From nobody Sat May 18 07:08:58 2024 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 37DC313D88B; Fri, 19 Apr 2024 22:40:35 +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=1713566436; cv=none; b=CBAcecs92X9fHjXG963nfC2k3E0+Mc8qmoqov4Q/WpN6N7dJ7jfNg0yOQCpRAQOV8bhA4xTrYUG+Gr1EqOA9UiB0PlkhSIQlatiVfs4urHpVMJBgMiDCa1jjL6e9YjuQ4E6lH1XQ5yLYVljHRnZFjLcwEjry+IUHrMfbwYuOOOQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713566436; c=relaxed/simple; bh=KPPw/HKWprop8cnDRE1kdw35iiNxOd0n3PLh95dw2S8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=oiLhDm0UB3KCuE4Q0DAMF3TLDnEBnuys7offYxm5kOY9+40VgghGy8Ed0VQofYSWJB1R9CG5x8wliPw3zJQntJ4FonfXUkaCAC08EU8DQ3z9mD3US1GgywcAEoCmmYxozdzk98EFitjyYmNArjicxPXYTUFff4QPNGD3ltYw3U0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b=T8tHWS57; 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="T8tHWS57" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7CD3BC32782; Fri, 19 Apr 2024 22:40:34 +0000 (UTC) Authentication-Results: smtp.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="T8tHWS57" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zx2c4.com; s=20210105; t=1713566433; 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=KVXP/wNApq7zCtd4Du0Pp6Da0k1GBTT3HmGn81wuLF4=; b=T8tHWS5727tNHPdgtzaxG3vfT3gLWNuNkU+fz40Ooj5h0QPiRcO8JN8cOMeRQNkmyVNeCh il7LppOcNqcDXoCKaN0mrPFL/S3ZmbWgppmdumtBo2QoVkN0fhR9eJeMmZp2udem4I+qan Wxm8bujvyQ4Yrny1KhMJElsM4HZi3Mk= Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id e9df3a18 (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO); Fri, 19 Apr 2024 22:40:32 +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, bchalios@amazon.es Cc: "Jason A . Donenfeld" Subject: [PATCH v8 1/3] virt: vmgenid: change implementation to use a platform driver Date: Sat, 20 Apr 2024 00:39:58 +0200 Message-ID: <20240419224020.780377-2-Jason@zx2c4.com> In-Reply-To: <20240419224020.780377-1-Jason@zx2c4.com> References: <20240419224020.780377-1-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: quoted-printable Content-Type: text/plain; charset="utf-8" From: Sudan Landge Re-implement vmgenid as a platform driver in preparation for adding devicetree bindings support in next commits. Signed-off-by: Sudan Landge Reviewed-by: Alexander Graf [Jason: - Small style cleanups and refactoring.] Signed-off-by: Jason A. Donenfeld Tested-by: Babis Chalios --- drivers/virt/vmgenid.c | 99 +++++++++++++++++++++++++++--------------- 1 file changed, 65 insertions(+), 34 deletions(-) diff --git a/drivers/virt/vmgenid.c b/drivers/virt/vmgenid.c index a1c467a0e9f7..0522107f9bee 100644 --- a/drivers/virt/vmgenid.c +++ b/drivers/virt/vmgenid.c @@ -7,9 +7,10 @@ * information to random.c. */ =20 +#include #include #include -#include +#include #include =20 ACPI_MODULE_NAME("vmgenid"); @@ -21,19 +22,41 @@ struct vmgenid_state { u8 this_id[VMGENID_SIZE]; }; =20 -static int vmgenid_add(struct acpi_device *device) +static void vmgenid_notify(struct device *device) +{ + struct vmgenid_state *state =3D device->driver_data; + u8 old_id[VMGENID_SIZE]; + + memcpy(old_id, state->this_id, sizeof(old_id)); + memcpy(state->this_id, state->next_id, sizeof(state->this_id)); + if (!memcmp(old_id, state->this_id, sizeof(old_id))) + return; + add_vmfork_randomness(state->this_id, sizeof(state->this_id)); +} + +static void setup_vmgenid_state(struct vmgenid_state *state, void *virt_ad= dr) { + state->next_id =3D virt_addr; + memcpy(state->this_id, state->next_id, sizeof(state->this_id)); + add_device_randomness(state->this_id, sizeof(state->this_id)); +} + +static void vmgenid_acpi_handler(acpi_handle __always_unused handle, + u32 __always_unused event, void *dev) +{ + vmgenid_notify(dev); +} + +static int vmgenid_add_acpi(struct device *dev, struct vmgenid_state *stat= e) +{ + struct acpi_device *device =3D ACPI_COMPANION(dev); struct acpi_buffer parsed =3D { ACPI_ALLOCATE_BUFFER }; - struct vmgenid_state *state; union acpi_object *obj; phys_addr_t phys_addr; acpi_status status; + void *virt_addr; int ret =3D 0; =20 - state =3D devm_kmalloc(&device->dev, sizeof(*state), GFP_KERNEL); - if (!state) - return -ENOMEM; - status =3D acpi_evaluate_object(device->handle, "ADDR", NULL, &parsed); if (ACPI_FAILURE(status)) { ACPI_EXCEPTION((AE_INFO, status, "Evaluating ADDR")); @@ -49,53 +72,61 @@ static int vmgenid_add(struct acpi_device *device) =20 phys_addr =3D (obj->package.elements[0].integer.value << 0) | (obj->package.elements[1].integer.value << 32); - state->next_id =3D devm_memremap(&device->dev, phys_addr, VMGENID_SIZE, M= EMREMAP_WB); - if (IS_ERR(state->next_id)) { - ret =3D PTR_ERR(state->next_id); + + virt_addr =3D devm_memremap(&device->dev, phys_addr, VMGENID_SIZE, MEMREM= AP_WB); + if (IS_ERR(virt_addr)) { + ret =3D PTR_ERR(virt_addr); goto out; } + setup_vmgenid_state(state, virt_addr); =20 - memcpy(state->this_id, state->next_id, sizeof(state->this_id)); - add_device_randomness(state->this_id, sizeof(state->this_id)); - - device->driver_data =3D state; + status =3D acpi_install_notify_handler(device->handle, ACPI_DEVICE_NOTIFY, + vmgenid_acpi_handler, dev); + if (ACPI_FAILURE(status)) { + ret =3D -ENODEV; + goto out; + } =20 + dev->driver_data =3D state; out: ACPI_FREE(parsed.pointer); return ret; } =20 -static void vmgenid_notify(struct acpi_device *device, u32 event) +static int vmgenid_add(struct platform_device *pdev) { - struct vmgenid_state *state =3D acpi_driver_data(device); - u8 old_id[VMGENID_SIZE]; + struct device *dev =3D &pdev->dev; + struct vmgenid_state *state; + int ret; =20 - memcpy(old_id, state->this_id, sizeof(old_id)); - memcpy(state->this_id, state->next_id, sizeof(state->this_id)); - if (!memcmp(old_id, state->this_id, sizeof(old_id))) - return; - add_vmfork_randomness(state->this_id, sizeof(state->this_id)); + state =3D devm_kmalloc(dev, sizeof(*state), GFP_KERNEL); + if (!state) + return -ENOMEM; + + ret =3D vmgenid_add_acpi(dev, state); + + if (ret < 0) + devm_kfree(dev, state); + return ret; } =20 -static const struct acpi_device_id vmgenid_ids[] =3D { +static const struct acpi_device_id vmgenid_acpi_ids[] =3D { { "VMGENCTR", 0 }, { "VM_GEN_COUNTER", 0 }, { } }; - -static struct acpi_driver vmgenid_driver =3D { - .name =3D "vmgenid", - .ids =3D vmgenid_ids, - .owner =3D THIS_MODULE, - .ops =3D { - .add =3D vmgenid_add, - .notify =3D vmgenid_notify - } +MODULE_DEVICE_TABLE(acpi, vmgenid_acpi_ids); + +static struct platform_driver vmgenid_plaform_driver =3D { + .probe =3D vmgenid_add, + .driver =3D { + .name =3D "vmgenid", + .acpi_match_table =3D vmgenid_acpi_ids, + }, }; =20 -module_acpi_driver(vmgenid_driver); +module_platform_driver(vmgenid_plaform_driver) =20 -MODULE_DEVICE_TABLE(acpi, vmgenid_ids); MODULE_DESCRIPTION("Virtual Machine Generation ID"); MODULE_LICENSE("GPL v2"); MODULE_AUTHOR("Jason A. Donenfeld "); --=20 2.44.0 From nobody Sat May 18 07:08:58 2024 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 516CF13DB9B; Fri, 19 Apr 2024 22:40:39 +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=1713566439; cv=none; b=uSWz3xzmBivick1fM+CTsgeGJQGcWCEdo0YacfyITbicyfMYZEhWjZIluidX8TgVh/TToCwVL7tgMTBZz2vB7x0CNgR/nepkpTHboeQyIb7k3HYWk6joz2DQNpVZmXtT4MAo3I18FDGpdVSJXzR3UxLZzimC7vii20av9ad5pBo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713566439; c=relaxed/simple; bh=ErwPeRbH++s2//PbjnVZnkQnaI5e9Bqpjk54K44Qia0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Oq7btYAbudbXhF3TjSFxXiluXlKJFBLI/BH15bVJVgPg7nfx74q3HT0ASdnIQgMbcRtzUNrYdS99hK9mXZOODEnlezy1Y01ZTDQ1pY4iUad9roiHYG7/uq/3BIH1/54ufaeX6xKbs0Ad8tY/dNi881NYUmwyU+/7c6q67MoRcEE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b=gUeEFWlm; 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="gUeEFWlm" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EC67BC072AA; Fri, 19 Apr 2024 22:40:37 +0000 (UTC) Authentication-Results: smtp.