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 X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_2 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1851AC5DF63 for ; Wed, 6 Nov 2019 16:49:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E698E2166E for ; Wed, 6 Nov 2019 16:49:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729079AbfKFQt2 (ORCPT ); Wed, 6 Nov 2019 11:49:28 -0500 Received: from foss.arm.com ([217.140.110.172]:43068 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728832AbfKFQt1 (ORCPT ); Wed, 6 Nov 2019 11:49:27 -0500 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 EB0E746A; Wed, 6 Nov 2019 08:49:26 -0800 (PST) Received: from donnerap.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id E3D833F719; Wed, 6 Nov 2019 08:49:25 -0800 (PST) Date: Wed, 6 Nov 2019 16:49:23 +0000 From: Andre Przywara To: Alexandru Elisei Cc: kvm@vger.kernel.org, Will Deacon , Julien Thierry , Marc Zyngier , Suzuki Poulose , Julien Grall Subject: Re: [PATCH kvmtool 06/16] builtin-run.c: Always use ram_size in bytes Message-ID: <20191106164923.1d501e9a@donnerap.cambridge.arm.com> In-Reply-To: <1569245722-23375-7-git-send-email-alexandru.elisei@arm.com> References: <1569245722-23375-1-git-send-email-alexandru.elisei@arm.com> <1569245722-23375-7-git-send-email-alexandru.elisei@arm.com> Organization: ARM X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; aarch64-unknown-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Mon, 23 Sep 2019 14:35:12 +0100 Alexandru Elisei wrote: Hi, > The user can specify the virtual machine memory size, in MB, which is saved > in cfg->ram_size. kvmtool validates it against the host memory size, > converted from bytes to MB. ram_size is aftwerwards converted to bytes, and > this is how it is used throughout the rest of the program. > > Let's avoid any confusion about the unit of measurement and always use > cfg->ram_size in bytes. ... which also means you can get rid of MIN_RAM_SIZE_MB in include/kvm/kvm-config.h. Otherwise: > Signed-off-by: Alexandru Elisei Reviewed-by: Andre Przywara Cheers, Andre > --- > builtin-run.c | 19 ++++++++++--------- > include/kvm/kvm-config.h | 2 +- > include/kvm/kvm.h | 2 +- > 3 files changed, 12 insertions(+), 11 deletions(-) > > diff --git a/builtin-run.c b/builtin-run.c > index cff44047bb1c..4e0c52b3e027 100644 > --- a/builtin-run.c > +++ b/builtin-run.c > @@ -262,7 +262,7 @@ static u64 host_ram_size(void) > return 0; > } > > - return (nr_pages * page_size) >> MB_SHIFT; > + return nr_pages * page_size; > } > > /* > @@ -276,11 +276,11 @@ static u64 get_ram_size(int nr_cpus) > u64 available; > u64 ram_size; > > - ram_size = 64 * (nr_cpus + 3); > + ram_size = (64 * (nr_cpus + 3)) << MB_SHIFT; > > available = host_ram_size() * RAM_SIZE_RATIO; > if (!available) > - available = MIN_RAM_SIZE_MB; > + available = MIN_RAM_SIZE_BYTE; > > if (ram_size > available) > ram_size = available; > @@ -531,13 +531,14 @@ static struct kvm *kvm_cmd_run_init(int argc, const char **argv) > > if (!kvm->cfg.ram_size) > kvm->cfg.ram_size = get_ram_size(kvm->cfg.nrcpus); > + else > + /* The user specifies the memory in MB. */ > + kvm->cfg.ram_size <<= MB_SHIFT; > > if (kvm->cfg.ram_size > host_ram_size()) > pr_warning("Guest memory size %lluMB exceeds host physical RAM size %lluMB", > - (unsigned long long)kvm->cfg.ram_size, > - (unsigned long long)host_ram_size()); > - > - kvm->cfg.ram_size <<= MB_SHIFT; > + (unsigned long long)kvm->cfg.ram_size >> MB_SHIFT, > + (unsigned long long)host_ram_size() >> MB_SHIFT); > > if (!kvm->cfg.dev) > kvm->cfg.dev = DEFAULT_KVM_DEV; > @@ -647,12 +648,12 @@ static struct kvm *kvm_cmd_run_init(int argc, const char **argv) > if (kvm->cfg.kernel_filename) { > printf(" # %s run -k %s -m %Lu -c %d --name %s\n", KVM_BINARY_NAME, > kvm->cfg.kernel_filename, > - (unsigned long long)kvm->cfg.ram_size / 1024 / 1024, > + (unsigned long long)kvm->cfg.ram_size >> MB_SHIFT, > kvm->cfg.nrcpus, kvm->cfg.guest_name); > } else if (kvm->cfg.firmware_filename) { > printf(" # %s run --firmware %s -m %Lu -c %d --name %s\n", KVM_BINARY_NAME, > kvm->cfg.firmware_filename, > - (unsigned long long)kvm->cfg.ram_size / 1024 / 1024, > + (unsigned long long)kvm->cfg.ram_size >> MB_SHIFT, > kvm->cfg.nrcpus, kvm->cfg.guest_name); > } > > diff --git a/include/kvm/kvm-config.h b/include/kvm/kvm-config.h > index a052b0bc7582..e0c9ee14e103 100644 > --- a/include/kvm/kvm-config.h > +++ b/include/kvm/kvm-config.h > @@ -22,7 +22,7 @@ struct kvm_config { > struct kvm_config_arch arch; > struct disk_image_params disk_image[MAX_DISK_IMAGES]; > struct vfio_device_params *vfio_devices; > - u64 ram_size; > + u64 ram_size; /* Guest memory size, in bytes */ > u8 image_count; > u8 num_net_devices; > u8 num_vfio_devices; > diff --git a/include/kvm/kvm.h b/include/kvm/kvm.h > index 635ce0f40b1e..a866d5a825c4 100644 > --- a/include/kvm/kvm.h > +++ b/include/kvm/kvm.h > @@ -68,7 +68,7 @@ struct kvm { > struct kvm_cpu **cpus; > > u32 mem_slots; /* for KVM_SET_USER_MEMORY_REGION */ > - u64 ram_size; > + u64 ram_size; /* Guest memory size, in bytes */ > void *ram_start; > u64 ram_pagesize; > struct list_head mem_banks;