Re: [PATCH v11 14/14] selftests/sgx: Add scripts for EPC cgroup testing

Haitao Huang
2024-04-15T03:13:20Z

On Sun, 14 Apr 2024 10:01:03 -0500, Jarkko Sakkinen <jarkko@kernel.org>
wrote:

> On Wed Apr 10, 2024 at 9:25 PM EEST, Haitao Huang wrote:
>> To run selftests for EPC cgroup:
>>
>> sudo ./run_epc_cg_selftests.sh
>>
>> To watch misc cgroup 'current' changes during testing, run this in a
>> separate terminal:
>>
>> ./watch_misc_for_tests.sh current
>>
>> With different cgroups, the script starts one or multiple concurrent SGX
>> selftests (test_sgx), each to run the unclobbered_vdso_oversubscribed
>> test case, which loads an enclave of EPC size equal to the EPC capacity
>> available on the platform. The script checks results against the
>> expectation set for each cgroup and reports success or failure.
>>
>> The script creates 3 different cgroups at the beginning with following
>> expectations:
>>
>> 1) SMALL - intentionally small enough to fail the test loading an
>> enclave of size equal to the capacity.
>> 2) LARGE - large enough to run up to 4 concurrent tests but fail some if
>> more than 4 concurrent tests are run. The script starts 4 expecting at
>> least one test to pass, and then starts 5 expecting at least one test
>> to fail.
>> 3) LARGER - limit is the same as the capacity, large enough to run lots
>> of
>> concurrent tests. The script starts 8 of them and expects all pass.
>> Then it reruns the same test with one process randomly killed and
>> usage checked to be zero after all processes exit.
>>
>> The script also includes a test with low mem_cg limit and LARGE sgx_epc
>> limit to verify that the RAM used for per-cgroup reclamation is charged
>> to a proper mem_cg. For this test, it turns off swapping before start,
>> and turns swapping back on afterwards.
>>
>> Signed-off-by: Haitao Huang <haitao.huang@linux.intel.com>
>> ---
>> V11:
>> - Remove cgroups-tools dependency and make scripts ash compatible.
>> (Jarkko)
>> - Drop support for cgroup v1 and simplify. (Michal, Jarkko)
>> - Add documentation for functions. (Jarkko)
>> - Turn off swapping before memcontrol tests and back on after
>> - Format and style fixes, name for hard coded values
>>
>> V7:
>> - Added memcontrol test.
>>
>> V5:
>> - Added script with automatic results checking, remove the interactive
>> script.
>> - The script can run independent from the series below.
>> ---
>> tools/testing/selftests/sgx/ash_cgexec.sh | 16 +
>> .../selftests/sgx/run_epc_cg_selftests.sh | 275 ++++++++++++++++++
>> .../selftests/sgx/watch_misc_for_tests.sh | 11 +
>> 3 files changed, 302 insertions(+)
>> create mode 100755 tools/testing/selftests/sgx/ash_cgexec.sh
>> create mode 100755 tools/testing/selftests/sgx/run_epc_cg_selftests.sh
>> create mode 100755 tools/testing/selftests/sgx/watch_misc_for_tests.sh
>>
>> diff --git a/tools/testing/selftests/sgx/ash_cgexec.sh
>> b/tools/testing/selftests/sgx/ash_cgexec.sh
>> new file mode 100755
>> index 000000000000..cfa5d2b0e795
>> --- /dev/null
>> +++ b/tools/testing/selftests/sgx/ash_cgexec.sh
>> @@ -0,0 +1,16 @@
>> +#!/usr/bin/env sh
>> +# SPDX-License-Identifier: GPL-2.0
>> +# Copyright(c) 2024 Intel Corporation.
>> +
>> +# Start a program in a given cgroup.
>> +# Supports V2 cgroup paths, relative to /sys/fs/cgroup
>> +if [ "$#" -lt 2 ]; then
>> + echo "Usage: $0 <v2 cgroup path> <command> [args...]"
>> + exit 1
>> +fi
>> +# Move this shell to the cgroup.
>> +echo 0 >/sys/fs/cgroup/$1/cgroup.procs
>> +shift
>> +# Execute the command within the cgroup
>> +exec "$@"
>> +
>> diff --git a/tools/testing/selftests/sgx/run_epc_cg_selftests.sh
>> b/tools/testing/selftests/sgx/run_epc_cg_selftests.sh
>> new file mode 100755
>> index 000000000000..dd56273056fc
>> --- /dev/null
>> +++ b/tools/testing/selftests/sgx/run_epc_cg_selftests.sh
>> @@ -0,0 +1,275 @@
>> +#!/usr/bin/env sh
>> +# SPDX-License-Identifier: GPL-2.0
>> +# Copyright(c) 2023, 2024 Intel Corporation.
