From patchwork Thu Jul 7 12:53:23 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Grzegorz Jaszczyk X-Patchwork-Id: 12909549 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 67215CCA482 for ; Thu, 7 Jul 2022 12:57:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235928AbiGGM5O (ORCPT ); Thu, 7 Jul 2022 08:57:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49020 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235348AbiGGM4w (ORCPT ); Thu, 7 Jul 2022 08:56:52 -0400 Received: from mail-lf1-x132.google.com (mail-lf1-x132.google.com [IPv6:2a00:1450:4864:20::132]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 44BD03192C for ; Thu, 7 Jul 2022 05:56:23 -0700 (PDT) Received: by mail-lf1-x132.google.com with SMTP id f39so30969067lfv.3 for ; Thu, 07 Jul 2022 05:56:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=semihalf.com; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=2+/ZVPt3U/lu0gkn4JYhnqM2dENcEUukg3rF+ztpMp8=; b=aiInV8wkI4Ru4vjyTWbX9ib5eRWxnEEjwhFJbYSIBg3CqX0ravkePdB9v+Onju0LVb K+eypJaNYPPgfOHCCII9hz0792sYA4Gu3Zxy6zRnPs/FQco7QEgMsBY4HjhmodJSkPW4 8h0Oq3lI6b7WbvVYEmUcXV0d5McEZvuHU5ZTWvxZNq4lTlI6iuu7teZtBlU4MrEI9SIm ij+p1IFQzpEq4J1SNAo8vpYGish6Yo4NGQFOi0m58CEuyrKCdzCwGACHr0eB382yHqxg qaIzhHmWTPrwq+0vIPgLCTFqMoRgG2H5Vuds/yvUU+ZIHXPBYgcgMUwnUZHPqhsPfXSs /Bng== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=2+/ZVPt3U/lu0gkn4JYhnqM2dENcEUukg3rF+ztpMp8=; b=D5wLjK1FHxJZohh+ya18fPG0I1UJsTOQwrsq2prU7gMFQup0NmB+7d5pfLbGj7bFxb C86CesOBI6iUAzugw7bD7n0JV6IBiqMLvjw0x9iy5U403hRy7wgxekBZ6lX7Ve6kaTTB awjosynTU2V7LKTHqLdUDi9PXT8LYIoi2mDqkgeRbh9cWn5OPfQHDhYL8rpa0Wbz1GVB 4AedyMryhwUgMu5erzr9oD/irKX2boYG42oLp2SvVX9pcEb0oGFHOSNKMoxtSqfgSQhF qCqVvk5Fpaf0v+RA11c/HeWpV0NpvCeS16D+Jg8JdKrp4W8M/jusPvhUrA1zu2p5L/H5 95Og== X-Gm-Message-State: AJIora/SheOKMrTZwcfSQ4Oao3I69xEQoySs89lVr6zuYmp87JzB6C8n 0rV0mDkG7l0ZSmtNF3Y9MftdbQ== X-Google-Smtp-Source: AGRyM1sQMa/AsCwWa2+anJrNkfAWw1jwy0vKBCC9ftMR04N4rDu7gPvhFPpIUWkxTvpiSPGpcyEIeQ== X-Received: by 2002:a05:6512:2a91:b0:47f:6e1d:d22c with SMTP id dt17-20020a0565122a9100b0047f6e1dd22cmr31529344lfb.550.1657198581450; Thu, 07 Jul 2022 05:56:21 -0700 (PDT) Received: from jazctssd.c.googlers.com.com (138.58.228.35.bc.googleusercontent.com. [35.228.58.138]) by smtp.gmail.com with ESMTPSA id d7-20020a05651221c700b0047255d2111csm6810361lft.75.2022.07.07.05.56.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 07 Jul 2022 05:56:20 -0700 (PDT) From: Grzegorz Jaszczyk To: linux-kernel@vger.kernel.org Cc: jaz@semihalf.com, dmy@semihalf.com, mario.limonciello@amd.com, seanjc@google.com, dbehr@google.com, upstream@semihalf.com, zide.chen@intel.corp-partner.google.com, "Rafael J. Wysocki" , Len Brown , Hans de Goede , Mark Gross , Pavel Machek , Mika Westerberg , Sachi King , linux-acpi@vger.kernel.org (open list:ACPI), platform-driver-x86@vger.kernel.org (open list:X86 PLATFORM DRIVERS), linux-pm@vger.kernel.org (open list:HIBERNATION (aka Software Suspend, aka swsusp)) Subject: [RFC PATCH 1/2] suspend: extend S2Idle ops by new notify handler Date: Thu, 7 Jul 2022 12:53:23 +0000 Message-Id: <20220707125329.378277-2-jaz@semihalf.com> X-Mailer: git-send-email 2.37.0.rc0.161.g10f37bed90-goog In-Reply-To: <20220707125329.378277-1-jaz@semihalf.com> References: <20220707125329.378277-1-jaz@semihalf.