From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:40865 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728371AbeLJRNf (ORCPT ); Mon, 10 Dec 2018 12:13:35 -0500 From: Vivek Goyal To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: vgoyal@redhat.com, miklos@szeredi.hu, stefanha@redhat.com, dgilbert@redhat.com, sweil@redhat.com, swhiteho@redhat.com Subject: [PATCH 16/52] virtio-fs: Add VIRTIO_PCI_CAP_SHARED_MEMORY_CFG and utility to find them Date: Mon, 10 Dec 2018 12:12:42 -0500 Message-Id: <20181210171318.16998-17-vgoyal@redhat.com> In-Reply-To: <20181210171318.16998-1-vgoyal@redhat.com> References: <20181210171318.16998-1-vgoyal@redhat.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: From: "Dr. David Alan Gilbert" The shm cap defines a capability to allow 64bit size chunks at 64 bit size offsets into a bar. There can be multiple such chunks on any one device. Signed-off-by: Dr. David Alan Gilbert --- fs/fuse/virtio_fs.c | 69 +++++++++++++++++++++++++++++++++++++++++ include/uapi/linux/virtio_pci.h | 10 ++++++ 2 files changed, 79 insertions(+) diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c index 87b7e42a6763..cd916943205e 100644 --- a/fs/fuse/virtio_fs.c +++ b/fs/fuse/virtio_fs.c @@ -11,6 +11,7 @@ #include #include #include +#include #include "fuse_i.h" enum { @@ -57,6 +58,74 @@ struct virtio_fs { size_t window_len; }; +/* TODO: This should be in a PCI file somewhere */ +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 inline struct virtio_fs_vq *vq_to_fsvq(struct virtqueue *vq) { struct virtio_fs *fs = vq->vdev->priv; diff --git a/include/uapi/linux/virtio_pci.h b/include/uapi/linux/virtio_pci.h index 90007a1abcab..2e6072b5a7c9 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 -- 2.13.6