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="gUeEFWlm" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zx2c4.com; s=20210105; t=1713566436; 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=Npv4DPrEoAcZpMwaWHoET4ASGglyUL7AxON3/pnPZ8s=; b=gUeEFWlm2J3Z/tmTyHFu6E9bAnrhl9C7FOnLRyqgkgwwb7l9M08Fqk8umm4kNRsp1dyEOx s60O2Z1C9JzVwK5UrrEeKHMVTJGdZpBsYT2d5tmUb/JMnWL8ppMOZar6g4913SIB4fzuBr IrQ1z62vQzaT+Ifa8dCfnyZp4Dhu6bU= Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id d83aadf2 (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO); Fri, 19 Apr 2024 22:40:36 +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, bchalios@amazon.es Cc: "Jason A . Donenfeld" Subject: [PATCH v8 2/3] dt-bindings: rng: Add vmgenid support Date: Sat, 20 Apr 2024 00:39:59 +0200 Message-ID: <20240419224020.780377-3-Jason@zx2c4.com> In-Reply-To: <20240419224020.780377-1-Jason@zx2c4.com> References: <20240419224020.780377-1-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: quoted-printable Content-Type: text/plain; charset="utf-8" From: Sudan Landge 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=3D260709 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 the vmgenid specs are found below. Signed-off-by: Sudan Landge Reviewed-by: Rob Herring Reviewed-by: Alexander Graf Link: https://www.qemu.org/docs/master/specs/vmgenid.html Link: https://learn.microsoft.com/en-us/windows/win32/hyperv_v2/virtual-mac= hine-generation-identifier Signed-off-by: Jason A. Donenfeld Tested-by: Babis Chalios --- .../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 I= D. + 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=3D260709. + +properties: + compatible: + const: microsoft,vmgenid + + reg: + description: + Specifies a 16-byte VMGenID in endianness-agnostic hexadecimal forma= t. + 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 =3D "microsoft,vmgenid"; + reg =3D <0x80000000 0x1000>; + interrupts =3D ; + }; + +... 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 =20 --=20 2.44.0 From nobody Sat May 18 07:08:58 2024 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 12D2213D639; Fri, 19 Apr 2024 22:40:42 +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=1713566443; cv=none; b=E860/gD0bnVVZzsSnibgeAlcFs2hiFnOp+jbO1MuNVkmxXHARwOAEwlZz6p2P7elx67xwjEQ7UblIoHXz5nacnFGEE+e2Cto0GxswyRzTdcPwh5qyZpJbP4USBQPhprWBerLz0NW4Gzr3+MHujrmjjcnS1EDomI/ldRx/hrjHcU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713566443; c=relaxed/simple; bh=CLOSPTOvgCa1gghsKOluMZpqjOL84fE+IgjLYFTiloc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=t0rOVsHILTITjz0KujELw3nuJqaj7HRkTFz/BoOzZJ/PZyDAuq55ZF5dR3blhtizgCtbcd/uTmLD/GPJwavoeUBNQcMCdsFw7bFF/hdpgnZLUexZv/ZUbpukhlI9I7bSUm+tci/Fp0XA4/qTw6hiAopDJXt+JIjPZhYttE6UFH0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b=keGV/MMs; 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="keGV/MMs" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 65D7FC116B1; Fri, 19 Apr 2024 22:40:41 +0000 (UTC) Authentication-Results: smtp.