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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 236A4C04A95 for ; Wed, 28 Sep 2022 23:39:20 +0000 (UTC) Received: from localhost ([::1]:42848 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1odge7-0001jF-2z for qemu-devel@archiver.kernel.org; Wed, 28 Sep 2022 19:39:19 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:49920) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1odgd1-0000ow-6t for qemu-devel@nongnu.org; Wed, 28 Sep 2022 19:38:11 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:42226) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1odgcx-0003Nl-TJ for qemu-devel@nongnu.org; Wed, 28 Sep 2022 19:38:09 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1664408287; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=lapJ13xQyXWjVW+b+BLgO3UNxEdHHe+9PvkX6MCIbjE=; b=QpPA0iu5SK+T6784UBSgN95XXd8EFncbmQ9cZDde2IYZqIMwTPF09ogbNAo7baMQzDQnCh 881EaS6/6x7Nw4kO2h0FtiX4iFaXhuxto/UlzxzmvvJg4ZOhIbPiLw5QZAsa1bW6x1QL59 ieiMJvKGXJPlTs+shNEYNMz3bCgWPl0= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-138-9DJAd7MjNqScZW95YsGz4g-1; Wed, 28 Sep 2022 19:38:03 -0400 X-MC-Unique: 9DJAd7MjNqScZW95YsGz4g-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 761F7802801; Wed, 28 Sep 2022 23:38:03 +0000 (UTC) Received: from [10.64.54.143] (vpn2-54-143.bne.redhat.com [10.64.54.143]) by smtp.corp.redhat.com (Postfix) with ESMTPS id D15DA40C206B; Wed, 28 Sep 2022 23:37:59 +0000 (UTC) Subject: Re: [PATCH v3 4/5] hw/arm/virt: Improve high memory region address assignment To: eric.auger@redhat.com, qemu-arm@nongnu.org Cc: qemu-devel@nongnu.org, maz@kernel.org, cohuck@redhat.com, zhenyzha@redhat.com, richard.henderson@linaro.org, peter.maydell@linaro.org, shan.gavin@gmail.com References: <20220921231349.274049-1-gshan@redhat.com> <20220921231349.274049-5-gshan@redhat.com> <6c9a644a-6add-af29-8463-eddb101c1c99@redhat.com> From: Gavin Shan Message-ID: <580f5f69-d794-3792-2c99-5cb367a5e8c0@redhat.com> Date: Thu, 29 Sep 2022 09:37:57 +1000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.0 MIME-Version: 1.0 In-Reply-To: <6c9a644a-6add-af29-8463-eddb101c1c99@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.1 Received-SPF: pass client-ip=170.10.133.124; envelope-from=gshan@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -44 X-Spam_score: -4.5 X-Spam_bar: ---- X-Spam_report: (-4.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-2.319, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Gavin Shan Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Hi Eric, On 9/28/22 10:51 PM, Eric Auger wrote: > On 9/22/22 01:13, Gavin Shan wrote: >> There are three high memory regions, which are VIRT_HIGH_REDIST2, >> VIRT_HIGH_PCIE_ECAM and VIRT_HIGH_PCIE_MMIO. Their base addresses >> are floating on highest RAM address. However, they can be disabled >> in several cases. >> >> (1) One specific high memory region is disabled by developer by >> toggling vms->highmem_{redists, ecam, mmio}. >> >> (2) VIRT_HIGH_PCIE_ECAM region is disabled on machine, which is >> 'virt-2.12' or ealier than it. >> >> (3) VIRT_HIGH_PCIE_ECAM region is disabled when firmware is loaded >> on 32-bits system. >> >> (4) One specific high memory region is disabled when it breaks the >> PA space limit. >> >> The current implementation of virt_set_memmap() isn't comprehensive >> because the space for one specific high memory region is always >> reserved from the PA space for case (1), (2) and (3). In the code, >> 'base' and 'vms->highest_gpa' are always increased for those three >> cases. It's unnecessary since the assigned space of the disabled >> high memory region won't be used afterwards. >> >> This improves the address assignment for those three high memory >> region by skipping the address assignment for one specific high >> memory region if it has been disabled in case (1), (2) and (3). >> >> Signed-off-by: Gavin Shan >> --- >> hw/arm/virt.c | 44 ++++++++++++++++++++++++++------------------ >> 1 file changed, 26 insertions(+), 18 deletions(-) >> >> diff --git a/hw/arm/virt.c b/hw/arm/virt.c >> index b0b679d1f4..b702f8f2b5 100644 >> --- a/hw/arm/virt.c >> +++ b/hw/arm/virt.c >> @@ -1693,15 +1693,31 @@ static void virt_set_high_memmap(VirtMachineState *vms, >> hwaddr base, int pa_bits) >> { >> hwaddr region_base, region_size; >> - bool fits; >> + bool *region_enabled, fits; > IDo you really need a pointer? If the region is unknown this is a bug in > virt code. The pointer is needed so that we can disable the region by setting 'false' to it at later point. Yeah, I think you're correct that 'unknown region' is a bug and we need to do assert(region_enabled), or something like below. >> int i; >> >> for (i = VIRT_LOWMEMMAP_LAST; i < ARRAY_SIZE(extended_memmap); i++) { >> region_base = ROUND_UP(base, extended_memmap[i].size); >> region_size = extended_memmap[i].size; >> >> - vms->memmap[i].base = region_base; >> - vms->memmap[i].size = region_size; >> + switch (i) { >> + case VIRT_HIGH_GIC_REDIST2: >> + region_enabled = &vms->highmem_redists; >> + break; >> + case VIRT_HIGH_PCIE_ECAM: >> + region_enabled = &vms->highmem_ecam; >> + break; >> + case VIRT_HIGH_PCIE_MMIO: >> + region_enabled = &vms->highmem_mmio; >> + break; > While we are at it I would change the vms fields dealing with those > highmem regions and turn those fields into an array of bool indexed > using i - VIRT_LOWMEMMAP_LAST (using a macro or something alike). We > would not be obliged to have this switch, now duplicated. It makes sense to me. How about to have something like below in v4? static inline bool *virt_get_high_memmap_enabled(VirtMachineState *vms, int index) { bool *enabled_array[] = { &vms->highmem_redists, &vms->highmem_ecam, &vms->highmem_mmio, }; assert(index - VIRT_LOWMEMMAP_LAST < ARRAY_SIZE(enabled_array)); return enabled_array[index - VIRT_LOWMEMMAP_LAST]; } >> + default: >> + region_enabled = NULL; >> + } >> + >> + /* Skip unknown region */ >> + if (!region_enabled) { >> + continue; >> + } >> >> /* >> * Check each device to see if they fit in the PA space, >> @@ -1710,23 +1726,15 @@ static void virt_set_high_memmap(VirtMachineState *vms, >> * For each device that doesn't fit, disable it. >> */ >> fits = (region_base + region_size) <= BIT_ULL(pa_bits); >> - if (fits) { >> - vms->highest_gpa = region_base + region_size - 1; >> - } >> + if (*region_enabled && fits) { >> + vms->memmap[i].base = region_base; >> + vms->memmap[i].size = region_size; >> >> - switch (i) { >> - case VIRT_HIGH_GIC_REDIST2: >> - vms->highmem_redists &= fits; >> - break; >> - case VIRT_HIGH_PCIE_ECAM: >> - vms->highmem_ecam &= fits; >> - break; >> - case VIRT_HIGH_PCIE_MMIO: >> - vms->highmem_mmio &= fits; >> - break; >> + vms->highest_gpa = region_base + region_size - 1; >> + base = region_base + region_size; >> + } else { >> + *region_enabled = false; >> } >> - >> - base = region_base + region_size; >> } >> } >> Thanks, Gavin