From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 755BD3FEC for ; Wed, 28 Aug 2024 11:23:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724844199; cv=none; b=sonHqpVjieIEqVqXH699o86LxfrK3dtx7kX34mLX2ohjnfdltoD0pRW+01l3hAt/kExp+3E1S6VOPBr+unhUechm9DH53ihECVQI5MNhGfcv1pw0bBIDZLbGf5wSa7MqPGyW/5YQetV+PATOd72wCmxbb10LKepL7u2S67/J7w8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724844199; c=relaxed/simple; bh=nbPQLzfzYM20rrwCtRiiclAxBxp1BUjK7SM3pjygeuM=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=fACb1nJImvwXuIHLoTJ/T9SaP3VP+2aToG/DIoaXxzCM/nUW91XS3k7jixXdUA88HuP+ByWCYf5VVyeVBuOJkMyChuuRvFg95CfmEhjw+U2A/RXnd5qF0LkS/1OoFkTyROfsTgNuIlAFeYFhBGo3FU1PDSOdS8hzPf5dDIgoUfY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=e5mGa8Qd; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="e5mGa8Qd" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1724844196; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=sjPscny8RpBp/Hq/MF0Txq0RsmBmvhMA9j1IvksC6Zg=; b=e5mGa8QdE95hpQF6Ga2GuAA0gFBc3mNVpX0mROmBDImpqd/h94GJvuDFtZAwdXlXq7RApd dQvfJ+4PA5fqn6o7b4sGzko+RNFpUATdSOQcFOIIVDsgFZUTymApjGHgWBxmvT58i9HMvi 5S4XlNOdfq44BXirc6ovWCLiMLYGyp4= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-644-VVMG9EtQNq6uKZ4tlwC9Sw-1; Wed, 28 Aug 2024 07:23:13 -0400 X-MC-Unique: VVMG9EtQNq6uKZ4tlwC9Sw-1 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 0AB3F1955F4A; Wed, 28 Aug 2024 11:23:12 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.39.192.112]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 151FE19560A3; Wed, 28 Aug 2024 11:23:11 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id E498221E6A28; Wed, 28 Aug 2024 13:23:08 +0200 (CEST) From: Markus Armbruster To: Ani Sinha Cc: Paolo Bonzini , qemu-trivial@nongnu.org, zhao1.liu@intel.com, kvm@vger.kernel.org, qemu-devel@nongnu.org Subject: Re: [PATCH v5 1/2] kvm: replace fprintf with error_report()/printf() in kvm_init() In-Reply-To: <20240828075630.7754-2-anisinha@redhat.com> (Ani Sinha's message of "Wed, 28 Aug 2024 13:26:28 +0530") References: <20240828075630.7754-1-anisinha@redhat.com> <20240828075630.7754-2-anisinha@redhat.com> Date: Wed, 28 Aug 2024 13:23:08 +0200 Message-ID: <87ikvkriw3.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 Ani Sinha writes: > error_report() is more appropriate for error situations. Replace fprintf with > error_report() and error_printf() as appropriate. Cosmetic. No functional > change. Uh, I missed this last time around: the change is more than just cosmetics! The error messages change, e.g. from $ qemu-system-x86_64 -nodefaults -S -display none --accel kvm qemu-system-x86_64: --accel kvm: Could not access KVM kernel module: Permission denied qemu-system-x86_64: --accel kvm: failed to initialize kvm: Permission denied to $ qemu-system-x86_64 -nodefaults -S -display none --accel kvm Could not access KVM kernel module: Permission denied qemu-system-x86_64: --accel kvm: failed to initialize kvm: Permission denied Note: the second message is from kvm_init()'s caller. Reporting the same error twice is wrong, but not this patch's problem. Moreover, the patch tweaks an error message at [*]. Suggest something like Replace fprintf() with error_report() and error_printf() where appropriate. Error messages improve, e.g. from Could not access KVM kernel module: Permission denied to qemu-system-x86_64: --accel kvm: Could not access KVM kernel module: Permission denied > CC: qemu-trivial@nongnu.org > CC: zhao1.liu@intel.com > CC: