules '((gnu services herd)
+ (guix combinators))))
+
+ (define vm (virtual-machine os))
+
+ (define test
+ (with-imported-modules '((gnu build marionette))
+ #~(begin
+ (use-modules (gnu build marionette)
+ (srfi srfi-64))
+
+ (define marionette
+ (make-marionette (list #$vm)))
+
+ (test-runner-current (system-test-runner #$output))
+ (test-begin "kexec")
+
+ (test-equal "host name"
+ #$(operating-system-host-name os)
+ (marionette-eval '(gethostname) marionette))
+
+ (test-assert "kexec-loading-program"
+ (marionette-eval
+ '(primitive-load #$(kexec-loading-program new-os))
+ marionette))
+
+ (test-assert "reboot/kexec"
+ (marionette-eval
+ '(begin
+ (use-modules (gnu services herd))
+ (with-shepherd-action 'root ('kexec) result
+ (pk 'reboot-kexec result)))
+ marionette))
+
+ (test-equal "host name of new OS"
+ #$(operating-system-host-name new-os)
+ (marionette-eval '(gethostname) marionette))
+
+ (test-end))))
+
+ (gexp->derivation "kexec-test" test))
+
(define* (run-install-bootloader-test)
"Run a test of an OS running INSTALL-BOOTLOADER-PROGRAM, which installs a
bootloader's configuration file."
@@ -268,6 +339,12 @@ (define %test-upgrade-services
loading new services.")
(value (run-upgrade-services-test))))
+(define %test-upgrade-kexec
+ (system-test
+ (name "upgrade-kexec")
+ (description "FIXME")
+ (value (run-kexec-test))))
+
(define %test-install-bootloader
(system-test
(name "install-bootloader")
diff --git a/guix/scripts/system/reconfigure.scm b/guix/scripts/system/reconfigure.scm
index ddb561d28c..9e08179613 100644
--- a/guix/scripts/system/reconfigure.scm
+++ b/guix/scripts/system/reconfigure.scm
@@ -31,6 +31,7 @@ (define-module (guix scripts system reconfigure)
#:use-module (gnu services herd)
#:use-module (gnu services shepherd)
#:use-module (gnu system)
+ #:autoload (gnu system file-systems) (file-system-device)
#:use-module (guix gexp)
#:use-module (guix modules)
#:use-module (guix monads)
@@ -51,6 +52,7 @@ (define-module (guix scripts system reconfigure)
upgrade-services-program
upgrade-shepherd-services
+ kexec-loading-program
install-bootloader-program
install-bootloader
@@ -176,6 +178,27 @@ (define (upgrade-services-program service-files to-start to-unload to-restart)
(for-each unload-service '#$to-unload)
(for-each start-service '#$to-start)))))
+(define (kexec-loading-program os)
+ "Return a program that calls 'kexec_file_load' to allow rebooting into OS
+via 'kexec'."
+ (let ((root-device (file-system-device
+ (operating-system-root-file-system os))))
+ (program-file
+ "kexec-load-system.scm"
+ (with-imported-modules '((guix build syscalls))
+ #~(begin
+ (use-modules (guix build syscalls))
+
+ (let ((kernel (open-fdes #$(operating-system-kernel-file os)
+ O_RDONLY))
+ (initrd (open-fdes #$(operating-system-initrd-file os)
+ O_RDONLY)))
+ (kexec-load-file kernel initrd
+ (string-join
+ (list #$@(operating-system-kernel-arguments
+ os root-device)))
+ KEXEC_FILE_DEBUG)))))))
+
(define* (upgrade-shepherd-services eval os)
"Using EVAL, a monadic procedure taking a single G-Expression as an argument,
upgrade the Shepherd (PID 1) by unloading obsolete services and loading new
@@ -200,6 +223,8 @@ (define* (upgrade-shepherd-services eval os)
running))
(service-files (map shepherd-service-file target-services)))
(eval #~(parameterize ((current-warning-port (%make-void-port "w")))
+ (when (string-contains %host-type "-linux")
+ (primitive-load #$(kexec-loading-program os)))
(primitive-load #$(upgrade-services-program service-files
to-start
to-unload
--
2.46.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [bug#75027] [PATCH 0/3] 'guix system reconfigure' loads system for kexec reboot
2024-12-22 15:56 [bug#75027] [PATCH 0/3] 'guix system reconfigure' loads system for kexec reboot Ludovic Courtès
` (2 preceding siblings ...)
2024-12-22 15:57 ` [bug#75027] [PATCH 3/3] reconfigure: Call ‘kexec-load-file’ Ludovic Courtès
@ 2024-12-22 21:47 ` Jakob Kirsch via Guix-patches via
3 siblings, 0 replies; 5+ messages in thread
From: Jakob Kirsch via Guix-patches via @ 2024-12-22 21:47 UTC (permalink / raw)
To: Ludovic Courtès; +Cc: 75027
Would it be possible to expose the output of kexec-loading-program as a file in the output directory of the operating system (e.g. as /run/current-system/kexec)?
^ permalink raw reply [flat|nested] 5+ messages in thread
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2024-12-22 15:57 ` [bug#75027] [PATCH 3/3] reconfigure: Call ‘kexec-load-file’ Ludovic Courtès
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