From patchwork Wed Apr 17 10:40:43 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Babis Chalios X-Patchwork-Id: 789468 Received: from smtp-fw-80008.amazon.com (smtp-fw-80008.amazon.com [99.78.197.219]) (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 53F9E13C679; Wed, 17 Apr 2024 10:42:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=99.78.197.219 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713350538; cv=none; b=RM8HqHhp7ddGI+IjMRJNe8XnvERRJlgDX6GYg5dlJ/W0JlilYqWQG4bdIesw8Y+7dTdx36K3ny36wW8fjr/pKKZfDGnEuVzM/80+iHvT9SSFGzv6aPzYEC52atZUlR1DZifioknLFYkpOQksqULCvnTJUILUaQQ3AkT8VMvF+1A= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713350538; c=relaxed/simple; bh=w6juo0MjmFUn9ztBY4kfUx8g9rHFcR0V1lypBjU9/dg=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=CdazL4HmGKHFqZd5JouxR710BKKXnpSnNQvYuDSmPl6Nd8WoItOtywt0gR9qAc2zYWdIijoQ5x1qmVK8eI93OnA/Wk02D+qajwmkTmcMqCNlBeUrc15eqjMiAPTify5uNIjawJG/wGaLpKZx/zWPo3Wi3LJZlkrUM+MelhegbCI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.es; spf=pass smtp.mailfrom=amazon.es; dkim=pass (1024-bit key) header.d=amazon.es header.i=@amazon.es header.b=qecQsEqq; arc=none smtp.client-ip=99.78.197.219 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.es Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=amazon.es Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=amazon.es header.i=@amazon.es header.b="qecQsEqq" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.es; i=@amazon.es; q=dns/txt; s=amazon201209; t=1713350537; x=1744886537; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=me+iH+3ZKIOFJvRC7r+x77iYDHFJHkAOYcVbZdp3q/g=; b=qecQsEqqzWrJdPdhRik9HYsX7rlPy3KfGPcbq/8Ce7L5WutHetI2gU1t V+GSYyizTllYvQ2v88YZqkkVJJIDhDkfcPgAwLakpdUOAGiugjflF1HZh uQlGeiYFKwKwL9YzyflZoZ9W38z6vVR4MrODTwWn7JGinUZ6l7AE7OU3a s=; X-IronPort-AV: E=Sophos;i="6.07,209,1708387200"; d="scan'208";a="81958131" Received: from pdx4-co-svc-p1-lb2-vlan3.amazon.com (HELO smtpout.prod.us-east-1.prod.farcaster.email.amazon.dev) ([10.25.36.214]) by smtp-border-fw-80008.pdx80.corp.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Apr 2024 10:42:14 +0000 Received: from EX19MTAEUC001.ant.amazon.com [10.0.17.79:37894] by smtpin.naws.eu-west-1.prod.farcaster.email.amazon.dev [10.0.5.68:2525] with esmtp (Farcaster) id 68181eed-a4a4-48e3-a5e7-993b8cc1a4e1; Wed, 17 Apr 2024 10:42:13 +0000 (UTC) X-Farcaster-Flow-ID: 68181eed-a4a4-48e3-a5e7-993b8cc1a4e1 Received: from EX19D037EUB003.ant.amazon.com (10.252.61.119) by EX19MTAEUC001.ant.amazon.com (10.252.51.155) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1258.28; Wed, 17 Apr 2024 10:42:13 +0000 Received: from f4d4887fdcfb.ant.amazon.com (10.106.83.20) by EX19D037EUB003.ant.amazon.com (10.252.61.119) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1258.28; Wed, 17 Apr 2024 10:42:07 +0000 From: Babis Chalios To: , , , , , , , , , CC: , , , , , Alexander Graf Subject: [PATCH v6 2/5] virt: vmgenid: change implementation to use a platform driver Date: Wed, 17 Apr 2024 12:40:43 +0200 Message-ID: <20240417104046.27253-3-bchalios@amazon.es> X-Mailer: git-send-email 2.39.3 (Apple Git-145) In-Reply-To: <20240417104046.27253-1-bchalios@amazon.es> References: <20240417104046.27253-1-bchalios@amazon.es> Precedence: bulk X-Mailing-List: linux-crypto@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: EX19D041UWA003.ant.amazon.com (10.13.139.105) To EX19D037EUB003.ant.amazon.com (10.252.61.119) Re-implement