The Virtual Trust Level platforms rely on DeviceTree, and the arm64/hyperv code supports ACPI only. Update the logic to support DeviceTree on boot as well as ACPI. Signed-off-by: Roman Kisel <romank@xxxxxxxxxxxxxxxxxxx> --- arch/arm64/hyperv/mshyperv.c | 34 +++++++++++++++++++++++++++++----- 1 file changed, 29 insertions(+), 5 deletions(-) diff --git a/arch/arm64/hyperv/mshyperv.c b/arch/arm64/hyperv/mshyperv.c index b1a4de4eee29..208a3bcb9686 100644 --- a/arch/arm64/hyperv/mshyperv.c +++ b/arch/arm64/hyperv/mshyperv.c @@ -15,6 +15,9 @@ #include <linux/errno.h> #include <linux/version.h> #include <linux/cpuhotplug.h> +#include <linux/libfdt.h> +#include <linux/of.h> +#include <linux/of_fdt.h> #include <asm/mshyperv.h> static bool hyperv_initialized; @@ -27,6 +30,29 @@ int hv_get_hypervisor_version(union hv_hypervisor_version_info *info) return 0; } +static bool hyperv_detect_fdt(void) +{ +#ifdef CONFIG_OF + const unsigned long hyp_node = of_get_flat_dt_subnode_by_name( + of_get_flat_dt_root(), "hypervisor"); + + return (hyp_node != -FDT_ERR_NOTFOUND) && + of_flat_dt_is_compatible(hyp_node, "microsoft,hyperv"); +#else + return false; +#endif +} + +static bool hyperv_detect_acpi(void) +{ +#ifdef CONFIG_ACPI + return !acpi_disabled && + !strncmp((char *)&acpi_gbl_FADT.hypervisor_id, "MsHyperV", 8); +#else + return false; +#endif +} + static int __init hyperv_init(void) { struct hv_get_vp_registers_output result; @@ -35,13 +61,11 @@ static int __init hyperv_init(void) /* * Allow for a kernel built with CONFIG_HYPERV to be running in - * a non-Hyper-V environment, including on DT instead of ACPI. + * a non-Hyper-V environment. + * * In such cases, do nothing and return success. */ - if (acpi_disabled) - return 0; - - if (strncmp((char *)&acpi_gbl_FADT.hypervisor_id, "MsHyperV", 8)) + if (!hyperv_detect_fdt() && !hyperv_detect_acpi()) return 0; /* Setup the guest ID */ -- 2.45.0