armbru@redhat.com > Reviewed-by: Zhao Liu > Signed-off-by: Ani Sinha > --- > accel/kvm/kvm-all.c | 40 ++++++++++++++++++---------------------- > 1 file changed, 18 insertions(+), 22 deletions(-) > > changelog: > v2: fix a bug. > v3: replace one instance of error_report() with error_printf(). added tags. > v4: changes suggested by Markus. > v5: more changes from Markus's comments on v4. > > diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c > index 75d11a07b2..fcc157f0e6 100644 > --- a/accel/kvm/kvm-all.c > +++ b/accel/kvm/kvm-all.c > @@ -2427,7 +2427,7 @@ static int kvm_init(MachineState *ms) > QLIST_INIT(&s->kvm_parked_vcpus); > s->fd = qemu_open_old(s->device ?: "/dev/kvm", O_RDWR); > if (s->fd == -1) { > - fprintf(stderr, "Could not access KVM kernel module: %m\n"); > + error_report("Could not access KVM kernel module: %m"); > ret = -errno; > goto err; > } > @@ -2437,13 +2437,13 @@ static int kvm_init(MachineState *ms) > if (ret >= 0) { > ret = -EINVAL; > } > - fprintf(stderr, "kvm version too old\n"); > + error_report("kvm version too old"); > goto err; > } > > if (ret > KVM_API_VERSION) { > ret = -EINVAL; > - fprintf(stderr, "kvm version not supported\n"); > + error_report("kvm version not supported"); > goto err; > } > > @@ -2488,26 +2488,22 @@ static int kvm_init(MachineState *ms) > } while (ret == -EINTR); > > if (ret < 0) { > - fprintf(stderr, "ioctl(KVM_CREATE_VM) failed: %d %s\n", -ret, > - strerror(-ret)); > + error_report("ioctl(KVM_CREATE_VM) failed: %s", strerror(-ret)); [*] This is where you change an error message. > > #ifdef TARGET_S390X > if (ret == -EINVAL) { > - fprintf(stderr, > - "Host kernel setup problem detected. Please verify:\n"); > - fprintf(stderr, "- for kernels supporting the switch_amode or" > - " user_mode parameters, whether\n"); > - fprintf(stderr, > - " user space is running in primary address space\n"); > - fprintf(stderr, > - "- for kernels supporting the vm.allocate_pgste sysctl, " > - "whether it is enabled\n"); > + error_printf("Host kernel setup problem detected." > + " Please verify:\n"); > + error_printf("- for kernels supporting the" > + " switch_amode or user_mode parameters, whether"); > + error_printf(" user space is running in primary address space\n"); > + error_printf("- for kernels supporting the vm.allocate_pgste" > + " sysctl, whether it is enabled\n"); > } > #elif defined(TARGET_PPC) > if (ret == -EINVAL) { > - fprintf(stderr, > - "PPC KVM module is not loaded. Try modprobe kvm_%s.\n", > - (type == 2) ? "pr" : "hv"); > + error_printf("PPC KVM module is not loaded. Try modprobe kvm_%s.\n", > + (type == 2) ? "pr" : "hv"); > } > #endif > goto err; > @@ -2526,9 +2522,9 @@ static int kvm_init(MachineState *ms) > nc->name, nc->num, soft_vcpus_limit); > > if (nc->num > hard_vcpus_limit) { > - fprintf(stderr, "Number of %s cpus requested (%d) exceeds " > - "the maximum cpus supported by KVM (%d)\n", > - nc->name, nc->num, hard_vcpus_limit); > + error_report("Number of %s cpus requested (%d) exceeds " > + "the maximum cpus supported by KVM (%d)", > + nc->name, nc->num, hard_vcpus_limit); > exit(1); > } > } > @@ -2542,8 +2538,8 @@ static int kvm_init(MachineState *ms) > } > if (missing_cap) { > ret = -EINVAL; > - fprintf(stderr, "kvm does not support %s\n%s", > - missing_cap->name, upgrade_note); > + error_report("kvm does not support %s", missing_cap->name); > + error_printf("%s", upgrade_note); > goto err; > } With the commit message corrected: Reviewed-by: Markus Armbruster