vmgenid as a platform driver in preparation for adding devicetree bindings support in next commits. Co-authored-by: Sudan Landge Signed-off-by: Babis Chalios Reviewed-by: Alexander Graf --- drivers/virt/vmgenid.c | 97 +++++++++++++++++++++++++++++------------- 1 file changed, 67 insertions(+), 30 deletions(-) diff --git a/drivers/virt/vmgenid.c b/drivers/virt/vmgenid.c index a167ccfad299..c028e2064fdd 100644 --- a/drivers/virt/vmgenid.c +++ b/drivers/virt/vmgenid.c @@ -7,9 +7,10 @@ * information to random.c. */ +#include #include #include -#include +#include #include ACPI_MODULE_NAME("vmgenid"); @@ -21,9 +22,9 @@ struct vmgenid_state { u8 this_id[VMGENID_SIZE]; }; -static void vmgenid_notify(struct acpi_device *device, u32 event) +static void vmgenid_notify(struct device *device) { - struct vmgenid_state *state = acpi_driver_data(device); + struct vmgenid_state *state = device->driver_data; char *envp[] = { "NEW_VMGENID=1", NULL }; u8 old_id[VMGENID_SIZE]; @@ -32,21 +33,36 @@ static void vmgenid_notify(struct acpi_device *device, u32 event) if (!memcmp(old_id, state->this_id, sizeof(old_id))) return; add_vmfork_randomness(state->this_id, sizeof(state->this_id)); - kobject_uevent_env(&device->dev.kobj, KOBJ_CHANGE, envp); + kobject_uevent_env(&device->kobj, KOBJ_CHANGE, envp); +} + +static void vmgenid_acpi_handler(acpi_handle __always_unused handle, + u32 __always_unused event, void *dev) +{ + vmgenid_notify(dev); +} + +static int setup_vmgenid_state(struct vmgenid_state *state, u8 *next_id) +{ + if (IS_ERR(next_id)) + return PTR_ERR(next_id); + + state->next_id = next_id; + memcpy(state->this_id, state->next_id, sizeof(state->this_id)); + add_device_randomness(state->this_id, sizeof(state->this_id)); + return 0; } -static int vmgenid_add(struct acpi_device *device) +static int vmgenid_add_acpi(struct device *dev, + struct vmgenid_state *state) { + struct acpi_device *device = ACPI_COMPANION(dev); struct acpi_buffer parsed = { ACPI_ALLOCATE_BUFFER }; - struct vmgenid_state *state; union acpi_object *obj; phys_addr_t phys_addr; acpi_status status; int ret = 0; - - state = devm_kmalloc(&device->dev, sizeof(*state), GFP_KERNEL); - if (!state) - return -ENOMEM; + u8 *virt_addr; status = acpi_evaluate_object(device->handle, "ADDR", NULL, &parsed); if (ACPI_FAILURE(status)) { @@ -63,40 +79,61 @@ static int vmgenid_add(struct acpi_device *device) phys_addr = (obj->package.elements[0].integer.value << 0) | (obj->package.elements[1].integer.value << 32); - state->next_id = devm_memremap(&device->dev, phys_addr, VMGENID_SIZE, MEMREMAP_WB); - if (IS_ERR(state->next_id)) { - ret = PTR_ERR(state->next_id); + + virt_addr = (u8 *)devm_memremap(&device->dev, phys_addr, + VMGENID_SIZE, MEMREMAP_WB); + ret = setup_vmgenid_state(state, virt_addr); + if (ret) + goto out; + + dev->driver_data = state; + status = acpi_install_notify_handler(device->handle, ACPI_DEVICE_NOTIFY, + vmgenid_acpi_handler, dev); + if (ACPI_FAILURE(status)) { + dev_err(dev, "Failed to install acpi notify handler"); + ret = -ENODEV; + dev->driver_data = NULL; goto out; } +out: + ACPI_FREE(parsed.pointer); + return ret; +} - memcpy(state->this_id, state->next_id, sizeof(state->this_id)); - add_device_randomness(state->this_id, sizeof(state->this_id)); +static int vmgenid_add(struct platform_device *pdev) +{ + struct vmgenid_state *state; + struct device *dev = &pdev->dev; + int ret = 0; - device->driver_data = state; + state = devm_kmalloc(dev, sizeof(*state), GFP_KERNEL); + if (!state) + return -ENOMEM; + + ret = vmgenid_add_acpi(dev, state); + + if (ret) + devm_kfree(dev, state); -out: - ACPI_FREE(parsed.pointer); return ret; } -static const struct acpi_device_id vmgenid_ids[] = { +static const struct acpi_device_id vmgenid_acpi_ids[] = { { "VMGENCTR", 0 }, { "VM_GEN_COUNTER", 0 }, { } }; -MODULE_DEVICE_TABLE(acpi, vmgenid_ids); - -static struct acpi_driver vmgenid_driver = { - .name = "vmgenid", - .ids = vmgenid_ids, - .owner = THIS_MODULE, - .ops = { - .add = vmgenid_add, - .notify = vmgenid_notify - } +MODULE_DEVICE_TABLE(acpi, vmgenid_acpi_ids); + +static struct platform_driver vmgenid_plaform_driver = { + .probe = vmgenid_add, + .driver = { + .name = "vmgenid", + .acpi_match_table = vmgenid_acpi_ids, + }, }; -module_acpi_driver(vmgenid_driver); +module_platform_driver(vmgenid_plaform_driver) MODULE_DESCRIPTION("Virtual Machine Generation ID"); MODULE_LICENSE("GPL v2"); From patchwork Wed Apr 17 10:40:45 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Babis Chalios X-Patchwork-Id: 789467 Received: from smtp-fw-52002.amazon.com (smtp-fw-52002.amazon.com [52.119.213.150]) (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 DE25513C818; Wed, 17 Apr 2024 10:42:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=52.119.213.150 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713350575; cv=none; b=RCeP4ZmJyhwnpKcBSx/RQarVGcj22WgeXKkagZDedxWd1y+gfVcu/PJAdr1fqEOMhsUj7Zw0PI6/D6W/pFZJwdAaPEzf1sL9RiculOe+iB5lJb4hyVDkNFiM8LNaP6YdaOUF8hEd8CDpSOpo7oxiB95mDHn1CA6eySxvZKGpP6g= ARC-Message-Signature: i=1; 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Wed, 17 Apr 2024 10:42:49 +0000 Received: from f4d4887fdcfb.ant.amazon.com (10.106.83.20) by EX19D037EUB003.ant.amazon.com (10.252.61.119) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1258.28; Wed, 17 Apr 2024 10:42:44 +0000 From: Babis Chalios To: , , , , , , , , , CC: , , , , , Alexander Graf Subject: [PATCH v6 4/5] dt-bindings: rng: Add vmgenid support Date: Wed, 17 Apr 2024 12:40:45 +0200 Message-ID: <20240417104046.27253-5-bchalios@amazon.es> X-Mailer: git-send-email 2.39.3 (Apple Git-145) In-Reply-To: <20240417104046.27253-1-bchalios@amazon.es> References: <20240417104046.27253-1-bchalios@amazon.es> Precedence: bulk X-Mailing-List: linux-crypto@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: EX19D041UWA003.ant.amazon.com (10.13.139.105) To EX19D037EUB003.ant.amazon.com (10.252.61.119) Virtual Machine Generation ID driver was introduced in commit af6b54e2b5ba ("virt: vmgenid: notify RNG of VM fork and supply generation ID"), as an ACPI only device. VMGenID specification http://go.microsoft.com/fwlink/?LinkId=260709 defines a mechanism for the BIOS/hypervisors to communicate to the virtual machine that it is executed with a different configuration (e.g. snapshot execution or creation from a template). The guest operating system can use the notification for various purposes such as re-initializing its random number generator etc. As per the specs, hypervisor should provide a globally unique identified, or GUID via ACPI. This patch tries to mimic the mechanism to provide the same functionality which is for a hypervisor/BIOS to notify the virtual machine when it is executed with a different configuration. As part of this support the devicetree bindings requires the hypervisors or BIOS to provide a memory address which holds the GUID and an IRQ which