diff --git a/.github/workflows/build-viztracer.yml b/.github/workflows/build-viztracer.yml
new file mode 100644
index 000000000..afc325095
--- /dev/null
+++ b/.github/workflows/build-viztracer.yml
@@ -0,0 +1,96 @@
+# SPDX-FileCopyrightText: 2026 The RISE Project
+# SPDX-License-Identifier: MIT
+---
+# Based on upstream's CI:
+#   https://github.com/gaogaotiantian/viztracer/blob/1.1.1/.github/workflows/wheels.yml
+name: Build viztracer wheels (riscv64)
+
+on:
+  workflow_dispatch:
+    inputs:
+      version:
+        description: 'viztracer version to build (git tag, e.g. 1.1.1)'
+        required: true
+        default: '1.1.1'
+  pull_request:
+    paths:
+      - '.github/workflows/build-viztracer.yml'
+      - 'patches/viztracer/**'
+
+concurrency:
+  group: ${{ github.workflow }}-${{ inputs.version || '1.1.1' }}-${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
+permissions:
+  contents: read  # to fetch code (actions/checkout)
+
+env:
+  VIZTRACER_VERSION: ${{ inputs.version || '1.1.1' }}
+  MANYLINUX_RISCV64_IMAGE: quay.io/pypa/manylinux_2_39_riscv64
+
+jobs:
+  setup:
+    uses: $/.github/workflows/_setup.yml
+
+  build_wheels:
+    needs: [setup]
+    name: Build viztracer ${{ inputs.version || '1.1.1' }} ${{ matrix.python }}-manylinux_riscv64
+    runs-on: ubuntu-24.04-riscv
+    timeout-minutes: 60
+    strategy:
+      fail-fast: false
+      matrix:
+        python: ["cp312", "cp313", "cp314", "cp314t"]
+
+    steps:
+      - name: Checkout viztracer ${{ env.VIZTRACER_VERSION }}
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1  # v7.0.1
+        with:
+          repository: gaogaotiantian/viztracer
+          ref: ${{ env.VIZTRACER_VERSION }}
+          persist-credentials: false
+
+      - name: Checkout python-wheels
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1  # v7.0.1
+        with:
+          path: python-wheels
+          persist-credentials: false
+
+      # Two tests hang forever on riscv64 and four fail (see the patches): self-tracing
+      # overhead, Perfetto's trace_processor_shell having no riscv64 prebuilt, and no
+      # riscv64 build of the cross-process attach .so.
+      - name: Patch viztracer source
+        run: |
+          git apply python-wheels/patches/viztracer/${{ env.VIZTRACER_VERSION }}/00*.patch
+
+      - name: Build and test wheel
+        uses: pypa/cibuildwheel@1828c10ab37f080699c7b81cea34097c684a7074  # v4.2.0
+        with:
+          output-dir: wheelhouse/
+          only: ${{ matrix.python }}-manylinux_riscv64
+        env:
+          CIBW_MANYLINUX_RISCV64_IMAGE: ${{ env.MANYLINUX_RISCV64_IMAGE }}
+          # TestLoky (tests/test_multiprocess.py) imports loky unconditionally; every
+          # other optional dep upstream's suite touches (torch, jaxlib, ipywidgets)
+          # is self-skipping on ImportError or platform.
+          CIBW_TEST_REQUIRES: loky>=3.0.0,<3.5.0
+          # cibuildwheel runs the tests in an empty directory, so stage upstream's suite
+          # there; test_combine also reaches outside tests/ for its example data files.
+          CIBW_TEST_SOURCES: tests example/json
+          CIBW_TEST_COMMAND: python -m unittest -v
+
+      - uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a  # v7.0.1
+        with:
+          name: viztracer-${{ env.VIZTRACER_VERSION }}-${{ matrix.python }}-manylinux_riscv64
+          path: wheelhouse/*.whl
+          if-no-files-found: error
+
+  publish:
+    name: Publish viztracer ${{ inputs.version || '1.1.1' }}
+    needs: [setup, build_wheels]
+    permissions:
+      contents: write
+      pull-requests: write
+    uses: $/.github/workflows/_publish-wheel.yml
+    with:
+      artifact-pattern: viztracer-${{ inputs.version || '1.1.1' }}-*-manylinux_riscv64
diff --git a/patches/viztracer/1.1.1/0001-tests-skip-test_trace_self-which-hangs-indefinitely.patch b/patches/viztracer/1.1.1/0001-tests-skip-test_trace_self-which-hangs-indefinitely.patch
new file mode 100644
index 000000000..97c04f785
--- /dev/null
+++ b/patches/viztracer/1.1.1/0001-tests-skip-test_trace_self-which-hangs-indefinitely.patch
@@ -0,0 +1,49 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Ludovic Henry <git@ludovic.dev>
+Date: Sun, 6 Sep 2026 00:00:00 +0000
+Subject: [PATCH] tests: skip test_trace_self, which hangs indefinitely on
+ riscv64
+
+Upstream-Status: Inappropriate [riscv64-only hang, never exercised by upstream's own x86/aarch64 CI hardware]
+
+test_trace_self runs `viztracer --trace_self vizviewer --server_only
+<json>` and waits for "Ctrl+C" to appear on the child's stdout before
+sending SIGTERM (tests/cmdline_tmpl.py's `template()`, string-`wait`
+branch): a plain `while True: line = p.stdout.readline()` loop with no
+timeout at all.
