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 58D7D155A3C for ; Wed, 28 Aug 2024 06:16:00 +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=1724825764; cv=none; b=TTwnk2NeI8OOvcWsLexbpd2Q2wA4hoNdDxhiRhTUx2jzY8G5hkABfmffUdU8p+S2PAohFr5MUTDwycMOq1Wfm1WmejfNdebHS94ZG+0f7rrGu2HVSq2n/jO7A5gmGmnHKlxPwo+psQMY78CUww3GjPheYjSC1RlqL5Zzj6mY9MA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724825764; c=relaxed/simple; bh=KT+TwnUNQJxTTFJcO7//3nB2g4ynI7vEvQsuTqLFJKM=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=NizM9dWPV3A5r0JFL0eJKp92u6mZ4SzsEPTjp2+kzN5vIVIZ6YipUvubHnq3sEcsB3jn7wm076fvzYUMEyZ+4a3JdG841UzDZlNF79LiNTtTPC6tigydWawj5MbF7NWlEeRMh80S+i0SapxfdgTVRZJr9o7pU/WuHxnxieWKdeM= 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=OtK58o9r; 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="OtK58o9r" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1724825758; 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=anw0eiHHc6iVRnxYqeB3eFZ+/gHPOJF7vc2zFd6U/Kw=; b=OtK58o9rXs6tWGaN4pbNeNcai7I3UDQDrGEW8xq72lgleLOM9u5+NMa5hBnm0B3608OS7h BT+sXM0eNIRSrka30H9pN2CEXLTJSJ7HIFnt7KJ6sPTyFxw/1hNEpr1X4DzassKvH8RRqQ e/6IjVYS3Ucc9hmbcQuGUh550u3Npvw= Received: from mx-prod-mc-02.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-164-W2B2JnpeMkSzIa3lYii-HQ-1; Wed, 28 Aug 2024 02:15:55 -0400 X-MC-Unique: W2B2JnpeMkSzIa3lYii-HQ-1 Received: from mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.40]) (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-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 253411955BED; Wed, 28 Aug 2024 06:15:51 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.39.192.112]) by mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 6816F19560A3; Wed, 28 Aug 2024 06:15:50 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 241C621E6A28; Wed, 28 Aug 2024 08:15:48 +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 v4 1/2] kvm: replace fprintf with error_report/printf() in kvm_init() In-Reply-To: <20240827151022.37992-2-anisinha@redhat.com> (Ani Sinha's message of "Tue, 27 Aug 2024 20:40:21 +0530") References: <20240827151022.37992-1-anisinha@redhat.com> <20240827151022.37992-2-anisinha@redhat.com> Date: Wed, 28 Aug 2024 08:15:48 +0200 Message-ID: <87wmk1fa0b.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 10.30.177.40 Ani Sinha writes: > error_report() is more appropriate for error situations. Replace fprintf with > error_report. Cosmetic. No functional change. > > 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. > > diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c > index 75d11a07b2..d9f477bb06 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"); The use of %m gave me pause. It's a GNU extension, but this Linux-specific code, so it's fine. > 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) if (object_property_find(OBJECT(current_machine), "kvm-type")) { g_autofree char *kvm_type = object_property_get_str(OBJECT(current_machine), "kvm-type", &error_abort); type = mc->kvm_type(ms, kvm_type); } else if (mc->kvm_type) { type = mc->kvm_type(ms, NULL); } else { type = kvm_arch_get_default_type(ms); } if (type < 0) { ret = -EINVAL; goto err; Note: the code assigning to @type is responsible for reporting an error when it assigns a negative value. I guess it does. Even if it doesn't, not your patch's problem. } do { ret = kvm_ioctl(s, KVM_CREATE_VM, type); > } 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: %d %s", -ret, > + strerror(-ret)); We don't normally report a numeric errno code in additon to its description text. Should we use the opportunity to drop it here? > > #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:"); > + error_printf("\n- for kernels supporting the" Please keep the \n at the end of the string literal: 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"); Opportunity to break this line like we break the others: 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); Not this patch's problem, but why do we exit(1) here? > } > } > @@ -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_printf("kvm does not support %s\n%s", > + missing_cap->name, upgrade_note); This is an error message, so it should be marked as such: error_report("kvm does not support %s", missing_cap->name); error_printf("%s", upgrade_note); > goto err; > } There are a few more uses of fprintf() for reporting errors in kvm.c. Would be nice to have them cleaned up. This is not a demand.