From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 35C9215FA76; Thu, 18 Apr 2024 12:13:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713442416; cv=none; b=ni8+qd2W3oU1vCcKxoTaNLFEcU4fPkW8Opys+RHzoyONj+j65NEeRckQw8AEd3S6wuZegithRQe/Z2NQ9gb3pH1ZkaSVOQ3/pUEmT4Jvf9YkBdsAYNs/a++qvNELAAI8Wa8Wip1hRcw6J/2pm7zwPKpcOriwI1/3KjWjO08PaEk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713442416; c=relaxed/simple; bh=VQUJGeeRWUloAWWB1Hyejv1PGZzE7T5/iKqrDFVIZDo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=D56dhTwmbySM8wMF2qOLkmFdxUL/FS83wGAYs8ynkTZFdmNgcYVml7jo24ckJmzABvrcwO45gJam1B0pgAJL7f1JjEPgKUk5oL+JB1AerXctqGDK+KmYGgDOdctqKAE8I5+GLCEuOreA5hcNtlbeEJVNgSS0rZ7LJ+D/gtFHmgU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b=edwjgr6E; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="edwjgr6E" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A7BE6C2BD11; Thu, 18 Apr 2024 12:13:34 +0000 (UTC) Authentication-Results: smtp.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="edwjgr6E" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zx2c4.com; s=20210105; t=1713442413; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=aq6JxSnWT2dRtETeeOa/f63j90uhZ8kS0pFZ3RGL2y8=; b=edwjgr6EnEXfAJpSfhxKoISY47u6S9LNTNfxb7wqGAHku9KcROKgQty+HaL2+s5GqU7R5j OwO7vmerWfA+m5BQAX/n7leXDYH4JdcHWUAB9jj5blEJNGF/KfG3S4qsbcjvuP6jTVN1Tg Ok1fW9K6R/BZmkDK199QbBwZv00h+HE= Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id 81429b10 (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO); Thu, 18 Apr 2024 12:13:33 +0000 (UTC) From: "Jason A. Donenfeld" To: tytso@mit.edu, robh@kernel.org, krzk@kernel.org, conor+dt@kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, sudanl@amazon.com, graf@amazon.com, dwmw@amazon.co.uk, krzysztof.kozlowski@linaro.org Cc: "Jason A . Donenfeld" Subject: [PATCH v7 3/3] virt: vmgenid: add support for devicetree bindings Date: Thu, 18 Apr 2024 14:12:32 +0200 Message-ID: <20240418121249.42380-4-Jason@zx2c4.com> In-Reply-To: <20240418121249.42380-1-Jason@zx2c4.com> References: <20240418121249.42380-1-Jason@zx2c4.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Sudan Landge Extend the vmgenid platform driver to support devicetree bindings. With this support, hypervisors can send vmgenid notifications to the virtual machine without the need to enable ACPI. The bindings are located at: Documentation/devicetree/bindings/rng/microsoft,vmgenid.yaml Since this makes the driver work for both ACPI and devicetree, adjust the Kconfig to include `|| OF`, which in turn means accounting for !CONFIG_ACPI in the code with a short ifdef. Signed-off-by: Sudan Landge Reviewed-by: Alexander Graf [Jason: - Small style cleanups and refactoring. - Fold in Kconfig OF dependency and ACPI conditionalization. ] Signed-off-by: Jason A. Donenfeld --- drivers/virt/Kconfig | 2 +- drivers/virt/vmgenid.c | 53 ++++++++++++++++++++++++++++++++++++++++-- 2 files changed, 52 insertions(+), 3 deletions(-) diff --git a/drivers/virt/Kconfig b/drivers/virt/Kconfig index 40129b6f0eca..017d6c38c3ba 100644 --- a/drivers/virt/Kconfig +++ b/drivers/virt/Kconfig @@ -16,7 +16,7 @@ if VIRT_DRIVERS config VMGENID tristate "Virtual Machine Generation ID driver" default y - depends on ACPI + depends on ACPI || OF help Say Y here to use the hypervisor-provided Virtual Machine Generation ID to reseed the RNG when the VM is cloned. This is highly recommended if diff --git a/drivers/virt/vmgenid.c b/drivers/virt/vmgenid.c index aebbd24512c9..7f2d1e5656df 100644 --- a/drivers/virt/vmgenid.c +++ b/drivers/virt/vmgenid.c @@ -2,12 +2,13 @@ /* * Copyright (C) 2022 Jason A. Donenfeld . All Rights Reserved. * - * The "Virtual Machine Generation ID" is exposed via ACPI and changes when a + * The "Virtual Machine Generation ID" is exposed via ACPI or DT and changes when a * virtual machine forks or is cloned. This driver exists for shepherding that * information to random.c. */ #include +#include #include #include #include @@ -41,6 +42,7 @@ static void setup_vmgenid_state(struct vmgenid_state *state, void *virt_addr) add_device_randomness(state->this_id, sizeof(state->this_id)); } +#ifdef CONFIG_ACPI static void vmgenid_acpi_handler(acpi_handle __always_unused handle, u32 __always_unused event, void *dev) { @@ -92,6 +94,43 @@ static int vmgenid_add_acpi(struct device *dev, struct vmgenid_state *state) ACPI_FREE(parsed.pointer); return ret; } +#else +static int vmgenid_add_acpi(struct device *dev, struct vmgenid_state *state) +{ + return -EINVAL; +} +#endif + +static irqreturn_t vmgenid_of_irq_handler(int __always_unused irq, void *dev) +{ + vmgenid_notify(dev); + return IRQ_HANDLED; +} + +static int vmgenid_add_of(struct platform_device *pdev, + struct vmgenid_state *state) +{ + void *virt_addr; + int ret; + + virt_addr = devm_platform_get_and_ioremap_resource(pdev, 0, NULL); + if (IS_ERR(virt_addr)) + return PTR_ERR(virt_addr); + + setup_vmgenid_state(state, virt_addr); + + ret = platform_get_irq(pdev, 0); + if (ret) + return ret; + + ret = devm_request_irq(&pdev->dev, ret, vmgenid_of_irq_handler, + IRQF_SHARED, "vmgenid", &pdev->dev); + if (ret) + return ret; + + pdev->dev.driver_data = state; + return 0; +} static int vmgenid_add(struct platform_device *pdev) { @@ -103,13 +142,22 @@ static int vmgenid_add(struct platform_device *pdev) if (!state) return -ENOMEM; - ret = vmgenid_add_acpi(dev, state); + if (dev->of_node) + ret = vmgenid_add_of(pdev, state); + else + ret = vmgenid_add_acpi(dev, state); if (ret) devm_kfree(dev, state); return ret; } +static const struct of_device_id vmgenid_of_ids[] = { + { .compatible = "microsoft,vmgenid", }, + { }, +}; +MODULE_DEVICE_TABLE(of, vmgenid_of_ids); + static const struct acpi_device_id vmgenid_acpi_ids[] = { { "VMGENCTR", 0 }, { "VM_GEN_COUNTER", 0 }, @@ -122,6 +170,7 @@ static struct platform_driver vmgenid_plaform_driver = { .driver = { .name = "vmgenid", .acpi_match_table = vmgenid_acpi_ids, + .of_match_table = vmgenid_of_ids, }, }; -- 2.44.0