+
+On riscv64 this readline loop never returns: this exact test hung
+identically across all four interpreters (cp312/cp313/cp314/cp314t) until
+GitHub's own 60-minute job timeout killed it, producing zero output after
+"test_trace_self start".
+
+A likely contributing mechanism: get_system_ts()/get_system_ns() in
+src/viztracer/modules/quicktime.h use __rdtsc() on x86 (a single
+non-syscall instruction) but fall back to clock_gettime(CLOCK_MONOTONIC)
+everywhere else, including riscv64, and --trace_self hooks every
+Python-level call. A bounded self-trace smoke test (`viztracer --trace_self
+-c "print(1)"`) still completes in ~1s on this runner, so self-tracing
+alone is not universally catastrophic here -- something specific to
+self-tracing `vizviewer --server_only`'s heavier import graph (argparse,
+socketserver, http.server, ...) and/or its long-running server loop is
+what never reaches the "Press Ctrl+C to quit" print. Regardless of the
+exact mechanism, the test's own wait has no timeout, so any slowdown here
+becomes a permanent hang instead of a failure.
+
+Signed-off-by: Ludovic Henry <git@ludovic.dev>
+---
+ tests/test_cmdline.py | 1 +
+ 1 file changed, 1 insertion(+)
+
+diff --git a/tests/test_cmdline.py b/tests/test_cmdline.py
+index c37d4a2..98efd4d 100644
+--- a/tests/test_cmdline.py
++++ b/tests/test_cmdline.py
+@@ -435,6 +435,7 @@ class TestCommandLineBasic(CmdlineTmpl):
+         self.template([sys.executable, "-m", "viztracer", "--tracer_entries", "1000", "cmdline_test.py"])
+         self.template([sys.executable, "-m", "viztracer", "--tracer_entries", "50", "cmdline_test.py"])
+
++    @skipIf(True, "riscv64: hangs forever, see build-viztracer.yml")
+     def test_trace_self(self):
+         def check_func(data):
+             self.assertGreater(len(data["traceEvents"]), 1000)
diff --git a/patches/viztracer/1.1.1/0002-tests-skip-test_use_external_processor-perfetto-has.patch b/patches/viztracer/1.1.1/0002-tests-skip-test_use_external_processor-perfetto-has.patch
new file mode 100644
index 000000000..22e2e13ce
--- /dev/null
+++ b/patches/viztracer/1.1.1/0002-tests-skip-test_use_external_processor-perfetto-has.patch
@@ -0,0 +1,46 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Ludovic Henry <git@ludovic.dev>
+Date: Sun, 6 Sep 2026 00:00:00 +0000
+Subject: [PATCH] tests: skip test_use_external_processor, which hangs
+ forever on riscv64
+
+Upstream-Status: Inappropriate [riscv64 has no Perfetto trace_processor_shell prebuilt; upstream never exercises this combination]
+
+--use_external_processor shells out to src/viztracer/web_dist/trace_processor,
+Perfetto's own prebuilt-binary launcher. Its TRACE_PROCESSOR_SHELL_MANIFEST
+lists prebuilts only for x86_64 and aarch64 machines; on riscv64 no entry
+matches and it raises "No prebuilts available for linux-riscv64" and exits
+immediately.
+
+viztracer's own ExternalProcessorProcess._wait_start() does not handle that:
+
+    while True:
+        line = self._process.stderr.readline().decode("utf-8")
+        if "This server can be used" in line:
+            break
+
+Once the child has exited, readline() on its now-closed stderr pipe returns
+"" forever instead of blocking, so this becomes a tight busy-loop that spins
+until the CI job's own timeout kills it rather than raising or returning.
+This is a real bug in viztracer (any crashed/fast-exiting trace_processor
+child triggers it, not just a missing riscv64 prebuilt), but the practical
+blocker for us is Perfetto shipping no riscv64 binary at all, which is
+outside what a build/test patch here can fix.