>> +
>> +TEST_ROOT_CG=selftest
>> +TEST_CG_SUB1=$TEST_ROOT_CG/test1
>> +TEST_CG_SUB2=$TEST_ROOT_CG/test2
>> +# We will only set limit in test1 and run tests in test3
>> +TEST_CG_SUB3=$TEST_ROOT_CG/test1/test3
>> +TEST_CG_SUB4=$TEST_ROOT_CG/test4
>> +
>> +# Cgroup v2 only
>> +CG_ROOT=/sys/fs/cgroup
>> +mkdir -p $CG_ROOT/$TEST_CG_SUB1
>> +mkdir -p $CG_ROOT/$TEST_CG_SUB2
>> +mkdir -p $CG_ROOT/$TEST_CG_SUB3
>> +mkdir -p $CG_ROOT/$TEST_CG_SUB4
>> +
>> +# Turn on misc and memory controller in non-leaf nodes
>> +echo "+misc" > $CG_ROOT/cgroup.subtree_control && \
>> +echo "+memory" > $CG_ROOT/cgroup.subtree_control && \
>> +echo "+misc" > $CG_ROOT/$TEST_ROOT_CG/cgroup.subtree_control && \
>> +echo "+memory" > $CG_ROOT/$TEST_ROOT_CG/cgroup.subtree_control && \
>> +echo "+misc" > $CG_ROOT/$TEST_CG_SUB1/cgroup.subtree_control
>> +if [ $? -ne 0 ]; then
>> + echo "# Failed setting up cgroups, make sure misc and memory
>> cgroups are enabled."
>> + exit 1
>> +fi
>> +
>> +CAPACITY=$(grep "sgx_epc" "$CG_ROOT/misc.capacity" | awk '{print $2}')
>> +# This is below number of VA pages needed for enclave of capacity
>> size. So
>> +# should fail oversubscribed cases
>> +SMALL=$(( CAPACITY / 512 ))
>> +
>> +# At least load one enclave of capacity size successfully, maybe up to
>> 4.
>> +# But some may fail if we run more than 4 concurrent enclaves of
>> capacity size.
>> +LARGE=$(( SMALL * 4 ))
>> +
>> +# Load lots of enclaves
>> +LARGER=$CAPACITY
>> +echo "# Setting up limits."
>> +echo "sgx_epc $SMALL" > $CG_ROOT/$TEST_CG_SUB1/misc.max && \
>> +echo "sgx_epc $LARGE" > $CG_ROOT/$TEST_CG_SUB2/misc.max && \
>> +echo "sgx_epc $LARGER" > $CG_ROOT/$TEST_CG_SUB4/misc.max
>> +if [ $? -ne 0 ]; then
>> + echo "# Failed setting up misc limits."
>> + exit 1
>> +fi
>> +
>> +clean_up()
>> +{
>> + sleep 2
>> + rmdir $CG_ROOT/$TEST_CG_SUB2
>> + rmdir $CG_ROOT/$TEST_CG_SUB3
>> + rmdir $CG_ROOT/$TEST_CG_SUB4
>> + rmdir $CG_ROOT/$TEST_CG_SUB1
>> + rmdir $CG_ROOT/$TEST_ROOT_CG
>> +}
>> +
>> +timestamp=$(date +%Y%m%d_%H%M%S)
>> +
>> +test_cmd="./test_sgx -t unclobbered_vdso_oversubscribed"
>> +
>> +PROCESS_SUCCESS=1
>> +PROCESS_FAILURE=0
>> +
>> +# Wait for a process and check for expected exit status.
>> +#
>> +# Arguments:
>> +# $1 - the pid of the process to wait and check.
>> +# $2 - 1 if expecting success, 0 for failure.
>> +#
>> +# Return:
>> +# 0 if the exit status of the process matches the expectation.
>> +# 1 otherwise.
>> +wait_check_process_status() {
>> + pid=$1
>> + check_for_success=$2
>> +
>> + wait "$pid"
>> + status=$?
>> +
>> + if [ $check_for_success -eq $PROCESS_SUCCESS ] && [ $status -eq 0
>> ]; then
>> + echo "# Process $pid succeeded."
>> + return 0
>> + elif [ $check_for_success -eq $PROCESS_FAILURE ] && [ $status -ne
>> 0 ]; then
>> + echo "# Process $pid returned failure."
