From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 7785320F96B; Thu, 23 Jan 2025 14:20:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737642022; cv=none; b=fUBIsfxBwtHqsPIK/IDEGjY6d6lSUzmqVhtRbWYwF5f+QRKh6HSZoVlKO2lHNIAGkL4ypyFJ8psdk6Bdr9El0a/mbfh1qoY+Xq3JQNghP+RjBwaWL+IH+wbdQpIKzBV8G0zei7UkzSSMFwvOXw6Mg0YOQfDbT4NiWfMh5HjBLlY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737642022; c=relaxed/simple; bh=0XgpFNiqBrZwOPcOSQr6PpF8QuiHUlFjdT+D+/Io9JU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=pmcYtqKuHuHwPJyoputgxevZ8MLeefZz2xVUYA1GGvqV4QZaUm2v9RD3YPMfbRsZ8EN2fI+KTuMvGzOjwK4STa58TBr6NUzMYex/ropSc6qp89kgsxMB5Se+AwQyF5jGfpQ9iCZS3/GSb9Vjic5h816qQzwvyfBzNT+TcnEKKsA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id B3FE41063; Thu, 23 Jan 2025 06:20:45 -0800 (PST) Received: from raptor (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 547893F694; Thu, 23 Jan 2025 06:20:14 -0800 (PST) Date: Thu, 23 Jan 2025 14:20:07 +0000 From: Alexandru Elisei To: Andrew Jones Cc: eric.auger@redhat.com, lvivier@redhat.com, thuth@redhat.com, frankja@linux.ibm.com, imbrenda@linux.ibm.com, nrb@linux.ibm.com, david@redhat.com, pbonzini@redhat.com, kvm@vger.kernel.org, kvmarm@lists.linux.dev, linuxppc-dev@lists.ozlabs.org, kvm-riscv@lists.infradead.org, linux-s390@vger.kernel.org, will@kernel.org, julien.thierry.kdev@gmail.com, maz@kernel.org, oliver.upton@linux.dev, suzuki.poulose@arm.com, yuzenghui@huawei.com, joey.gouly@arm.com, andre.przywara@arm.com Subject: Re: [kvm-unit-tests PATCH v2 12/18] scripts/runtime: Add default arguments for kvmtool Message-ID: References: <20250120164316.31473-1-alexandru.elisei@arm.com> <20250120164316.31473-13-alexandru.elisei@arm.com> <20250121-16510b161f5b92ce9c5ae4e1@orel> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250121-16510b161f5b92ce9c5ae4e1@orel> Hi, On Thu, Jan 23, 2025 at 03:07:18PM +0100, Andrew Jones wrote: > On Mon, Jan 20, 2025 at 04:43:10PM +0000, Alexandru Elisei wrote: > > kvmtool, unless told otherwise, will do its best to make sure that a kernel > > successfully boots in a virtual machine. Among things like automatically > > creating a rootfs, it also adds extra parameters to the kernel command > > line. This is actively harmful to kvm-unit-tests, because some tests parse > > the kernel command line and they will fail if they encounter the options > > added by kvmtool. > > > > Fortunately for us, kvmtool commit 5613ae26b998 ("Add --nodefaults command > > line argument") addded the --nodefaults kvmtool parameter which disables > > added > > > all the implicit virtual machine configuration that cannot be disabled by > > using other parameters, like modifying the kernel command line. Always use > > --nodefaults to allow a test to run. > > > > kvmtool can be too verbose when running a virtual machine, and this is > > controlled with parameters. Add those to the default kvmtool command line > > to reduce this verbosity to a minimum. > > > > Before: > > > > $ vm run arm/selftest.flat --cpus 2 --mem 256 --params "setup smp=2 mem=256" > > Info: # lkvm run -k arm/selftest.flat -m 256 -c 2 --name guest-5035 > > Unknown subtest > > > > EXIT: STATUS=127 > > Warning: KVM compatibility warning. > > virtio-9p device was not detected. > > While you have requested a virtio-9p device, the guest kernel did not initialize it. > > Please make sure that the guest kernel was compiled with CONFIG_NET_9P_VIRTIO=y enabled in .config. > > Warning: KVM compatibility warning. > > virtio-net device was not detected. > > While you have requested a virtio-net device, the guest kernel did not initialize it. > > Please make sure that the guest kernel was compiled with CONFIG_VIRTIO_NET=y enabled in .config. > > Info: KVM session ended normally. > > > > After: > > > > $ vm run arm/selftest.flat --nodefaults --network mode=none --loglevel=warning --cpus 2 --mem 256 --params "setup smp=2 mem=256" > > On riscv I've noticed that with --nodefaults if I don't add parameters > with --params then kvmtool segfaults. I have to add --params "" to > avoid it. Does that also happen on arm? Anyway, that's something we > should fix in kvmtool rather than workaround it here. This should fix it: diff --git a/riscv/fdt.c b/riscv/fdt.c index 85c8f95604f6..f6a702533258 100644 --- a/riscv/fdt.c +++ b/riscv/fdt.c @@ -256,9 +256,10 @@ static int setup_fdt(struct kvm *kvm) if (kvm->cfg.kernel_cmdline) _FDT(fdt_property_string(fdt, "bootargs", kvm->cfg.kernel_cmdline)); - } else + } else if (kvm->cfg.real_cmdline) { _FDT(fdt_property_string(fdt, "bootargs", kvm->cfg.real_cmdline)); + } _FDT(fdt_property_string(fdt, "stdout-path", "serial0")); Looking at the timestamp on the commit, the patch that added --nodefaults came before the patch that added riscv to kvmtool (by about a month). Just in case you want to add a Fixes tag. Thanks, Alex