From: Babis Chalios <bchalios@amazon.es>
To: <tytso@mit.edu>, <Jason@zx2c4.com>, <olivia@selenic.com>,
<herbert@gondor.apana.org.au>, <robh@kernel.org>,
<krzk+dt@kernel.org>, <conor+dt@kernel.org>,
<linux-crypto@vger.kernel.org>, <devicetree@vger.kernel.org>,
<linux-kernel@vger.kernel.org>
Cc: <sudanl@amazon.com>, <bchalios@amazon.es>, <graf@amazon.de>,
<xmarcalx@amazon.co.uk>, <dwmw@amazon.co.uk>
Subject: [PATCH v5 5/5] virt: vmgenid: add support for devicetree bindings
Date: Wed, 17 Apr 2024 10:12:12 +0200 [thread overview]
Message-ID: <20240417081212.99657-6-bchalios@amazon.es> (raw)
In-Reply-To: <20240417081212.99657-1-bchalios@amazon.es>
From: Sudan Landge <sudanl@amazon.com>
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
Signed-off-by: Sudan Landge <sudanl@amazon.com>
---
drivers/virt/vmgenid.c | 53 ++++++++++++++++++++++++++++++++++++++++--
1 file changed, 51 insertions(+), 2 deletions(-)
diff --git a/drivers/virt/vmgenid.c b/drivers/virt/vmgenid.c
index 3d93e3fb94c4..9a3c12e5dd6e 100644
--- a/drivers/virt/vmgenid.c
+++ b/drivers/virt/vmgenid.c
@@ -2,12 +2,13 @@
/*
* Copyright (C) 2022 Jason A. Donenfeld <Jason@zx2c4.com>. 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 <linux/acpi.h>
+#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
@@ -20,6 +21,7 @@ enum { VMGENID_SIZE = 16 };
struct vmgenid_state {
u8 *next_id;
u8 this_id[VMGENID_SIZE];
+ int irq;
};
static void vmgenid_notify(struct device *device)
@@ -43,6 +45,14 @@ vmgenid_acpi_handler(acpi_handle __always_unused handle,
vmgenid_notify(dev);
}
+static irqreturn_t
+vmgenid_of_irq_handler(int __always_unused irq, void *dev)
+{
+ vmgenid_notify(dev);
+
+ return IRQ_HANDLED;
+}
+
static int __maybe_unused
setup_vmgenid_state(struct vmgenid_state *state, u8 *next_id)
{
@@ -106,6 +116,35 @@ static int vmgenid_add_acpi(struct device __maybe_unused *dev,
#endif
}
+static int vmgenid_add_of(struct platform_device *pdev,
+ struct vmgenid_state *state)
+{
+ u8 *virt_addr;
+ int ret = 0;
+
+ virt_addr = (u8 *)devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
+ if (IS_ERR(virt_addr))
+ return PTR_ERR(virt_addr);
+
+ ret = setup_vmgenid_state(state, virt_addr);
+ if (ret)
+ return ret;
+
+ ret = platform_get_irq(pdev, 0);
+ if (ret < 0)
+ return ret;
+
+ state->irq = ret;
+ pdev->dev.driver_data = state;
+
+ ret = devm_request_irq(&pdev->dev, state->irq, vmgenid_of_irq_handler,
+ IRQF_SHARED, "vmgenid", &pdev->dev);
+ if (ret)
+ pdev->dev.driver_data = NULL;
+
+ return ret;
+}
+
static int vmgenid_add(struct platform_device *pdev)
{
struct vmgenid_state *state;
@@ -116,7 +155,10 @@ 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);
@@ -124,6 +166,12 @@ static int vmgenid_add(struct platform_device *pdev)
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 },
@@ -136,6 +184,7 @@ static struct platform_driver vmgenid_plaform_driver = {
.driver = {
.name = "vmgenid",
.acpi_match_table = vmgenid_acpi_ids,
+ .of_match_table = vmgenid_of_ids,
},
};
--
2.40.1
next prev parent reply other threads:[~2024-04-17 8:14 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-17 8:12 [PATCH v5 0/5] virt: vmgenid: Add devicetree bindings support Babis Chalios
2024-04-17 8:12 ` [PATCH v5 1/5] virt: vmgenid: rearrange code to make review easier Babis Chalios
2024-04-17 8:35 ` Alexander Graf
2024-04-17 9:05 ` Babis Chalios
2024-04-17 9:12 ` Alexander Graf
2024-04-17 12:42 ` Jason A. Donenfeld
2024-04-17 13:19 ` Krzysztof Kozlowski
2024-04-17 8:12 ` [PATCH v5 2/5] virt: vmgenid: change implementation to use a platform driver Babis Chalios
2024-04-17 8:12 ` [PATCH v5 3/5] virt: vmgenid: enable driver regardless of ACPI config Babis Chalios
2024-04-17 8:12 ` [PATCH v5 4/5] dt-bindings: rng: Add vmgenid support Babis Chalios
2024-04-17 8:41 ` Alexander Graf
2024-04-17 13:16 ` Krzysztof Kozlowski
2024-04-17 13:16 ` Krzysztof Kozlowski
2024-04-17 8:12 ` Babis Chalios [this message]
2024-04-17 13:17 ` [PATCH v5 5/5] virt: vmgenid: add support for devicetree bindings Krzysztof Kozlowski
2024-04-17 8:44 ` [PATCH v5 0/5] virt: vmgenid: Add devicetree bindings support Alexander Graf
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20240417081212.99657-6-bchalios@amazon.es \
--to=bchalios@amazon.es \
--cc=Jason@zx2c4.com \
--cc=conor+dt@kernel.org \
--cc=devicetree@vger.kernel.org \
--cc=dwmw@amazon.co.uk \
--cc=graf@amazon.de \
--cc=herbert@gondor.apana.org.au \
--cc=krzk+dt@kernel.org \
--cc=linux-crypto@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=olivia@selenic.com \
--cc=robh@kernel.org \
--cc=sudanl@amazon.com \
--cc=tytso@mit.edu \
--cc=xmarcalx@amazon.co.uk \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.