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=-19.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 88E06C433DB for ; Wed, 23 Dec 2020 03:45:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 59A83223E0 for ; Wed, 23 Dec 2020 03:45:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727663AbgLWDpT (ORCPT ); Tue, 22 Dec 2020 22:45:19 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:55100 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726969AbgLWDpT (ORCPT ); Tue, 22 Dec 2020 22:45:19 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1608695031; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=qsuv3WIE0jGMcj/BxF2Qwigx9EzOriMzU8akSMUha9g=; b=hcFe3KKT3Ded6VFYzxY0+ky2c4KsP3VAUWbPrhHrC46WAydGOotua1QVj2C46hOKcuuDc6 COiOPiPl30lHMMUNMndUUPPayP2oMYwwDyoF7ULk/Yieyg8obb/IbYrHKTWVYZV4ZTqpAE PTjWj+4IMZ55dILfNT0bTsnc03XjoHw= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-344-tV3rUBuOPR6WYIPQz3lJWA-1; Tue, 22 Dec 2020 22:43:47 -0500 X-MC-Unique: tV3rUBuOPR6WYIPQz3lJWA-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id BEDC2800D53; Wed, 23 Dec 2020 03:43:46 +0000 (UTC) Received: from [10.72.13.89] (ovpn-13-89.pek2.redhat.com [10.72.13.89]) by smtp.corp.redhat.com (Postfix) with ESMTP id 905315FC3A; Wed, 23 Dec 2020 03:43:41 +0000 (UTC) Subject: Re: [PATCH] vdpa_sim: use iova module to allocate IOVA addresses To: Stefano Garzarella , virtualization@lists.linux-foundation.org Cc: linux-kernel@vger.kernel.org, Max Gurtovoy , Laurent Vivier , "Michael S. Tsirkin" References: <20201222174551.133678-1-sgarzare@redhat.com> From: Jason Wang Message-ID: Date: Wed, 23 Dec 2020 11:43:40 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20201222174551.133678-1-sgarzare@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020/12/23 上午1:45, Stefano Garzarella wrote: > The identical mapping used until now created issues when mapping > different virtual pages with the same physical address. > To solve this issue, we can use the iova module, to handle the IOVA > allocation. > For semplicity we use an IOVA allocator with byte granularity. Should be simplicity, so did one comment below. > > We add two new functions, vdpasim_map_range() and vdpasim_unmap_range(), > to handle the IOVA allocation and the registration into the IOMMU/IOTLB. > These functions are used by dma_map_ops callbacks. > > Signed-off-by: Stefano Garzarella Few nits, but: Acked-by: Jason Wang > --- > drivers/vdpa/vdpa_sim/vdpa_sim.h | 2 + > drivers/vdpa/vdpa_sim/vdpa_sim.c | 108 +++++++++++++++++++------------ > drivers/vdpa/Kconfig | 1 + > 3 files changed, 69 insertions(+), 42 deletions(-) > > diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.h b/drivers/vdpa/vdpa_sim/vdpa_sim.h > index b02142293d5b..6efe205e583e 100644 > --- a/drivers/vdpa/vdpa_sim/vdpa_sim.h > +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.h > @@ -6,6 +6,7 @@ > #ifndef _VDPA_SIM_H > #define _VDPA_SIM_H > > +#include > #include > #include > #include > @@ -55,6 +56,7 @@ struct vdpasim { > /* virtio config according to device type */ > void *config; > struct vhost_iotlb *iommu; > + struct iova_domain iova; > void *buffer; > u32 status; > u32 generation; > diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c > index b3fcc67bfdf0..341b9daf2ea4 100644 > --- a/drivers/vdpa/vdpa_sim/vdpa_sim.c > +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c > @@ -17,6 +17,7 @@ > #include > #include > #include > +#include > > #include "vdpa_sim.h" > > @@ -128,30 +129,57 @@ static int dir_to_perm(enum dma_data_direction dir) > return perm; > } > > +static dma_addr_t vdpasim_map_range(struct vdpasim *vdpasim, phys_addr_t paddr, > + size_t size, unsigned int perm) > +{ > + struct iova *iova; > + dma_addr_t dma_addr; > + int ret; > + > + /* We set the limit_pfn to the maximum (~0UL - 1) */ > + iova = alloc_iova(&vdpasim->iova, size, ~0UL - 1, true); Let's use ULONG_MAX? > + if (!iova) > + return DMA_MAPPING_ERROR; > + > + dma_addr = iova_dma_addr(&vdpasim->iova, iova); > + > + spin_lock(&vdpasim->iommu_lock); > + ret = vhost_iotlb_add_range(vdpasim->iommu, (u64)dma_addr, > + (u64)dma_addr + size - 1, (u64)paddr, perm); > + spin_unlock(&vdpasim->iommu_lock); > + > + if (ret) { > + __free_iova(&vdpasim->iova, iova); > + return DMA_MAPPING_ERROR; > + } > + > + return dma_addr; > +} > + > +static void vdpasim_unmap_range(struct vdpasim *vdpasim, dma_addr_t dma_addr, > + size_t size) > +{ > + spin_lock(&vdpasim->iommu_lock); > + vhost_iotlb_del_range(vdpasim->iommu, (u64)dma_addr, > + (u64)dma_addr + size - 1); > + spin_unlock(&vdpasim->iommu_lock); > + > + free_iova(&vdpasim->iova, iova_pfn(&vdpasim->iova, dma_addr)); > +} > + > static dma_addr_t vdpasim_map_page(struct device *dev, struct page *page, > unsigned long offset, size_t size, > enum dma_data_direction dir, > unsigned long attrs) > { > struct vdpasim *vdpasim = dev_to_sim(dev); > - struct vhost_iotlb *iommu = vdpasim->iommu; > - u64 pa = (page_to_pfn(page) << PAGE_SHIFT) + offset; > - int ret, perm = dir_to_perm(dir); > + phys_addr_t paddr = page_to_phys(page) + offset; > + int perm = dir_to_perm(dir); > > if (perm < 0) > return DMA_MAPPING_ERROR; > > - /* For simplicity, use identical mapping to avoid e.g iova > - * allocator. > - */ > - spin_lock(&vdpasim->iommu_lock); > - ret = vhost_iotlb_add_range(iommu, pa, pa + size - 1, > - pa, dir_to_perm(dir)); > - spin_unlock(&vdpasim->iommu_lock); > - if (ret) > - return DMA_MAPPING_ERROR; > - > - return (dma_addr_t)(pa); > + return vdpasim_map_range(vdpasim, paddr, size, perm); > } > > static void vdpasim_unmap_page(struct device *dev, dma_addr_t dma_addr, > @@ -159,12 +187,8 @@ static void vdpasim_unmap_page(struct device *dev, dma_addr_t dma_addr, > unsigned long attrs) > { > struct vdpasim *vdpasim = dev_to_sim(dev); > - struct vhost_iotlb *iommu = vdpasim->iommu; > > - spin_lock(&vdpasim->iommu_lock); > - vhost_iotlb_del_range(iommu, (u64)dma_addr, > - (u64)dma_addr + size - 1); > - spin_unlock(&vdpasim->iommu_lock); > + vdpasim_unmap_range(vdpasim, dma_addr, size); > } > > static void *vdpasim_alloc_coherent(struct device *dev, size_t size, > @@ -172,27 +196,22 @@ static void *vdpasim_alloc_coherent(struct device *dev, size_t size, > unsigned long attrs) > { > struct vdpasim *vdpasim = dev_to_sim(dev); > - struct vhost_iotlb *iommu = vdpasim->iommu; > - void *addr = kmalloc(size, flag); > - int ret; > + phys_addr_t paddr; > + void *addr; > > - spin_lock(&vdpasim->iommu_lock); > + addr = kmalloc(size, flag); > if (!addr) { > *dma_addr = DMA_MAPPING_ERROR; > - } else { > - u64 pa = virt_to_phys(addr); > - > - ret = vhost_iotlb_add_range(iommu, (u64)pa, > - (u64)pa + size - 1, > - pa, VHOST_MAP_RW); > - if (ret) { > - *dma_addr = DMA_MAPPING_ERROR; > - kfree(addr); > - addr = NULL; > - } else > - *dma_addr = (dma_addr_t)pa; > + return NULL; > + } > + > + paddr = virt_to_phys(addr); > + > + *dma_addr = vdpasim_map_range(vdpasim, paddr, size, VHOST_MAP_RW); > + if (*dma_addr == DMA_MAPPING_ERROR) { > + kfree(addr); > + return NULL; > } > - spin_unlock(&vdpasim->iommu_lock); > > return addr; > } > @@ -202,14 +221,10 @@ static void vdpasim_free_coherent(struct device *dev, size_t size, > unsigned long attrs) > { > struct vdpasim *vdpasim = dev_to_sim(dev); > - struct vhost_iotlb *iommu = vdpasim->iommu; > > - spin_lock(&vdpasim->iommu_lock); > - vhost_iotlb_del_range(iommu, (u64)dma_addr, > - (u64)dma_addr + size - 1); > - spin_unlock(&vdpasim->iommu_lock); > + vdpasim_unmap_range(vdpasim, dma_addr, size); > > - kfree(phys_to_virt((uintptr_t)dma_addr)); > + kfree(vaddr); > } > > static const struct dma_map_ops vdpasim_dma_ops = { > @@ -270,6 +285,13 @@ struct vdpasim *vdpasim_create(struct vdpasim_dev_attr *dev_attr) > for (i = 0; i < dev_attr->nvqs; i++) > vringh_set_iotlb(&vdpasim->vqs[i].vring, vdpasim->iommu); > > + ret = iova_cache_get(); > + if (ret) > + goto err_iommu; > + > + /* For semplicity we use an IOVA allocator with byte granularity */ Should be simplicity. Thanks > + init_iova_domain(&vdpasim->iova, 1, 0); > + > vdpasim->vdpa.dma_dev = dev; > > return vdpasim; > @@ -540,6 +562,8 @@ static void vdpasim_free(struct vdpa_device *vdpa) > struct vdpasim *vdpasim = vdpa_to_sim(vdpa); > > cancel_work_sync(&vdpasim->work); > + put_iova_domain(&vdpasim->iova); > + iova_cache_put(); > kvfree(vdpasim->buffer); > if (vdpasim->iommu) > vhost_iotlb_free(vdpasim->iommu); > diff --git a/drivers/vdpa/Kconfig b/drivers/vdpa/Kconfig > index 92a6396f8a73..8965e3717231 100644 > --- a/drivers/vdpa/Kconfig > +++ b/drivers/vdpa/Kconfig > @@ -13,6 +13,7 @@ config VDPA_SIM > depends on RUNTIME_TESTING_MENU && HAS_DMA > select DMA_OPS > select VHOST_RING > + select IOMMU_IOVA > help > Enable this module to support vDPA device simulators. These devices > are used for testing, prototyping and development of vDPA.