Move ring0 package.

This allows the package to serve as a general purpose ring0 support package, as
opposed to being bound to specific sentry platforms.

Updates #5039

PiperOrigin-RevId: 355220044

1 files changed, 88 insertions, 0 deletions

diff --git a/pkg/ring0/pagetables/BUILD b/pkg/ring0/pagetables/BUILD
new file mode 100644
index 000000000..65a978cbb
--- /dev/null
+++ b/pkg/ring0/pagetables/BUILD
@@ -0,0 +1,88 @@
+load("//tools:defs.bzl", "go_library", "go_test")
+load("//tools/go_generics:defs.bzl", "go_template", "go_template_instance")
+
+package(licenses = ["notice"])
+
+[
+    # These files are tagged with relevant build architectures. We can always
+    # build all the input files, which will be included only in the relevant
+    # architecture builds.
+    go_template(
+        name = "generic_walker_%s" % arch,
+        srcs = [
+            "walker_generic.go",
+            "walker_%s.go" % arch,
+        ],
+        opt_types = [
+            "Visitor",
+        ],
+        visibility = [":__pkg__"],
+    )
+    for arch in ("amd64", "arm64")
+]
+
+[
+    # See above.
+    go_template_instance(
+        name = "walker_%s_%s" % (op, arch),
+        out = "walker_%s_%s.go" % (op, arch),
+        package = "pagetables",
+        prefix = op,
+        template = ":generic_walker_%s" % arch,
+        types = {
+            "Visitor": "%sVisitor" % op,
+        },
+    )
+    for op in ("map", "unmap", "lookup", "empty", "check")
+    for arch in ("amd64", "arm64")
+]
+
+go_library(
+    name = "pagetables",
+    srcs = [
+        "allocator.go",
+        "allocator_unsafe.go",
+        "pagetables.go",
+        "pagetables_aarch64.go",
+        "pagetables_amd64.go",
+        "pagetables_arm64.go",
+        "pagetables_x86.go",
+        "pcids.go",
+        "pcids_aarch64.go",
+        "pcids_aarch64.s",
+        "pcids_x86.go",
+        "walker_amd64.go",
+        "walker_arm64.go",
+        "walker_generic.go",
+        ":walker_empty_amd64",
+        ":walker_empty_arm64",
+        ":walker_lookup_amd64",
+        ":walker_lookup_arm64",
+        ":walker_map_amd64",
+        ":walker_map_arm64",
+        ":walker_unmap_amd64",
+        ":walker_unmap_arm64",
+    ],
+    visibility = [
+        "//pkg/ring0:__subpackages__",
+        "//pkg/sentry/platform/kvm:__subpackages__",
+    ],
+    deps = [
+        "//pkg/sync",
+        "//pkg/usermem",
+    ],
+)
+
+go_test(
+    name = "pagetables_test",
+    size = "small",
+    srcs = [
+        "pagetables_amd64_test.go",
+        "pagetables_arm64_test.go",
+        "pagetables_test.go",
+        ":walker_check_amd64",
+        ":walker_check_arm64",
+    ],
+    library = ":pagetables",
+    deps = ["//pkg/usermem"],
+)