From nobody Sat Dec 27 13:05:45 2025 Received: from mail-yb1-f201.google.com (mail-yb1-f201.google.com [209.85.219.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B6DE7C12A for ; Tue, 19 Dec 2023 07:19:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--changyuanl.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="MtnxsFxB" Received: by mail-yb1-f201.google.com with SMTP id 3f1490d57ef6-daee86e2d70so3469788276.0 for ; Mon, 18 Dec 2023 23:19:49 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1702970389; x=1703575189; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=gZWYP/oOlOggqgKUebMmGuOo7PQ5M/AycpxW1yV0m6w=; b=MtnxsFxBxZNMGn2Luk18C1b1mf5zI3r0YaWQw9uHwRaq/Cg00HujuZWDf0nxuN5bcV tRXKw/ceP9i3ZeH+t8k2NfaapZcud6tyTwtKVrfwMiv3McJRIGPEqmTeb0RY4uMvmYTV 3XZYeaXQ9FOVhqxtuBlxWHFRM6PeoWPLtSMS07ztCn6Jd3Hneq6vBMmLR/p4PpNphtBw SS/n+e84Hmk+T0f05lUVaR6ny2UXZLu45Rdbdt3J9pdnQQORTtod5a7duNmnXg8tRwDG gl4MnKGNsns+tLywAgXmE/PbWp0h/lzAfboa6jpt1TmJLC/tUMtTbD9G1e8UqNHDHzfM 9Akw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1702970389; x=1703575189; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=gZWYP/oOlOggqgKUebMmGuOo7PQ5M/AycpxW1yV0m6w=; b=nO4quTxudqqSK7N5hwuK1aAnbdkZbxnaL3gbFiS8SOMyDZHJsVT2VbS8QPJuMZvDfH 9cU9yUUWiEQIc/B1gcW8dSlRb7+G9tvgvSAM1cAksuK3rcJ0iSuDO0XWsNWlVANiFp0c EGUBvY5J8zuZRYJMJnZw0wTg06l+fZsPMpB6x+Nw5l7lU+Fc3iKlURqreV3sk88cYjkR lDsgxvvuQbwtsKYpFlcVcoouXTsax4VC7+bbuJSz2IVGCw2+OGNM/v/GetuNIcnFkQxE Fyd321IawExRs02xXz3ic4eOGk9dUZvu2b71I4aSkJF0Wtg/BlSUd09J6evuZNHGBxXE fBjg== X-Gm-Message-State: AOJu0Yy/jblwl27wy3oARWZoXXRMHVoUjeV7r/0VkLl47M2yHPXy3ojp Rvkn72muk7cWP2JzBd81+7WNdZ/0cCwKaLXk X-Google-Smtp-Source: AGHT+IE+rN4NVhqEMOpU1c0Y1JbYbMaraxu/g+XW3gohe7Z0gme65cSYEjDzpnlNRx8dnz8oXjI74er4NvKN5KMi X-Received: from changyuanl-desktop.svl.corp.google.com ([2620:15c:2a3:200:b586:7ce5:ab58:992c]) (user=changyuanl job=sendgmr) by 2002:a25:b904:0:b0:db4:5e66:4a05 with SMTP id x4-20020a25b904000000b00db45e664a05mr324670ybj.2.1702970388799; Mon, 18 Dec 2023 23:19:48 -0800 (PST) Date: Mon, 18 Dec 2023 23:18:49 -0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.43.0.472.g3155946c3a-goog Message-ID: <20231219071849.3912896-1-changyuanl@google.com> Subject: [PATCH] virtio_pmem: support feature SHMEM_REGION From: Changyuan Lyu To: Pankaj Gupta , "Michael S . Tsirkin" , Jason Wang Cc: Xuan Zhuo , Dan Williams , Vishal Verma , Dave Jiang , virtualization@lists.linux.dev, nvdimm@lists.linux.dev, linux-kernel@vger.kernel.org, Changyuan Lyu Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" As per virtio spec 1.2 section 5.19.5.2, if the feature VIRTIO_PMEM_F_SHMEM_REGION has been negotiated, the driver MUST query shared memory ID 0 for the physical address ranges. Signed-off-by: Changyuan Lyu --- drivers/nvdimm/virtio_pmem.c | 29 +++++++++++++++++++++++++---- include/uapi/linux/virtio_pmem.h | 8 ++++++++ 2 files changed, 33 insertions(+), 4 deletions(-) diff --git a/drivers/nvdimm/virtio_pmem.c b/drivers/nvdimm/virtio_pmem.c index a92eb172f0e7..5b28d543728b 100644 --- a/drivers/nvdimm/virtio_pmem.c +++ b/drivers/nvdimm/virtio_pmem.c @@ -35,6 +35,8 @@ static int virtio_pmem_probe(struct virtio_device *vdev) struct nd_region *nd_region; struct virtio_pmem *vpmem; struct resource res; + struct virtio_shm_region shm_reg; + bool have_shm; int err =3D 0; =20 if (!vdev->config->get) { @@ -57,10 +59,23 @@ static int virtio_pmem_probe(struct virtio_device *vdev) goto out_err; } =20 - virtio_cread_le(vpmem->vdev, struct virtio_pmem_config, - start, &vpmem->start); - virtio_cread_le(vpmem->vdev, struct virtio_pmem_config, - size, &vpmem->size); + if (virtio_has_feature(vdev, VIRTIO_PMEM_F_SHMEM_REGION)) { + have_shm =3D virtio_get_shm_region(vdev, &shm_reg, + (u8)VIRTIO_PMEM_SHMCAP_ID); + if (!have_shm) { + dev_err(&vdev->dev, "failed to get shared memory region %d\n", + VIRTIO_PMEM_SHMCAP_ID); + return -EINVAL; + } + vpmem->start =3D shm_reg.addr; + vpmem->size =3D shm_reg.len; + } else { + virtio_cread_le(vpmem->vdev, struct virtio_pmem_config, + start, &vpmem->start); + virtio_cread_le(vpmem->vdev, struct virtio_pmem_config, + size, &vpmem->size); + } + =20 res.start =3D vpmem->start; res.end =3D vpmem->start + vpmem->size - 1; @@ -122,7 +137,13 @@ static void virtio_pmem_remove(struct virtio_device *v= dev) virtio_reset_device(vdev); } =20 +static unsigned int features[] =3D { + VIRTIO_PMEM_F_SHMEM_REGION, +}; + static struct virtio_driver virtio_pmem_driver =3D { + .feature_table =3D features, + .feature_table_size =3D ARRAY_SIZE(features), .driver.name =3D KBUILD_MODNAME, .driver.owner =3D THIS_MODULE, .id_table =3D id_table, diff --git a/include/uapi/linux/virtio_pmem.h b/include/uapi/linux/virtio_p= mem.h index d676b3620383..025174f6eacf 100644 --- a/include/uapi/linux/virtio_pmem.h +++ b/include/uapi/linux/virtio_pmem.h @@ -14,6 +14,14 @@ #include #include =20 +/* Feature bits */ +#define VIRTIO_PMEM_F_SHMEM_REGION 0 /* guest physical address range will = be + * indicated as shared memory region 0 + */ + +/* shmid of the shared memory region corresponding to the pmem */ +#define VIRTIO_PMEM_SHMCAP_ID 0 + struct virtio_pmem_config { __le64 start; __le64 size; --=20 2.43.0.472.g3155946c3a-goog