is used to notify when there is a change in the GUID. The memory exposed in the DT should follow the rules defined in the vmgenid spec mentioned above. *Reason for this change*: Chosing ACPI or devicetree is an intrinsic part of an hypervisor design. Without going into details of why a hypervisor would chose DT over ACPI, we would like to highlight that the hypervisors that have chose devicetree and now want to make use of the vmgenid functionality cannot do so today because vmgenid is an ACPI only device. This forces these hypervisors to change their design which could have undesirable impacts on their use-cases, test-scenarios etc. The point of vmgenid is to provide a mechanism to discover a GUID when the execution state of a virtual machine changes and the simplest way to do it is pass a memory location and an interrupt via devicetree. It would complicate things unnecessarily if instead of using devicetree, we try to implement a new protocol or modify other protocols to somehow provide the same functionility. We believe that adding a devicetree binding for vmgenid is a simpler, better alternative to provide the same functionality and will allow such hypervisors as mentioned above to continue using devicetree. More references to vmgenid specs: - https://www.qemu.org/docs/master/specs/vmgenid.html - https://learn.microsoft.com/en-us/windows/win32/hyperv_v2/virtual- machine-generation-identifier Co-authored-by: Sudan Landge Signed-off-by: Babis Chalios Reviewed-by: Rob Herring Reviewed-by: Alexander Graf --- .../bindings/rng/microsoft,vmgenid.yaml | 49 +++++++++++++++++++ MAINTAINERS | 1 + 2 files changed, 50 insertions(+) create mode 100644 Documentation/devicetree/bindings/rng/microsoft,vmgenid.yaml diff --git a/Documentation/devicetree/bindings/rng/microsoft,vmgenid.yaml b/Documentation/devicetree/bindings/rng/microsoft,vmgenid.yaml new file mode 100644 index 000000000000..8f20dee93e7e --- /dev/null +++ b/Documentation/devicetree/bindings/rng/microsoft,vmgenid.yaml @@ -0,0 +1,49 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/rng/microsoft,vmgenid.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Virtual Machine Generation ID + +maintainers: + - Jason A. Donenfeld + +description: + Firmwares or hypervisors can use this devicetree to describe an + interrupt and a shared resource to inject a Virtual Machine Generation ID. + Virtual Machine Generation ID is a globally unique identifier (GUID) and + the devicetree binding follows VMGenID specification defined in + http://go.microsoft.com/fwlink/?LinkId=260709. + +properties: + compatible: + const: microsoft,vmgenid + + reg: + description: + Specifies a 16-byte VMGenID in endianness-agnostic hexadecimal format. + maxItems: 1 + + interrupts: + description: + Interrupt used to notify that a new VMGenID is available. + maxItems: 1 + +required: + - compatible + - reg + - interrupts + +additionalProperties: false + +examples: + - | + #include + rng@80000000 { + compatible = "microsoft,vmgenid"; + reg = <0x80000000 0x1000>; + interrupts = ; + }; + +... diff --git a/MAINTAINERS b/MAINTAINERS index c23fda1aa1f0..efd8de759d95 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -18469,6 +18469,7 @@ M: "Theodore Ts'o" M: Jason A. Donenfeld S: Maintained T: git https://git.kernel.org/pub/scm/linux/kernel/git/crng/random.git +F: Documentation/devicetree/bindings/rng/microsoft,vmgenid.yaml F: drivers/char/random.c F: drivers/virt/vmgenid.c