From patchwork Wed May 15 19:27:00 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vivek Goyal X-Patchwork-Id: 10945181 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id DC2EF13AD for ; Wed, 15 May 2019 19:29:01 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CDCFA2842D for ; Wed, 15 May 2019 19:29:01 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C194A28541; Wed, 15 May 2019 19:29:01 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4D0C42842D for ; Wed, 15 May 2019 19:29:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727951AbfEOT2r (ORCPT ); Wed, 15 May 2019 15:28:47 -0400 Received: from mx1.redhat.com ([209.132.183.28]:42882 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727266AbfEOT1e (ORCPT ); Wed, 15 May 2019 15:27:34 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 7D84333027E; Wed, 15 May 2019 19:27:33 +0000 (UTC) Received: from horse.redhat.com (unknown [10.18.25.29]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5491B1001DE1; Wed, 15 May 2019 19:27:33 +0000 (UTC) Received: by horse.redhat.com (Postfix, from userid 10451) id C56EC225483; Wed, 15 May 2019 15:27:29 -0400 (EDT) From: Vivek Goyal To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-nvdimm@lists.01.org Cc: vgoyal@redhat.com, miklos@szeredi.hu, stefanha@redhat.com, dgilbert@redhat.com, swhiteho@redhat.com Subject: [PATCH v2 15/30] virtio: Implement get_shm_region for PCI transport Date: Wed, 15 May 2019 15:27:00 -0400 Message-Id: <20190515192715.18000-16-vgoyal@redhat.com> In-Reply-To: <20190515192715.18000-1-vgoyal@redhat.com> References: <20190515192715.18000-1-vgoyal@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Wed, 15 May 2019 19:27:33 +0000 (UTC) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Sebastien Boeuf On PCI the shm regions are found using capability entries; find a region by searching for the capability. Signed-off-by: Sebastien Boeuf Signed-off-by: Dr. David Alan Gilbert --- drivers/virtio/virtio_pci_modern.c | 108 +++++++++++++++++++++++++++++ include/uapi/linux/virtio_pci.h | 10 +++ 2 files changed, 118 insertions(+) diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c index 07571daccfec..51c9e6eca5ac 100644 --- a/drivers/virtio/virtio_pci_modern.c +++ b/drivers/virtio/virtio_pci_modern.c @@ -446,6 +446,112 @@ static void del_vq(struct virtio_pci_vq_info *info) vring_del_virtqueue(vq); } +static int virtio_pci_find_shm_cap(struct pci_dev *dev, + u8 required_id, + u8 *bar, u64 *offset, u64 *len) +{ + int pos; + + for (pos = pci_find_capability(dev, PCI_CAP_ID_VNDR); + pos > 0; + pos = pci_find_next_capability(dev, pos, PCI_CAP_ID_VNDR)) { + u8 type, cap_len, id; + u32 tmp32; + u64 res_offset, res_length; + + pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap, + cfg_type), + &type); + if (type != VIRTIO_PCI_CAP_SHARED_MEMORY_CFG) + continue; + + pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap, + cap_len), + &cap_len); + if (cap_len != sizeof(struct virtio_pci_shm_cap)) { + printk(KERN_ERR "%s: shm cap with bad size offset: %d size: %d\n", + __func__, pos, cap_len); + continue; + }; + + pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_shm_cap, + id), + &id); + if (id != required_id) + continue; + + /* Type, and ID match, looks good */ + pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap, + bar), + bar); + + /* Read the lower 32bit of length and offset */ + pci_read_config_dword(dev, pos + offsetof(struct virtio_pci_cap, offset), + &tmp32); + res_offset = tmp32; + pci_read_config_dword(dev, pos + offsetof(struct virtio_pci_cap, length), + &tmp32); + res_length = tmp32; + + /* and now the top half */ + pci_read_config_dword(dev, + pos + offsetof(struct virtio_pci_shm_cap, + offset_hi), + &tmp32); + res_offset |= ((u64)tmp32) << 32; + pci_read_config_dword(dev, + pos + offsetof(struct virtio_pci_shm_cap, + length_hi), + &tmp32); + res_length |= ((u64)tmp32) << 32; + + *offset = res_offset; + *len = res_length; + + return pos; + } + return 0; +} + +static bool vp_get_shm_region(struct virtio_device *vdev, + struct virtio_shm_region *region, u8 id) +{ + struct virtio_pci_device *vp_dev = to_vp_device(vdev); + struct pci_dev *pci_dev = vp_dev->pci_dev; + u8 bar; + u64 offset, len; + phys_addr_t phys_addr; + size_t bar_len; + char *bar_name; + int ret; + + if (!virtio_pci_find_shm_cap(pci_dev, id, &bar, &offset, &len)) { + return false; + } + + ret = pci_request_region(pci_dev, bar, "virtio-pci-shm"); + if (ret < 0) { + dev_err(&pci_dev->dev, "%s: failed to request BAR\n", + __func__); + return false; + } + + phys_addr = pci_resource_start(pci_dev, bar); + bar_len = pci_resource_len(pci_dev, bar); + + if (offset + len > bar_len) { + dev_err(&pci_dev->dev, + "%s: bar shorter than cap offset+len\n", + __func__); + return false; + } + + region->len = len; + region->addr = (u64) phys_addr + offset; + + return true; +} + static const struct virtio_config_ops virtio_pci_config_nodev_ops = { .get = NULL, .set = NULL, @@ -460,6 +566,7 @@ static const struct virtio_config_ops virtio_pci_config_nodev_ops = { .bus_name = vp_bus_name, .set_vq_affinity = vp_set_vq_affinity, .get_vq_affinity = vp_get_vq_affinity, + .get_shm_region = vp_get_shm_region, }; static const struct virtio_config_ops virtio_pci_config_ops = { @@ -476,6 +583,7 @@ static const struct virtio_config_ops virtio_pci_config_ops = { .bus_name = vp_bus_name, .set_vq_affinity = vp_set_vq_affinity, .get_vq_affinity = vp_get_vq_affinity, + .get_shm_region = vp_get_shm_region, }; /** diff --git a/include/uapi/linux/virtio_pci.h b/include/uapi/linux/virtio_pci.h index 90007a1abcab..31841a60a4ad 100644 --- a/include/uapi/linux/virtio_pci.h +++ b/include/uapi/linux/virtio_pci.h @@ -113,6 +113,8 @@ #define VIRTIO_PCI_CAP_DEVICE_CFG 4 /* PCI configuration access */ #define VIRTIO_PCI_CAP_PCI_CFG 5 +/* Additional shared memory capability */ +#define VIRTIO_PCI_CAP_SHARED_MEMORY_CFG 8 /* This is the PCI capability header: */ struct virtio_pci_cap { @@ -163,6 +165,14 @@ struct virtio_pci_cfg_cap { __u8 pci_cfg_data[4]; /* Data for BAR access. */ }; +/* Fields in VIRTIO_PCI_CAP_SHARED_MEMORY_CFG */ +struct virtio_pci_shm_cap { + struct virtio_pci_cap cap; + __le32 offset_hi; /* Most sig 32 bits of offset */ + __le32 length_hi; /* Most sig 32 bits of length */ + __u8 id; /* To distinguish shm chunks */ +}; + /* Macro versions of offsets for the Old Timers! */ #define VIRTIO_PCI_CAP_VNDR 0 #define VIRTIO_PCI_CAP_NEXT 1