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Currently the LPS0 prepare_late callback is aimed to run as the very last thing before entering the S2Idle state from LPS0 perspective, nevertheless between this call and the system actually entering the S2Idle state there are several places where the suspension process could be canceled. In order to notify VMM about guest entering suspend, extend the S2Idle ops by new notify callback, which will be really invoked as a very last thing before guest actually enters S2Idle state. Additionally extend the acpi_s2idle_dev_ops by notify() callback so any driver can hook into it and allow to implement its own notification. Taking advantage of e.g. existing acpi_s2idle_dev_ops's prepare/restore hooks is not an option since it will not allow to prevent race conditions: - VM0 enters s2idle - host notes about VM0 is in s2idle - host continues with system suspension but in the meantime VM0 exits s2idle and sends notification but it is already too late (VM could not even send notification on time). Introducing notify() as a very last step before the system enters S2Idle together with an assumption that the VMM has control over guest resumption allows preventing mentioned races. Signed-off-by: Grzegorz Jaszczyk --- drivers/acpi/x86/s2idle.c | 11 +++++++++++ include/linux/acpi.h | 1 + include/linux/suspend.h | 1 + kernel/power/suspend.c | 4 ++++ 4 files changed, 17 insertions(+) diff --git a/drivers/acpi/x86/s2idle.c b/drivers/acpi/x86/s2idle.c index 2963229062f8..d5aff194c736 100644 --- a/drivers/acpi/x86/s2idle.c +++ b/drivers/acpi/x86/s2idle.c @@ -520,10 +520,21 @@ void acpi_s2idle_restore_early(void) lps0_dsm_func_mask, lps0_dsm_guid); } +static void acpi_s2idle_notify(void) +{ + struct acpi_s2idle_dev_ops *handler; + + list_for_each_entry(handler, &lps0_s2idle_devops_head, list_node) { + if (handler->notify) + handler->notify(); + } +} + static const struct platform_s2idle_ops acpi_s2idle_ops_lps0 = { .begin = acpi_s2idle_begin, .prepare = acpi_s2idle_prepare, .prepare_late = acpi_s2idle_prepare_late, + .notify = acpi_s2idle_notify, .wake = acpi_s2idle_wake, .restore_early = acpi_s2idle_restore_early, .restore = acpi_s2idle_restore, diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 4f82a5bc6d98..b32c4baed99b 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -1068,6 +1068,7 @@ struct acpi_s2idle_dev_ops { struct list_head list_node; void (*prepare)(void); void (*restore)(void); + void (*notify)(void); }; int acpi_register_lps0_dev(struct acpi_s2idle_dev_ops *arg); void acpi_unregister_lps0_dev(struct acpi_s2idle_dev_ops *arg); diff --git a/include/linux/suspend.h b/include/linux/suspend.h index 70f2921e2e70..16ef7f9d9a03 100644 --- a/include/linux/suspend.h +++ b/include/linux/suspend.h @@ -191,6 +191,7 @@ struct platform_s2idle_ops { int (*begin)(void); int (*prepare)(void); int (*prepare_late)(void); + void (*notify)(void); bool (*wake)(void); void (*restore_early)(void); void (*restore)(void); diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c index 827075944d28..6ba211b94ed1 100644 --- a/kernel/power/suspend.c +++ b/kernel/power/suspend.c @@ -100,6 +100,10 @@ static void s2idle_enter(void) /* Push all the CPUs into the idle loop. */ wake_up_all_idle_cpus(); + + if (s2idle_ops && s2idle_ops->notify) + s2idle_ops->notify(); + /* Make the current CPU wait so it can enter the idle loop too. */ swait_event_exclusive(s2idle_wait_head, s2idle_state == S2IDLE_STATE_WAKE); 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[35.228.58.138]) by smtp.gmail.com with ESMTPSA id d7-20020a05651221c700b0047255d2111csm6810361lft.75.2022.07.07.05.56.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 07 Jul 2022 05:56:28 -0700 (PDT) From: Grzegorz Jaszczyk To: linux-kernel@vger.kernel.org Cc: jaz@semihalf.com, dmy@semihalf.com, mario.limonciello@amd.com, seanjc@google.com, dbehr@google.com, upstream@semihalf.com, zide.chen@intel.corp-partner.google.com, "Rafael J. Wysocki" , Len Brown , Hans de Goede , Mark Gross , Pavel Machek , Sachi King , linux-acpi@vger.kernel.org (open list:ACPI), platform-driver-x86@vger.kernel.org (open list:X86 PLATFORM DRIVERS), linux-pm@vger.kernel.org (open list:SUSPEND TO RAM) Subject: [RFC PATCH 2/2] platform/x86: Add virtual PMC driver used for S2Idle Date: Thu, 7 Jul 2022 12:53:24 +0000 Message-Id: <20220707125329.378277-3-jaz@semihalf.com> X-Mailer: git-send-email 2.37.0.rc0.161.g10f37bed90-goog In-Reply-To: <20220707125329.378277-1-jaz@semihalf.com> References: <20220707125329.378277-1-jaz@semihalf.