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="keGV/MMs" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zx2c4.com; s=20210105; t=1713566440; 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=r1N6bJmpLXPntAJnUgAgfuW02Wzo9jdJftZihclYhBg=; b=keGV/MMscXm++2gDXDfH7LnKkO9scwzdqrQM5xVDzkOALsrorvavAWCByBBqOL9GXpt4fb ZbCmh33zf8VBF1Ht5NcBjky1dxW9M5ZhgIEW6KJHZnHZcc6mJe35doa4isiG0ztw1hZCou 5UCPGosTnn5vJ9kyOtN7Nmjiypl/FB8= Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id 455959d4 (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO); Fri, 19 Apr 2024 22:40:39 +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, bchalios@amazon.es Cc: "Jason A . Donenfeld" Subject: [PATCH v8 3/3] virt: vmgenid: add support for devicetree bindings Date: Sat, 20 Apr 2024 00:40:00 +0200 Message-ID: <20240419224020.780377-4-Jason@zx2c4.com> In-Reply-To: <20240419224020.780377-1-Jason@zx2c4.com> References: <20240419224020.780377-1-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: quoted-printable Content-Type: text/plain; charset="utf-8" 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 is no longer ACPI-dependent, remove the dependency from Kconfig and protect the ACPI code with a single ifdef. Signed-off-by: Sudan Landge Reviewed-by: Alexander Graf [Jason: - Small style cleanups and refactoring. - Re-work ACPI conditionalization. ] Signed-off-by: Jason A. Donenfeld Tested-by: Babis Chalios --- drivers/virt/Kconfig | 1 - drivers/virt/vmgenid.c | 53 ++++++++++++++++++++++++++++++++++++++++-- 2 files changed, 51 insertions(+), 3 deletions(-) diff --git a/drivers/virt/Kconfig b/drivers/virt/Kconfig index 40129b6f0eca..d8c848cf09a6 100644 --- a/drivers/virt/Kconfig +++ b/drivers/virt/Kconfig @@ -16,7 +16,6 @@ if VIRT_DRIVERS config VMGENID tristate "Virtual Machine Generation ID driver" default y - depends on ACPI 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 0522107f9bee..66135eac3abf 100644 --- a/drivers/virt/vmgenid.c +++ b/drivers/virt/vmgenid.c @@ -2,12 +2,13 @@ /* * Copyright (C) 2022 Jason A. Donenfeld . All Rights Res= erved. * - * The "Virtual Machine Generation ID" is exposed via ACPI and changes whe= n a + * The "Virtual Machine Generation ID" is exposed via ACPI or DT and chang= es when a * virtual machine forks or is cloned. This driver exists for shepherding = that * information to random.c. */ =20 #include +#include #include #include #include @@ -41,6 +42,7 @@ static void setup_vmgenid_state(struct vmgenid_state *sta= te, void *virt_addr) add_device_randomness(state->this_id, sizeof(state->this_id)); } =20 +#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 v= mgenid_state *state) ACPI_FREE(parsed.pointer); return ret; } +#else +static int vmgenid_add_acpi(struct device *dev, struct vmgenid_state *stat= e) +{ + return -EINVAL; +} +#endif + +static irqreturn_t vmgenid_of_irq_handler(int __always_unused irq, void *d= ev) +{ + 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 =3D 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 =3D platform_get_irq(pdev, 0); + if (ret < 0) + return ret; + + ret =3D devm_request_irq(&pdev->dev, ret, vmgenid_of_irq_handler, + IRQF_SHARED, "vmgenid", &pdev->dev); + if (ret < 0) + return ret; + + pdev->dev.driver_data =3D state; + return 0; +} =20 static int vmgenid_add(struct platform_device *pdev) { @@ -103,13 +142,22 @@ static int vmgenid_add(struct platform_device *pdev) if (!state) return -ENOMEM; =20 - ret =3D vmgenid_add_acpi(dev, state); + if (dev->of_node) + ret =3D vmgenid_add_of(pdev, state); + else + ret =3D vmgenid_add_acpi(dev, state); =20 if (ret < 0) devm_kfree(dev, state); return ret; } =20 +static const struct of_device_id vmgenid_of_ids[] =3D { + { .compatible =3D "microsoft,vmgenid", }, + { }, +}; +MODULE_DEVICE_TABLE(of, vmgenid_of_ids); + static const struct acpi_device_id vmgenid_acpi_ids[] =3D { { "VMGENCTR", 0 }, { "VM_GEN_COUNTER", 0 }, @@ -122,6 +170,7 @@ static struct platform_driver vmgenid_plaform_driver = =3D { .driver =3D { .name =3D "vmgenid", .acpi_match_table =3D vmgenid_acpi_ids, + .of_match_table =3D vmgenid_of_ids, }, }; =20 --=20 2.44.0