[PATCH v7 06/20] virt: gunyah: Identify hypervisor version

Elliot Berman
2022-11-21T14:03:47Z

Export the version of Gunyah which is reported via the hyp_identify
hypercall. Increments of the major API version indicate possibly
backwards incompatible changes.

Export the hypervisor identity so that Gunyah drivers can act according
to the major API version.

Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>
---
drivers/virt/Makefile | 1 +
drivers/virt/gunyah/Makefile | 1 +
drivers/virt/gunyah/gunyah.c | 46 ++++++++++++++++++++++++++++++++++++
include/linux/gunyah.h | 6 +++++
4 files changed, 54 insertions(+)
create mode 100644 drivers/virt/gunyah/Makefile
create mode 100644 drivers/virt/gunyah/gunyah.c

diff --git a/drivers/virt/Makefile b/drivers/virt/Makefile
index 093674e05c40..92b7e5311548 100644
--- a/drivers/virt/Makefile
+++ b/drivers/virt/Makefile
@@ -11,3 +11,4 @@ obj-$(CONFIG_NITRO_ENCLAVES) += nitro_enclaves/
obj-$(CONFIG_ACRN_HSM) += acrn/
obj-$(CONFIG_EFI_SECRET) += coco/efi_secret/
obj-$(CONFIG_SEV_GUEST) += coco/sev-guest/
+obj-y += gunyah/
diff --git a/drivers/virt/gunyah/Makefile b/drivers/virt/gunyah/Makefile
new file mode 100644
index 000000000000..2ac4ee64b89d
--- /dev/null
+++ b/drivers/virt/gunyah/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_GUNYAH) += gunyah.o
diff --git a/drivers/virt/gunyah/gunyah.c b/drivers/virt/gunyah/gunyah.c
new file mode 100644
index 000000000000..c34c9046fc08
--- /dev/null
+++ b/drivers/virt/gunyah/gunyah.c
@@ -0,0 +1,46 @@
+// 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/gunyah.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/printk.h>
+
+struct gh_hypercall_hyp_identify_resp gunyah_api;
+EXPORT_SYMBOL_GPL(gunyah_api);
+
+static const uint32_t gunyah_known_uuids[][4] = {
+ {0x19bd54bd, 0x0b37571b, 0x946f609b, 0x54539de6}, /* QC_HYP (Qualcomm's build) */
+ {0x673d5f14, 0x9265ce36, 0xa4535fdb, 0xc1d58fcd}, /* GUNYAH (open source build) */
+};
+
+static int __init gunyah_init(void)
+{
+ u32 uid[4];
+ int i;
+
+ gh_hypercall_get_uid(uid);
+
+ for (i = 0; i < ARRAY_SIZE(gunyah_known_uuids); i++)
+ if (!memcmp(uid, gunyah_known_uuids[i], sizeof(uid)))
+ break;
+
+ if (i == ARRAY_SIZE(gunyah_known_uuids))
+ return -ENODEV;
+
+ gh_hypercall_hyp_identify(&gunyah_api);
+
+ pr_info("Running under Gunyah hypervisor %llx/v%u\n",
+ FIELD_GET(GH_API_INFO_VARIANT_MASK, gunyah_api.api_info),
+ gh_api_version());
+
+ return 0;
+}
+arch_initcall(gunyah_init);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Gunyah Hypervisor Driver");
diff --git a/include/linux/gunyah.h b/include/linux/gunyah.h
index 2765d2b40198..166156f69df9 100644
--- a/include/linux/gunyah.h
+++ b/include/linux/gunyah.h
@@ -92,6 +92,12 @@ struct gh_hypercall_hyp_identify_resp {
u64 api_info;
u64 flags[3];
};
+extern struct gh_hypercall_hyp_identify_resp gunyah_api;
+
+static inline u16 gh_api_version(void)
+{
+ return FIELD_GET(GH_API_INFO_API_VERSION_MASK, gunyah_api.api_info);
+}

void gh_hypercall_get_uid(u32 uid[4]);
void gh_hypercall_hyp_identify(struct gh_hypercall_hyp_identify_resp *hyp_identity);
--
2.25.1