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Virtual PMC driver is meant for the guest VMs for the S2Idle notification. Its purpose is to register S2Idle dev ops notify handler, which will evaluate ACPI _DSM as a very last command before the guest enters S2Idle power state. This allows to trap on MMIO access done as a consequence of _DSM evaluation and therefore notify the VMM about the guest entering S2Idle state. Signed-off-by: Grzegorz Jaszczyk --- drivers/platform/x86/Kconfig | 7 ++++ drivers/platform/x86/Makefile | 1 + drivers/platform/x86/virt_pmc.c | 73 +++++++++++++++++++++++++++++++++ 3 files changed, 81 insertions(+) create mode 100644 drivers/platform/x86/virt_pmc.c diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig index bc4013e950ed..dee974321b01 100644 --- a/drivers/platform/x86/Kconfig +++ b/drivers/platform/x86/Kconfig @@ -479,6 +479,13 @@ config WIRELESS_HOTKEY To compile this driver as a module, choose M here: the module will be called wireless-hotkey. +config VIRT_PMC + tristate "Virt PMC" + depends on ACPI && SUSPEND + help + The Virtual PMC driver is meant for the guest VMs and it's main + purpose is to notify about guest entering s2idle state. + config HP_WMI tristate "HP WMI extras" depends on ACPI_WMI diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile index 4a59f47a46e2..3c3e440f11bb 100644 --- a/drivers/platform/x86/Makefile +++ b/drivers/platform/x86/Makefile @@ -116,6 +116,7 @@ obj-$(CONFIG_MLX_PLATFORM) += mlx-platform.o obj-$(CONFIG_TOUCHSCREEN_DMI) += touchscreen_dmi.o obj-$(CONFIG_WIRELESS_HOTKEY) += wireless-hotkey.o obj-$(CONFIG_X86_ANDROID_TABLETS) += x86-android-tablets.o +obj-$(CONFIG_VIRT_PMC) += virt_pmc.o # Intel uncore drivers obj-$(CONFIG_INTEL_IPS) += intel_ips.o diff --git a/drivers/platform/x86/virt_pmc.c b/drivers/platform/x86/virt_pmc.c new file mode 100644 index 000000000000..d0607db6cd22 --- /dev/null +++ b/drivers/platform/x86/virt_pmc.c @@ -0,0 +1,73 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Virtual Power Management Controller Driver + * + * Author: Grzegorz Jaszczyk + */ + +#include +#include + +#define ACPI_VIRT_PMC_DSM_UUID "9ea49ba3-434a-49a6-be30-37cc55c4d397" +#define ACPI_VIRT_PMC_NOTIFY 1 + +static acpi_handle virt_pmc_handle; + +static void virt_pmc_s2idle_notify(void) +{ + union acpi_object *out_obj; + static guid_t dsm_guid; + + guid_parse(ACPI_VIRT_PMC_DSM_UUID, &dsm_guid); + + out_obj = acpi_evaluate_dsm(virt_pmc_handle, &dsm_guid, + 0, ACPI_VIRT_PMC_NOTIFY, NULL); + + acpi_handle_debug(virt_pmc_handle, "_DSM function %u evaluation %s\n", + ACPI_VIRT_PMC_NOTIFY, out_obj ? "successful" : "failed"); + + ACPI_FREE(out_obj); +} + +static struct acpi_s2idle_dev_ops amd_pmc_s2idle_dev_ops = { + .notify = virt_pmc_s2idle_notify, +}; + +static int virt_pmc_probe(struct platform_device *pdev) +{ + int err = 0; + + virt_pmc_handle = ACPI_HANDLE(&pdev->dev); + + err = acpi_register_lps0_dev(&amd_pmc_s2idle_dev_ops); + if (err) + dev_warn(&pdev->dev, "failed to register LPS0 sleep handler\n"); + + return err; +} + +static int virt_pmc_remove(struct platform_device *pdev) +{ + acpi_unregister_lps0_dev(&amd_pmc_s2idle_dev_ops); + + return 0; +} + +static const struct acpi_device_id virt_pmc_acpi_ids[] = { + {"HYPE0001", 0}, /* _HID for XXX Power Engine, _CID PNP0D80*/ + { } +}; +MODULE_DEVICE_TABLE(acpi, virt_pmc_acpi_ids); + +static struct platform_driver virt_pmc_driver = { + .driver = { + .name = "virtual_pmc", + .acpi_match_table = ACPI_PTR(virt_pmc_acpi_ids), + }, + .probe = virt_pmc_probe, + .remove = virt_pmc_remove, +}; + +module_platform_driver(virt_pmc_driver); + +MODULE_DESCRIPTION("Virtual PMC Driver");