>> + return 0
>> + fi
>> + return 1
>> +}
>> +
>> +# Wait for a set of processes and check for expected exit status
>> +#
>> +# Arguments:
>> +# $1 - 1 if expecting success, 0 for failure.
>> +# remaining args - The pids of the processes
>> +#
>> +# Return:
>> +# 0 if exit status of any process matches the expectation.
>> +# 1 otherwise.
>> +wait_and_detect_for_any() {
>> + check_for_success=$1
>> +
>> + shift
>> + detected=1 # 0 for success detection
>> +
>> + for pid in $@; do
>> + if wait_check_process_status "$pid" "$check_for_success"; then
>> + detected=0
>> + # Wait for other processes to exit
>> + fi
>> + done
>> +
>> + return $detected
>> +}
>> +
>> +echo "# Start unclobbered_vdso_oversubscribed with SMALL limit,
>> expecting failure..."
>> +# Always use leaf node of misc cgroups
>> +# these may fail on OOM
>> +./ash_cgexec.sh $TEST_CG_SUB3 $test_cmd >cgtest_small_$timestamp.log
>> 2>&1
>> +if [ $? -eq 0 ]; then
>> + echo "# Fail on SMALL limit, not expecting any test passes."
>> + clean_up
>> + exit 1
>> +else
>> + echo "# Test failed as expected."
>> +fi
>> +
>> +echo "# PASSED SMALL limit."
>> +
>> +echo "# Start 4 concurrent unclobbered_vdso_oversubscribed tests with
>> LARGE limit,
>> + expecting at least one success...."
>> +
>> +pids=""
>> +for i in 1 2 3 4; do
>> + (
>> + ./ash_cgexec.sh $TEST_CG_SUB2 $test_cmd
>> >cgtest_large_positive_$timestamp.$i.log 2>&1
>> + ) &
>> + pids="$pids $!"
>> +done
>> +
>> +
>> +if wait_and_detect_for_any $PROCESS_SUCCESS "$pids"; then
>> + echo "# PASSED LARGE limit positive testing."
>> +else
>> + echo "# Failed on LARGE limit positive testing, no test passes."
>> + clean_up
>> + exit 1
>> +fi
>> +
>> +echo "# Start 5 concurrent unclobbered_vdso_oversubscribed tests with
>> LARGE limit,
>> + expecting at least one failure...."
>> +pids=""
>> +for i in 1 2 3 4 5; do
>> + (
>> + ./ash_cgexec.sh $TEST_CG_SUB2 $test_cmd
>> >cgtest_large_negative_$timestamp.$i.log 2>&1
>> + ) &
>> + pids="$pids $!"
>> +done
>> +
>> +if wait_and_detect_for_any $PROCESS_FAILURE "$pids"; then
>> + echo "# PASSED LARGE limit negative testing."
>> +else
>> + echo "# Failed on LARGE limit negative testing, no test fails."
>> + clean_up
>> + exit 1
>> +fi
>> +
>> +echo "# Start 8 concurrent unclobbered_vdso_oversubscribed tests with
>> LARGER limit,
>> + expecting no failure...."
>> +pids=""
>> +for i in 1 2 3 4 5 6 7 8; do
>> + (
>> + ./ash_cgexec.sh $TEST_CG_SUB4 $test_cmd
>> >cgtest_larger_$timestamp.$i.log 2>&1
>> + ) &
>> + pids="$pids $!"
>> +done
>> +
>> +if wait_and_detect_for_any $PROCESS_FAILURE "$pids"; then
>> + echo "# Failed on LARGER limit, at least one test fails."
>> + clean_up
>> + exit 1
>> +else
>> + echo "# PASSED LARGER limit tests."
>> +fi
>> +
>> +echo "# Start 8 concurrent unclobbered_vdso_oversubscribed tests with
>> LARGER limit,
>> + randomly kill one, expecting no failure...."
>> +pids=""
>> +for i in 1 2 3 4 5 6 7 8; do
>> + (
>> + ./ash_cgexec.sh $TEST_CG_SUB4 $test_cmd
>> >cgtest_larger_kill_$timestamp.$i.log 2>&1
>> + ) &
>> + pids="$pids $!"
>> +done
>> +random_number=$(awk 'BEGIN{srand();print int(rand()*5)}')
>> +sleep $((random_number + 1))
>> +
>> +# Randomly select a process to kill
>> +# Make sure usage counter not leaked at the end.
