From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 47838C433EF for ; Mon, 13 Dec 2021 14:20:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238772AbhLMOUt (ORCPT ); Mon, 13 Dec 2021 09:20:49 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:35416 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239067AbhLMOUp (ORCPT ); Mon, 13 Dec 2021 09:20:45 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 5D314B81063; Mon, 13 Dec 2021 14:20:44 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 318B2C34602; Mon, 13 Dec 2021 14:20:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1639405243; bh=5P5l0etMpFAAQ9zSzn1DLe3eLYhIM3xLoFaXmuEMGwQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gXFJ70m9TFsfyO+td7/kSQqebobgqnezyCfSWIjieI2ajuGJkfReTudLDD//HSIJD Cc9DPIqDwPXIWAJjAALLm1oI6C9VQnYaRS5aSYqZhLb17QosdyWFzIq7SlNowsPsSq gYimyVSIwhASGVzOm+91lDpvABT/xG6RvkaOVFBM29a+2mQEdPNAt/nISxL3wboblu 95Yz5G629XfAwbTzoUvs9Ecgv5fiYM7EV2JGkymcMaOwJI76UfkBBe4DJ8sFTagIJa Cz2oA2X+smafEzg2+RfrDEmcFdGNvglBsQAliY6er6ty4+TiDQ5IvaOckcNiSbN8CG FmNhraj1fA+nw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Vitaly Kuznetsov , Sean Christopherson , Paolo Bonzini , Sasha Levin , shuah@kernel.org, kvm@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: [PATCH MANUALSEL 5.4 2/2] KVM: selftests: Make sure kvm_create_max_vcpus test won't hit RLIMIT_NOFILE Date: Mon, 13 Dec 2021 09:20:27 -0500 Message-Id: <20211213142028.352438-2-sashal@kernel.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20211213142028.352438-1-sashal@kernel.org> References: <20211213142028.352438-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Vitaly Kuznetsov [ Upstream commit 908fa88e420f30dde6d80f092795a18ec72ca6d3 ] With the elevated 'KVM_CAP_MAX_VCPUS' value kvm_create_max_vcpus test may hit RLIMIT_NOFILE limits: # ./kvm_create_max_vcpus KVM_CAP_MAX_VCPU_ID: 4096 KVM_CAP_MAX_VCPUS: 1024 Testing creating 1024 vCPUs, with IDs 0...1023. /dev/kvm not available (errno: 24), skipping test Adjust RLIMIT_NOFILE limits to make sure KVM_CAP_MAX_VCPUS fds can be opened. Note, raising hard limit ('rlim_max') requires CAP_SYS_RESOURCE capability which is generally not needed to run kvm selftests (but without raising the limit the test is doomed to fail anyway). Signed-off-by: Vitaly Kuznetsov Message-Id: <20211123135953.667434-1-vkuznets@redhat.com> [Skip the test if the hard limit can be raised. - Paolo] Reviewed-by: Sean Christopherson Tested-by: Sean Christopherson Signed-off-by: Paolo Bonzini Signed-off-by: Sasha Levin --- .../selftests/kvm/kvm_create_max_vcpus.c | 30 +++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/tools/testing/selftests/kvm/kvm_create_max_vcpus.c b/tools/testing/selftests/kvm/kvm_create_max_vcpus.c index 231d79e57774e..cfe75536d8a55 100644 --- a/tools/testing/selftests/kvm/kvm_create_max_vcpus.c +++ b/tools/testing/selftests/kvm/kvm_create_max_vcpus.c @@ -12,6 +12,7 @@ #include #include #include +#include #include "test_util.h" @@ -43,10 +44,39 @@ int main(int argc, char *argv[]) { int kvm_max_vcpu_id = kvm_check_cap(KVM_CAP_MAX_VCPU_ID); int kvm_max_vcpus = kvm_check_cap(KVM_CAP_MAX_VCPUS); + /* + * Number of file descriptors reqired, KVM_CAP_MAX_VCPUS for vCPU fds + + * an arbitrary number for everything else. + */ + int nr_fds_wanted = kvm_max_vcpus + 100; + struct rlimit rl; printf("KVM_CAP_MAX_VCPU_ID: %d\n", kvm_max_vcpu_id); printf("KVM_CAP_MAX_VCPUS: %d\n", kvm_max_vcpus); + /* + * Check that we're allowed to open nr_fds_wanted file descriptors and + * try raising the limits if needed. + */ + TEST_ASSERT(!getrlimit(RLIMIT_NOFILE, &rl), "getrlimit() failed!"); + + if (rl.rlim_cur < nr_fds_wanted) { + rl.rlim_cur = nr_fds_wanted; + if (rl.rlim_max < nr_fds_wanted) { + int old_rlim_max = rl.rlim_max; + rl.rlim_max = nr_fds_wanted; + + int r = setrlimit(RLIMIT_NOFILE, &rl); + if (r < 0) { + printf("RLIMIT_NOFILE hard limit is too low (%d, wanted %d)\n", + old_rlim_max, nr_fds_wanted); + exit(KSFT_SKIP); + } + } else { + TEST_ASSERT(!setrlimit(RLIMIT_NOFILE, &rl), "setrlimit() failed!"); + } + } + /* * Upstream KVM prior to 4.8 does not support KVM_CAP_MAX_VCPU_ID. * Userspace is supposed to use KVM_CAP_MAX_VCPUS as the maximum ID -- 2.33.0