diff options
| -rw-r--r-- | drivers/virt/Kconfig | 1 | ||||
| -rw-r--r-- | drivers/virt/vmgenid.c | 53 |
2 files changed, 51 insertions, 3 deletions
diff --git a/drivers/virt/Kconfig b/drivers/virt/Kconfig index 40129b6f0eca4..d8c848cf09a6a 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 0522107f9beeb..66135eac3abff 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> @@ -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 @@ out: 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 < 0) + return ret; + + ret = devm_request_irq(&pdev->dev, ret, vmgenid_of_irq_handler, + IRQF_SHARED, "vmgenid", &pdev->dev); + if (ret < 0) + 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 < 0) 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, }, }; |