>> +RANDOM_INDEX=$(awk 'BEGIN{srand();print int(rand()*8)}')
>> +counter=0
>> +for pid in $pids; do
>> + if [ "$counter" -eq "$RANDOM_INDEX" ]; then
>> + PID_TO_KILL=$pid
>> + break
>> + fi
>> + counter=$((counter + 1))
>> +done
>> +
>> +kill $PID_TO_KILL
>> +echo "# Killed process with PID: $PID_TO_KILL"
>> +
>> +any_failure=0
>> +for pid in $pids; do
>> + wait "$pid"
>> + status=$?
>> + if [ "$pid" != "$PID_TO_KILL" ]; then
>> + if [ $status -ne 0 ]; then
>> + echo "# Process $pid returned failure."
>> + any_failure=1
>> + fi
>> + fi
>> +done
>> +
>> +if [ $any_failure -ne 0 ]; then
>> + echo "# Failed on random killing, at least one test fails."
>> + clean_up
>> + exit 1
>> +fi
>> +echo "# PASSED LARGER limit test with a process randomly killed."
>> +
>> +MEM_LIMIT_TOO_SMALL=$((CAPACITY - 2 * LARGE))
>> +
>> +echo "$MEM_LIMIT_TOO_SMALL" > $CG_ROOT/$TEST_CG_SUB2/memory.max
>> +if [ $? -ne 0 ]; then
>> + echo "# Failed creating memory controller."
>> + clean_up
>> + exit 1
>> +fi
>> +
>> +echo "# Start 4 concurrent unclobbered_vdso_oversubscribed tests with
>> LARGE EPC limit,
>> + and too small RAM limit, expecting all failures...."
>> +# Ensure swapping off so the OOM killer is activated when mem_cgroup
>> limit is hit.
>> +swapoff -a
>> +pids=""
>> +for i in 1 2 3 4; do
>> + (
>> + ./ash_cgexec.sh $TEST_CG_SUB2 $test_cmd
>> >cgtest_large_oom_$timestamp.$i.log 2>&1
>> + ) &
>> + pids="$pids $!"
>> +done
>> +
>> +if wait_and_detect_for_any $PROCESS_SUCCESS "$pids"; then
>> + echo "# Failed on tests with memcontrol, some tests did not fail."
>> + clean_up
>> + swapon -a
>> + exit 1
>> +else
>> + swapon -a
>> + echo "# PASSED LARGE limit tests with memcontrol."
>> +fi
>> +
>> +sleep 2
>> +
>> +USAGE=$(grep '^sgx_epc' "$CG_ROOT/$TEST_ROOT_CG/misc.current" | awk
>> '{print $2}')
>> +if [ "$USAGE" -ne 0 ]; then
>> + echo "# Failed: Final usage is $USAGE, not 0."
>> +else
>> + echo "# PASSED leakage check."
>> + echo "# PASSED ALL cgroup limit tests, cleanup cgroups..."
>> +fi
>> +clean_up
>> +echo "# done."
>> diff --git a/tools/testing/selftests/sgx/watch_misc_for_tests.sh
>> b/tools/testing/selftests/sgx/watch_misc_for_tests.sh
>> new file mode 100755
>> index 000000000000..1c9985726ace
>> --- /dev/null
>> +++ b/tools/testing/selftests/sgx/watch_misc_for_tests.sh
>> @@ -0,0 +1,11 @@
>> +#!/usr/bin/env sh
>> +# SPDX-License-Identifier: GPL-2.0
>> +# Copyright(c) 2023, 2024 Intel Corporation.
>> +
>> +if [ -z "$1" ]; then
>> + echo "No argument supplied, please provide 'max', 'current', or
>> 'events'"
>> + exit 1
>> +fi
>> +
>> +watch -n 1 'find /sys/fs/cgroup -wholename "*/test*/misc.'$1'" -exec \
>> + sh -c '\''echo "$1:"; cat "$1"'\'' _ {} \;'
>
> So this is what happens now:
>
> jarkko@mustatorvisieni:~/linux-tpmdd> make -C
> tools/testing/selftests/sgx run_tests
> make: Entering directory
> '/home/jarkko/linux-tpmdd/tools/testing/selftests/sgx'
> TAP version 13
> 1..1
> # timeout set to 45
> # selftests: sgx: test_sgx
> # TAP version 13
> # 1..16
> # # Starting 16 tests from 1 test cases.
> # # RUN enclave.unclobbered_vdso ...
> # # OK enclave.unclobbered_vdso
> # ok 1 enclave.unclobbered_vdso
> # # RUN enclave.unclobbered_vdso_oversubscribed ...
> # # OK enclave.unclobbered_vdso_oversubscribed
> # ok 2 enclave.unclobbered_vdso_oversubscribed
> # # RUN enclave.unclobbered_vdso_oversubscribed_remove ...
