Add /sys/hypervisor support when detecting that Linux is running in a
Gunyah environment. Export the version of Gunyah which is reported via
the hyp_identify hypercall.
Signed-off-by: Elliot Berman <quic_eberman@xxxxxxxxxxx>
---
.../ABI/testing/sysfs-hypervisor-gunyah | 23 +++++
MAINTAINERS | 1 +
drivers/virt/Makefile | 1 +
drivers/virt/gunyah/Makefile | 2 +
drivers/virt/gunyah/sysfs.c | 87 +++++++++++++++++++
5 files changed, 114 insertions(+)
create mode 100644 Documentation/ABI/testing/sysfs-hypervisor-gunyah
create mode 100644 drivers/virt/gunyah/Makefile
create mode 100644 drivers/virt/gunyah/sysfs.c
diff --git a/Documentation/ABI/testing/sysfs-hypervisor-gunyah b/Documentation/ABI/testing/sysfs-hypervisor-gunyah
new file mode 100644
index 000000000000..219465783a9e
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-hypervisor-gunyah
@@ -0,0 +1,23 @@
+What: /sys/hypervisor/type
+Date: August 2022
+KernelVersion: 6.0
+Contact: linux-arm-msm@xxxxxxxxxxxxxxx
+Description: If running under Gunyah:
+ Type of hypervisor:
+ "gunyah": Gunyah hypervisor
+
+What: /sys/hypervisor/gunyah/api
+Date: August 2022
+KernelVersion: 6.0
+Contact: linux-arm-msm@xxxxxxxxxxxxxxx
+Description: If running under Gunyah:
+ The Gunyah API version.
+
+What: /sys/hypervisor/gunyah/variant
+Date: August 2022
+KernelVersion: 6.0
+Contact: linux-arm-msm@xxxxxxxxxxxxxxx
+Description: If running under Gunyah:
+ The Gunyah variant (build) version.
+ The open source build of Gunyah will report "81".
+ The Qualcomm build of Gunyah will report "72".
diff --git a/MAINTAINERS b/MAINTAINERS
index f5d5ebb62701..c774bbcdb348 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8739,6 +8739,7 @@ M: Elliot Berman <quic_eberman@xxxxxxxxxxx>
M: Murali Nalajala <quic_mnalajal@xxxxxxxxxxx>
L: linux-arm-msm@xxxxxxxxxxxxxxx
S: Supported
+F: Documentation/ABI/testing/sysfs-hypervisor-gunyah
F: Documentation/devicetree/bindings/firmware/gunyah-hypervisor.yaml
F: Documentation/virt/gunyah/
F: arch/arm64/gunyah/
diff --git a/drivers/virt/Makefile b/drivers/virt/Makefile
index 093674e05c40..5cd759f60122 100644
--- a/drivers/virt/Makefile
+++ b/drivers/virt/Makefile
@@ -9,5 +9,6 @@ obj-y += vboxguest/
obj-$(CONFIG_NITRO_ENCLAVES) += nitro_enclaves/
obj-$(CONFIG_ACRN_HSM) += acrn/
+obj-$(CONFIG_GUNYAH) += gunyah/
obj-$(CONFIG_EFI_SECRET) += coco/efi_secret/
obj-$(CONFIG_SEV_GUEST) += coco/sev-guest/
diff --git a/drivers/virt/gunyah/Makefile b/drivers/virt/gunyah/Makefile
new file mode 100644
index 000000000000..e15f16c17142
--- /dev/null
+++ b/drivers/virt/gunyah/Makefile
@@ -0,0 +1,2 @@
+gunyah-y += sysfs.o
+obj-$(CONFIG_GUNYAH) += gunyah.o
diff --git a/drivers/virt/gunyah/sysfs.c b/drivers/virt/gunyah/sysfs.c
new file mode 100644
index 000000000000..9de700fdbfcb
--- /dev/null
+++ b/drivers/virt/gunyah/sysfs.c
@@ -0,0 +1,87 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#define pr_fmt(fmt) "gunyah: " fmt
+
+#include <linux/kobject.h>
+#include <linux/module.h>
+#include <linux/printk.h>
+#include <linux/init.h>
+#include <asm-generic/gunyah.h>
+
+static struct gh_hypercall_hyp_identify_resp gunyah_api;
+
+static ssize_t type_show(struct kobject *kobj, struct kobj_attribute *attr, char *buffer)
+{
+ return sysfs_emit(buffer, "gunyah\n");
+}
+static struct kobj_attribute type_attr = __ATTR_RO(type);
+
+static ssize_t api_show(struct kobject *kobj, struct kobj_attribute *attr, char *buffer)
+{
+ return sysfs_emit(buffer, "%d\n", (int)GH_API_INFO_API_VERSION(gunyah_api.api_info));
+}
+static struct kobj_attribute api_attr = __ATTR_RO(api);
+
+static ssize_t variant_show(struct kobject *kobj, struct kobj_attribute *attr, char *buffer)
+{
+ return sysfs_emit(buffer, "%d\n", (int)GH_API_INFO_VARIANT(gunyah_api.api_info));
+}
+static struct kobj_attribute variant_attr = __ATTR_RO(variant);
+
+static struct attribute *gunyah_attrs[] = {
+ &api_attr.attr,
+ &variant_attr.attr,
+ NULL
+};
+
+static const struct attribute_group gunyah_group = {
+ .name = "gunyah",
+ .attrs = gunyah_attrs,
+};
+
+static int __init gunyah_init(void)
+{
+ int ret;
+ u32 uid[4];
+
+ gh_hypercall_get_uid(uid);
+
+ if (!(gh_uid_matches(GUNYAH, uid) || gh_uid_matches(QC_HYP, uid)))
+ return 0;
+
+ gh_hypercall_hyp_identify(&gunyah_api);
+
+ if (GH_API_INFO_API_VERSION(gunyah_api.api_info) != 1) {
+ pr_warn("Unrecognized gunyah version: %llu. Currently supported: 1\n",
+ GH_API_INFO_API_VERSION(gunyah_api.api_info));
+ return 0;
+ }
+
+ pr_notice("Running under Gunyah hypervisor %llx/v%lld\n",
+ GH_API_INFO_VARIANT(gunyah_api.api_info),
+ GH_API_INFO_API_VERSION(gunyah_api.api_info));
+
+ ret = sysfs_create_file(hypervisor_kobj, &type_attr.attr);
+ if (ret)
+ return ret;
+
+ ret = sysfs_create_group(hypervisor_kobj, &gunyah_group);
+ if (ret)
+ sysfs_remove_file(hypervisor_kobj, &type_attr.attr);
+
+ return ret;
+}
+module_init(gunyah_init);
+
+static void __exit gunyah_exit(void)
+{
+ sysfs_remove_group(hypervisor_kobj, &gunyah_group);
+ sysfs_remove_file(hypervisor_kobj, &type_attr.attr);
+}
+module_exit(gunyah_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Gunyah Hypervisor Driver");
--
2.25.1
