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 8BDEAC4332F for ; Wed, 14 Dec 2022 10:10:46 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1p5Oi9-0007iR-BJ; Wed, 14 Dec 2022 05:10:01 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1p5Ohr-0007cA-Dx for qemu-devel@nongnu.org; Wed, 14 Dec 2022 05:09:47 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1p5Ohe-00015I-GS for qemu-devel@nongnu.org; Wed, 14 Dec 2022 05:09:34 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1671012561; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=k/lpCYBXIRzEJL16dt1SG350wajOBOqN5P7sPMMQaJM=; b=CQiLKF9Y7A8yAXFehDv9KGzUUkQ6TjVwJqxTGp6Ot/GxEole9LglG92vCUCNvBpMilX1if P25AmDTn84w/VESD06+QEDVVVNiaxrMM5aBBuOPHct1uj/vYh2Wq5OcJhNKq3kCYJ2qQWO QxdvpeJoWkIAnu3i71WqIAA7AxYFZA4= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-581-_A2g6N8OOaOy7_jJV-0ckA-1; Wed, 14 Dec 2022 05:09:19 -0500 X-MC-Unique: _A2g6N8OOaOy7_jJV-0ckA-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id DAACB1C0896E; Wed, 14 Dec 2022 10:09:18 +0000 (UTC) Received: from thuth.com (unknown [10.39.193.57]) by smtp.corp.redhat.com (Postfix) with ESMTP id BD71F492C14; Wed, 14 Dec 2022 10:09:17 +0000 (UTC) From: Thomas Huth To: Stefan Hajnoczi , qemu-devel@nongnu.org Cc: Matthew Rosato , Eric Farman Subject: [PULL 01/23] s390x/pci: coalesce unmap operations Date: Wed, 14 Dec 2022 11:08:49 +0100 Message-Id: <20221214100911.165291-2-thuth@redhat.com> In-Reply-To: <20221214100911.165291-1-thuth@redhat.com> References: <20221214100911.165291-1-thuth@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.9 Received-SPF: pass client-ip=170.10.129.124; envelope-from=thuth@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, 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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org From: Matthew Rosato Currently, each unmapped page is handled as an individual iommu region notification. Attempt to group contiguous unmap operations into fewer notifications to reduce overhead. Signed-off-by: Matthew Rosato Message-Id: <20221028194758.204007-3-mjrosato@linux.ibm.com> Reviewed-by: Eric Farman Signed-off-by: Thomas Huth --- hw/s390x/s390-pci-inst.c | 51 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) diff --git a/hw/s390x/s390-pci-inst.c b/hw/s390x/s390-pci-inst.c index 7cc4bcf850..66e764f901 100644 --- a/hw/s390x/s390-pci-inst.c +++ b/hw/s390x/s390-pci-inst.c @@ -640,6 +640,8 @@ static uint32_t s390_pci_update_iotlb(S390PCIIOMMU *iommu, } g_hash_table_remove(iommu->iotlb, &entry->iova); inc_dma_avail(iommu); + /* Don't notify the iommu yet, maybe we can bundle contiguous unmaps */ + goto out; } else { if (cache) { if (cache->perm == entry->perm && @@ -663,15 +665,44 @@ static uint32_t s390_pci_update_iotlb(S390PCIIOMMU *iommu, dec_dma_avail(iommu); } + /* + * All associated iotlb entries have already been cleared, trigger the + * unmaps. + */ memory_region_notify_iommu(&iommu->iommu_mr, 0, event); out: return iommu->dma_limit ? iommu->dma_limit->avail : 1; } +static void s390_pci_batch_unmap(S390PCIIOMMU *iommu, uint64_t iova, + uint64_t len) +{ + uint64_t remain = len, start = iova, end = start + len - 1, mask, size; + IOMMUTLBEvent event = { + .type = IOMMU_NOTIFIER_UNMAP, + .entry = { + .target_as = &address_space_memory, + .translated_addr = 0, + .perm = IOMMU_NONE, + }, + }; + + while (remain >= TARGET_PAGE_SIZE) { + mask = dma_aligned_pow2_mask(start, end, 64); + size = mask + 1; + event.entry.iova = start; + event.entry.addr_mask = mask; + memory_region_notify_iommu(&iommu->iommu_mr, 0, event); + start += size; + remain -= size; + } +} + int rpcit_service_call(S390CPU *cpu, uint8_t r1, uint8_t r2, uintptr_t ra) { CPUS390XState *env = &cpu->env; + uint64_t iova, coalesce = 0; uint32_t fh; uint16_t error = 0; S390PCIBusDevice *pbdev; @@ -742,6 +773,21 @@ int rpcit_service_call(S390CPU *cpu, uint8_t r1, uint8_t r2, uintptr_t ra) break; } + /* + * If this is an unmap of a PTE, let's try to coalesce multiple unmaps + * into as few notifier events as possible. + */ + if (entry.perm == IOMMU_NONE && entry.len == TARGET_PAGE_SIZE) { + if (coalesce == 0) { + iova = entry.iova; + } + coalesce += entry.len; + } else if (coalesce > 0) { + /* Unleash the coalesced unmap before processing a new map */ + s390_pci_batch_unmap(iommu, iova, coalesce); + coalesce = 0; + } + start += entry.len; while (entry.iova < start && entry.iova < end) { if (dma_avail > 0 || entry.perm == IOMMU_NONE) { @@ -759,6 +805,11 @@ int rpcit_service_call(S390CPU *cpu, uint8_t r1, uint8_t r2, uintptr_t ra) } } } + if (coalesce) { + /* Unleash the coalesced unmap before finishing rpcit */ + s390_pci_batch_unmap(iommu, iova, coalesce); + coalesce = 0; + } if (again && dma_avail > 0) goto retry; err: -- 2.31.1