> # # main.c:402:unclobbered_vdso_oversubscribed_remove:Creating an
> enclave with 98566144 bytes heap may take a while ...
> # # main.c:457:unclobbered_vdso_oversubscribed_remove:Changing type of
> 98566144 bytes to trimmed may take a while ...
> # # main.c:473:unclobbered_vdso_oversubscribed_remove:Entering enclave
> to run EACCEPT for each page of 98566144 bytes may take a while ...
> # # main.c:494:unclobbered_vdso_oversubscribed_remove:Removing 98566144
> bytes from enclave may take a while ...
> # # OK enclave.unclobbered_vdso_oversubscribed_remove
> # ok 3 enclave.unclobbered_vdso_oversubscribed_remove
> # # RUN enclave.clobbered_vdso ...
> # # OK enclave.clobbered_vdso
> # ok 4 enclave.clobbered_vdso
> # # RUN enclave.clobbered_vdso_and_user_function ...
> # # OK enclave.clobbered_vdso_and_user_function
> # ok 5 enclave.clobbered_vdso_and_user_function
> # # RUN enclave.tcs_entry ...
> # # OK enclave.tcs_entry
> # ok 6 enclave.tcs_entry
> # # RUN enclave.pte_permissions ...
> # # OK enclave.pte_permissions
> # ok 7 enclave.pte_permissions
> # # RUN enclave.tcs_permissions ...
> # # OK enclave.tcs_permissions
> # ok 8 enclave.tcs_permissions
> # # RUN enclave.epcm_permissions ...
> # # OK enclave.epcm_permissions
> # ok 9 enclave.epcm_permissions
> # # RUN enclave.augment ...
> # # OK enclave.augment
> # ok 10 enclave.augment
> # # RUN enclave.augment_via_eaccept ...
> # # OK enclave.augment_via_eaccept
> # ok 11 enclave.augment_via_eaccept
> # # RUN enclave.tcs_create ...
> # # OK enclave.tcs_create
> # ok 12 enclave.tcs_create
> # # RUN enclave.remove_added_page_no_eaccept ...
> # # OK enclave.remove_added_page_no_eaccept
> # ok 13 enclave.remove_added_page_no_eaccept
> # # RUN enclave.remove_added_page_invalid_access ...
> # # OK enclave.remove_added_page_invalid_access
> # ok 14 enclave.remove_added_page_invalid_access
> # # RUN
> enclave.remove_added_page_invalid_access_after_eaccept ...
> # # OK enclave.remove_added_page_invalid_access_after_eaccept
> # ok 15 enclave.remove_added_page_invalid_access_after_eaccept
> # # RUN enclave.remove_untouched_page ...
> # # OK enclave.remove_untouched_page
> # ok 16 enclave.remove_untouched_page
> # # PASSED: 16 / 16 tests passed.
> # # Totals: pass:16 fail:0 xfail:0 xpass:0 skip:0 error:0
> ok 1 selftests: sgx: test_sgx
>
> Also cgroups tests are expected to run when invoking "run_tests".
>
I can add the SGX cgroup tests to the "run_tests" target. But it will need
more than the 45secs given by the default timeout especially on platforms
with larger EPC. You will need run with --override-timeout
(current SGX selftests also timeout for default 45 sec on a server with 4G
EPC).

> I also wonder do we really want this:
>
> diff --git a/config/x86_64/default b/config/x86_64/default
> index 246b1f3df46..6c3d20af7b4 100644
> --- a/config/x86_64/default
> +++ b/config/x86_64/default
> @@ -502,6 +502,7 @@ CONFIG_X86_INTEL_TSX_MODE_OFF=y
> # CONFIG_X86_INTEL_TSX_MODE_ON is not set
> # CONFIG_X86_INTEL_TSX_MODE_AUTO is not set
> CONFIG_X86_SGX=y
> +CONFIG_CGROUP_SGX_EPC=y
> # CONFIG_X86_USER_SHADOW_STACK is not set
> CONFIG_EFI=y
> CONFIG_EFI_STUB=y
>
> It is a small change but affects all of downstream, not just OpenSUSE.
>
> I hard time projecting a situation where you wanted SGX but without
> cgroups support so perhaps it would be a better idea to enable cgroups
> unconditionally when SGX and cgroups are part of the kernel config?
>
> Then downstream can just pick the patches and call it a day...
>
> BR, Jarkko
>

I don't have issue to remove this config and conditionally compile in SGX
cgroup implementation when MISC is configured.

Thanks
Haitao