On 3/3/23 7:06 PM, Elliot Berman wrote:
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@xxxxxxxxxxx>
Looks good.
Reviewed-by: Alex Elder <elder@xxxxxxxxxx>
---
drivers/virt/Makefile | 1 +
drivers/virt/gunyah/Makefile | 3 ++
drivers/virt/gunyah/gunyah.c | 57 ++++++++++++++++++++++++++++++++++++
3 files changed, 61 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 e9aa6fc96fab..a5817e2d7d71 100644
--- a/drivers/virt/Makefile
+++ b/drivers/virt/Makefile
@@ -12,3 +12,4 @@ obj-$(CONFIG_ACRN_HSM) += acrn/
obj-$(CONFIG_EFI_SECRET) += coco/efi_secret/
obj-$(CONFIG_SEV_GUEST) += coco/sev-guest/
obj-$(CONFIG_INTEL_TDX_GUEST) += coco/tdx-guest/
+obj-y += gunyah/
diff --git a/drivers/virt/gunyah/Makefile b/drivers/virt/gunyah/Makefile
new file mode 100644
index 000000000000..34f32110faf9
--- /dev/null
+++ b/drivers/virt/gunyah/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0
+
+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..4b7e6f3edaff
--- /dev/null
+++ b/drivers/virt/gunyah/gunyah.c
@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2022-2023 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>
+
+static struct gh_hypercall_hyp_identify_resp gh_api;
+
+u16 gh_api_version(void)
+{
+ return FIELD_GET(GH_API_INFO_API_VERSION_MASK, gh_api.api_info);
+}
+EXPORT_SYMBOL_GPL(gh_api_version);
+
+bool gh_api_has_feature(enum gh_api_feature feature)
+{
+ switch (feature) {
+ case GH_FEATURE_DOORBELL:
+ case GH_FEATURE_MSGQUEUE:
+ case GH_FEATURE_VCPU:
+ case GH_FEATURE_MEMEXTENT:
+ return !!(gh_api.flags[0] & BIT_ULL(feature));
+ default:
+ return false;
+ }
+}
+EXPORT_SYMBOL_GPL(gh_api_has_feature);
+
+static int __init gh_init(void)
+{
+ if (!arch_is_gh_guest())
+ return -ENODEV;
+
+ gh_hypercall_hyp_identify(&gh_api);
+
+ pr_info("Running under Gunyah hypervisor %llx/v%u\n",
+ FIELD_GET(GH_API_INFO_VARIANT_MASK, gh_api.api_info),
+ gh_api_version());
+
+ /* We might move this out to individual drivers if there's ever an API version bump */
+ if (gh_api_version() != GH_API_V1) {
+ pr_info("Unsupported Gunyah version: %u\n", gh_api_version());
+ return -ENODEV;
+ }
+
+ return 0;
+}
+arch_initcall(gh_init);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Gunyah Hypervisor Driver");
