From nobody Wed Dec 31 10:05:22 2025 Received: from todd.t-8ch.de (todd.t-8ch.de [159.69.126.157]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 535C3241E2 for ; Fri, 12 Apr 2024 06:26:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=159.69.126.157 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712903212; cv=none; b=E6ERa7bW5hEXNIE1KX+W/IOXCL598Ap9LtIOMGKLhVvwSeehdakdxqmuGtF+gbRqx4RcGqUCVUpjnGqcpeq4geSGCaiqUk476nqxR4CjtBPPjSWh5nE9+Ajjso7dd4CDnvWsL4L5QIkRvLxX0a7/+2/F3EAWoNsDjZP3AtHL/Vw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712903212; c=relaxed/simple; bh=sDNbtYIHNde4yzG+mtMhm+CHahPBxWrK+Dlok/Vea98=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=RQWZHYMIdGCBPiUkIXOEQZhaqFc3lPm+EyyDtTrjg4iVoOxju38MWzFegHSkVm87C8cTtXUrclg/XkhyaO5HN6X5Ye8KOv/B686PnG4QfDzYYNbUNbatbLriFcJRzR0RzysuF+LhBppWs7/8IZf1UiPrTsZO2zzusMwLzNYIQOc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=weissschuh.net; spf=pass smtp.mailfrom=weissschuh.net; dkim=pass (1024-bit key) header.d=weissschuh.net header.i=@weissschuh.net header.b=RiLQlRpp; arc=none smtp.client-ip=159.69.126.157 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=weissschuh.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=weissschuh.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=weissschuh.net header.i=@weissschuh.net header.b="RiLQlRpp" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=weissschuh.net; s=mail; t=1712903204; bh=sDNbtYIHNde4yzG+mtMhm+CHahPBxWrK+Dlok/Vea98=; h=From:Date:Subject:To:Cc:From; b=RiLQlRpps2T9fke3w6Z+3tl8V6PyZ+y5k0F+0wLS9m3R2YWj6Jav2aOFUCbeZfuCY Nn8Stg73mfG34a9r8OYh4Zt60IiGhdlejRLTkqaENnaaoylJODQrSWdDkz89gdvd/+ Ulij/frWTbxuXo43JIyNlzErgJiyI6JzIl3ruhPg= From: =?utf-8?q?Thomas_Wei=C3=9Fschuh?= Date: Fri, 12 Apr 2024 08:26:40 +0200 Subject: [PATCH v3] misc/pvpanic: add support for normal shutdowns Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20240412-pvpanic-shutdown-v3-1-c214e9873b3f@weissschuh.net> X-B4-Tracking: v=1; b=H4sIAB/UGGYC/33NQQ6CMBCF4auQrq3ptCUFV97DuChlsLMphELRE O5uIXGlcfm/ZL5ZWcSRMLJLsbIRE0XqQw51KpjzNjyQU5ubSSEVgNB8SIMN5Hj089T2S+BlZ1V lK1PbFlg+G0bs6HmQt3tuT3Hqx9fxIcG+/sEScOAlonF1o1AJuC5IMUbnZ38OOLFdTPKjaKFB/ lDkoZRaazCNA/OlbNv2BpfJIPf7AAAA To: Arnd Bergmann , Greg Kroah-Hartman Cc: linux-kernel@vger.kernel.org, =?utf-8?q?Thomas_Wei=C3=9Fschuh?= X-Mailer: b4 0.13.0 X-Developer-Signature: v=1; a=ed25519-sha256; t=1712903203; l=4209; i=linux@weissschuh.net; s=20221212; h=from:subject:message-id; bh=sDNbtYIHNde4yzG+mtMhm+CHahPBxWrK+Dlok/Vea98=; b=4YJRC57gy8imlh/CoUA02y9HpGnd1FsYP8tRND2I6cJb7HztQThDH7FdRI3HcDzne2ns6NPgU QQi3nDOVtsSDpMsCvh+v2RaFq0PxQqdW0elJbEXw0JDER1sWUvoAH6P X-Developer-Key: i=linux@weissschuh.net; a=ed25519; pk=KcycQgFPX2wGR5azS7RhpBqedglOZVgRPfdFSPB1LNw= Shutdown requests are normally hardware dependent. By extending pvpanic to also handle shutdown requests, guests can submit such requests with an easily implementable and cross-platform mechanism. Signed-off-by: Thomas Wei=C3=9Fschuh --- Changes in v3: - Really drop RFC status - Update link to current revision of qemu patchset - Link to v2: https://lore.kernel.org/r/20240412-pvpanic-shutdown-v2-1-5e54= 4417bc17@weissschuh.net Changes in v2: - Drop RFC status - Drop define from header file as it was submitted on its own - Handle disabling of handler through sysfs - Link to v1: https://lore.kernel.org/r/20231104-pvpanic-shutdown-v1-1-5ee7= c9b3e301@weissschuh.net --- This patch is based on char-misc/char-misc-testing as it depends on commit ad76f3e8f57c ("misc/pvpanic: add shutdown event definition") The corresponding patch to qemu has also been submitted[0]. General discussions about the feature should happen on the other thread. [0] https://lore.kernel.org/qemu-devel/20240323-pvpanic-shutdown-v7-0-4ac1f= d546d6f@t-8ch.de/ --- drivers/misc/pvpanic/pvpanic.c | 43 ++++++++++++++++++++++++++++++++++++++= +++- 1 file changed, 42 insertions(+), 1 deletion(-) diff --git a/drivers/misc/pvpanic/pvpanic.c b/drivers/misc/pvpanic/pvpanic.c index df3457ce1cb1..17c0eb549463 100644 --- a/drivers/misc/pvpanic/pvpanic.c +++ b/drivers/misc/pvpanic/pvpanic.c @@ -19,6 +19,7 @@ #include #include #include +#include #include #include #include @@ -35,6 +36,7 @@ struct pvpanic_instance { void __iomem *base; unsigned int capability; unsigned int events; + struct sys_off_handler *sys_off; struct list_head list; }; =20 @@ -78,6 +80,39 @@ static struct notifier_block pvpanic_panic_nb =3D { .priority =3D INT_MAX, }; =20 +static int pvpanic_sys_off(struct sys_off_data *data) +{ + pvpanic_send_event(PVPANIC_SHUTDOWN); + + return NOTIFY_DONE; +} + +static void pvpanic_synchronize_sys_off_handler(struct device *dev, struct= pvpanic_instance *pi) +{ + /* The kernel core has logic to fall back to system halt if no + * sys_off_handler is registered. + * When the pvpanic sys_off_handler is disabled via sysfs the kernel + * should use that fallback logic, so the handler needs to be unregistere= d. + */ + + struct sys_off_handler *sys_off; + + if (!(pi->events & PVPANIC_SHUTDOWN) =3D=3D !pi->sys_off) + return; + + if (!pi->sys_off) { + sys_off =3D register_sys_off_handler(SYS_OFF_MODE_POWER_OFF, SYS_OFF_PRI= O_LOW, + pvpanic_sys_off, NULL); + if (IS_ERR(sys_off)) + dev_warn(dev, "Could not register sys_off_handler: %pe\n", sys_off); + else + pi->sys_off =3D sys_off; + } else { + unregister_sys_off_handler(pi->sys_off); + pi->sys_off =3D NULL; + } +} + static void pvpanic_remove(void *param) { struct pvpanic_instance *pi_cur, *pi_next; @@ -91,6 +126,8 @@ static void pvpanic_remove(void *param) } } spin_unlock(&pvpanic_lock); + + unregister_sys_off_handler(pi->sys_off); } =20 static ssize_t capability_show(struct device *dev, struct device_attribute= *attr, char *buf) @@ -123,6 +160,7 @@ static ssize_t events_store(struct device *dev, struct = device_attribute *attr, return -EINVAL; =20 pi->events =3D tmp; + pvpanic_synchronize_sys_off_handler(dev, pi); =20 return count; } @@ -156,12 +194,15 @@ int devm_pvpanic_probe(struct device *dev, void __iom= em *base) return -ENOMEM; =20 pi->base =3D base; - pi->capability =3D PVPANIC_PANICKED | PVPANIC_CRASH_LOADED; + pi->capability =3D PVPANIC_PANICKED | PVPANIC_CRASH_LOADED | PVPANIC_SHUT= DOWN; =20 /* initlize capability by RDPT */ pi->capability &=3D ioread8(base); pi->events =3D pi->capability; =20 + pi->sys_off =3D NULL; + pvpanic_synchronize_sys_off_handler(dev, pi); + spin_lock(&pvpanic_lock); list_add(&pi->list, &pvpanic_list); spin_unlock(&pvpanic_lock); --- base-commit: dc806bd48abc1b8a4ae72709a37e65db42a32048 change-id: 20231104-pvpanic-shutdown-5fa38a879ad1 Best regards, --=20 Thomas Wei=C3=9Fschuh