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 E024EC433EF for ; Mon, 13 Dec 2021 14:22:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239054AbhLMOWQ (ORCPT ); Mon, 13 Dec 2021 09:22:16 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38368 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239144AbhLMOWK (ORCPT ); Mon, 13 Dec 2021 09:22:10 -0500 Received: from mail-ed1-x52d.google.com (mail-ed1-x52d.google.com [IPv6:2a00:1450:4864:20::52d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8A9FEC061A32; Mon, 13 Dec 2021 06:22:08 -0800 (PST) Received: by mail-ed1-x52d.google.com with SMTP id y12so51857915eda.12; Mon, 13 Dec 2021 06:22:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=sender:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=laxE5jN2bHJG4Yo8WVS4mx5VPDFX4vkop6go8zl/3cQ=; b=lzIwCzNJvV86Boup6xgN3osyOJCZ5s9f7wssi8eyqby4QFK6mgh5w3tsozKTsJ3T59 HVIqizJ9ZFY64dJp6KfX+cGRLOQJEUW1bzqXZGPlZkMjcWmDT+x4qJOaaQciaOAaqqaj HJrg2wpVesDIDnNnXE47hF9u2zKK0yR9ZEIGagxI6LOf8wbifVoIpR3Fzosc7syqYuLg JXWkIw+L3dFwO2b6bI896aMnKTfjnchtLGFfA5Q2ryaFoOBCw6IZ3EdA9NVzgftFprLF ozWGX0Iit8K1FK6gIfGRc+GIN4B5+EySkEsCFz5L1EEVwZq4JtYAomtfuyIuiB/U9+tJ P/7w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:sender:message-id:date:mime-version:user-agent :subject:content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=laxE5jN2bHJG4Yo8WVS4mx5VPDFX4vkop6go8zl/3cQ=; b=7IiiVqeBS/ZVreZhSNvqqYo6G0cqrAe7nz07I4adOtYzRN69/VtWG71RqUPEJoyr35 4ZF6GSjXE5G5OU1LcyDtFvvBaKdjCfYnuXmXPzxD+6eD2KvLA2iNIeJ47THX/hWmq4nX rf5vT+YFT/BmCStmoFCjyu8r3CO21hTN3V8iPKUXLg0i2YTKG0pIWJVEnHObywAql1ch FsIcE6eNIhRkuNxyYnR3Jo6z2cBGM1UTjFEGNKV+v+SieS9d6jk/e4qIqRUcPZ3mxmLG JmAyqG2JBR+4Can3Whz4iINBf9Z3ETPrLQAtSBdTERm7ZcFgxZRGIWECpYplDPon8KJa 1row== X-Gm-Message-State: AOAM530BJIZzKjfZmytkfgLLi1eJp0qb4gHXEn3+pPcwTc57teXSbHoc pQirwkOVmJJt9x71x0bkNZo= X-Google-Smtp-Source: ABdhPJxNFRV6Oi2yANoqjyUMFO8hhvfktf+ywIKoyHutx2WmfJhwBnQg2syM5e7/uYTFHwNnzVsp7g== X-Received: by 2002:a50:d543:: with SMTP id f3mr62764539edj.56.1639405324197; Mon, 13 Dec 2021 06:22:04 -0800 (PST) Received: from ?IPV6:2001:b07:6468:f312:c8dd:75d4:99ab:290a? ([2001:b07:6468:f312:c8dd:75d4:99ab:290a]) by smtp.googlemail.com with ESMTPSA id 12sm147884eja.187.2021.12.13.06.22.01 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 13 Dec 2021 06:22:03 -0800 (PST) Sender: Paolo Bonzini Message-ID: <72a3fabf-bb1d-002f-caaf-2656559aa2a8@redhat.com> Date: Mon, 13 Dec 2021 15:22:01 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.2.0 Subject: Re: [PATCH MANUALSEL 5.10 3/4] KVM: selftests: Make sure kvm_create_max_vcpus test won't hit RLIMIT_NOFILE Content-Language: en-US To: Sasha Levin , linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Vitaly Kuznetsov , Sean Christopherson , shuah@kernel.org, kvm@vger.kernel.org, linux-kselftest@vger.kernel.org References: <20211213142020.352376-1-sashal@kernel.org> <20211213142020.352376-3-sashal@kernel.org> From: Paolo Bonzini In-Reply-To: <20211213142020.352376-3-sashal@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On 12/13/21 15:20, Sasha Levin wrote: > 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 0299cd81b8ba2..aa3795cd7bd3d 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" > > @@ -40,10 +41,39 @@ 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; > > pr_info("KVM_CAP_MAX_VCPU_ID: %d\n", kvm_max_vcpu_id); > pr_info("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 > Acked-by: Paolo Bonzini