+
+Signed-off-by: Ludovic Henry <git@ludovic.dev>
+---
+ tests/test_viewer.py | 1 +
+ 1 file changed, 1 insertion(+)
+
+diff --git a/tests/test_viewer.py b/tests/test_viewer.py
+index 0000000..0000000 100644
+--- a/tests/test_viewer.py
++++ b/tests/test_viewer.py
+@@ -225,6 +225,7 @@ class TestViewer(CmdlineTmpl):
+             os.remove(f.name)
+
+     @unittest.skipIf(sys.platform == "win32", "Can't send Ctrl+C reliably on Windows")
++    @unittest.skip("riscv64: hangs forever, see build-viztracer.yml")
+     def test_use_external_processor(self):
+         json_script = '{"file_info": {}, "traceEvents": []}'
+         try:
diff --git a/patches/viztracer/1.1.1/0003-tests-skip-attach-tests-riscv64-has-no-attach-so.patch b/patches/viztracer/1.1.1/0003-tests-skip-attach-tests-riscv64-has-no-attach-so.patch
new file mode 100644
index 000000000..acf5cca0a
--- /dev/null
+++ b/patches/viztracer/1.1.1/0003-tests-skip-attach-tests-riscv64-has-no-attach-so.patch
@@ -0,0 +1,73 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Ludovic Henry <git@ludovic.dev>
+Date: Sun, 6 Sep 2026 00:00:00 +0000
+Subject: [PATCH] tests: skip attach tests riscv64 has no attach .so for
+
+Upstream-Status: Inappropriate [riscv64 has no prebuilt attach_riscv64.so; there is no source to build one from]
+
+viztracer ships prebuilt cross-process "attach to a running interpreter"
+shared libraries under src/viztracer/attach_process/ (attach_linux_amd64.so,
+attach_linux_x86.so, attach_x86_64.dylib, ...) vendored from a third-party
+project (see attach_process/LICENSE); there is no C/C++ source for them in
+this repository and no build step compiles them - setup.py's package_data
+only lists whichever prebuilt file matches platform.machine(). There is no
+riscv64 entry at all, so add_code_to_python_process.py's
+run_python_code_linux() always raises "Could not find .so for attach to
+process." on this architecture. This is a real, upstream, no-source-available
+gap, not something a build/test patch here can fix.
+
+tests/test_remote.py's own `attach_unavailable` skip guard only excludes
+win32 and some macOS/Python combinations, so it never anticipated "Linux
+but no attach binary for this CPU architecture" and these tests run and
+fail on riscv64:
+
+  FAIL: test_basic (tests.test_remote.TestAttachSanity.test_basic)
+  FAIL: test_attach (tests.test_remote.TestRemote.test_attach)
+  FAIL: test_attach_installed (tests.test_remote.TestRemote.test_attach_installed)
+  FAIL: test_uninstall (tests.test_remote.TestRemote.test_uninstall)
+
+test_remote.py's own test_install and test_attach_script are unaffected -
+both drive viztracer's in-process attach API (SIGUSR-based install/
+viztracer.attach.start_attach), not the cross-process .so injection path.
+
+Signed-off-by: Ludovic Henry <git@ludovic.dev>
+---
+ tests/test_remote.py | 4 ++++
+ 1 file changed, 4 insertions(+)
+
+diff --git a/tests/test_remote.py b/tests/test_remote.py
+index bbeb27c..f78db47 100644
+--- a/tests/test_remote.py
++++ b/tests/test_remote.py
+@@ -39,6 +39,7 @@ class TestRemote(CmdlineTmpl):
+         self.assertFileExists("remote.json")
+         os.remove("remote.json")
+
++    @unittest.skip("riscv64: no attach_riscv64.so shipped, see build-viztracer.yml")
+     def test_attach_installed(self):
+         file_to_attach = textwrap.dedent("""
+             from viztracer import VizTracer
+@@ -57,6 +58,7 @@ class TestRemote(CmdlineTmpl):
+         self.attach_check(file_to_attach, attach_cmd, output_file)
+         self.attach_check(file_to_attach, attach_installed_cmd, output_file, use_installed=True)
+
++    @unittest.skip("riscv64: no attach_riscv64.so shipped, see build-viztracer.yml")
+     def test_attach(self):
+         file_to_attach = textwrap.dedent("""
+             import time
+@@ -142,6 +144,7 @@ class TestRemote(CmdlineTmpl):
+         p_attach_invalid.wait()
+         self.assertTrue(p_attach_invalid.returncode != 0)
+
++    @unittest.skip("riscv64: no attach_riscv64.so shipped, see build-viztracer.yml")
+     def test_uninstall(self):
+         file_to_attach = textwrap.dedent("""
+             import time
+@@ -228,6 +231,7 @@ class TestRemoteFail(CmdlineTmpl):
+
+ @unittest.skipIf(attach_unavailable, "Does not support this platform")
+ class TestAttachSanity(CmdlineTmpl):
++    @unittest.skip("riscv64: no attach_riscv64.so shipped, see build-viztracer.yml")
+     def test_basic(self):
+         file_to_attach = textwrap.dedent("""
+             import time