From nobody Mon Feb 9 13:58:39 2026 Received: from sender4-pp-f112.zoho.com (sender4-pp-f112.zoho.com [136.143.188.112]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 437FF2D7DD3 for ; Thu, 25 Dec 2025 04:30:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=pass smtp.client-ip=136.143.188.112 ARC-Seal: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766637012; cv=pass; b=imjGUfH+0achW2EPdz7PqZbpjIyrssvPeTQGRQUpPL/yfjbObsjTbLdHNgTEI5bO9mQze6XA0w73WlQOvYeHd6cg/78aD0PdyhHP5KQIqdLTtdW1bIB6pfKgXOagPQbk/u/IcUGmqhWtIZgPn4jKU1uSm2DlI3lixKqCojO4YIA= ARC-Message-Signature: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766637012; c=relaxed/simple; bh=NKvd/+tYecCEMrXxwsKIas9vAt6h21VhWvobet9on7w=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=e/DZUGwLpLYzmWbWNBj22z6aY/qP0ly4DRc/jP9UhRj8w0VlwCpUwPoCZxCZI2TMZ3UDtVLfIeP6ggMZznEYID1Nj4Q5EnVG1ykPPX1vpK5RTddYARA6eEajNxNF7gozz/ZaoYHRd6tcDs1XYpv1yk2WQ3J9vH16alf51U+1/fg= ARC-Authentication-Results: i=2; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=linux.beauty; spf=pass smtp.mailfrom=linux.beauty; dkim=pass (1024-bit key) header.d=linux.beauty header.i=me@linux.beauty header.b=tI4f+PHX; arc=pass smtp.client-ip=136.143.188.112 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=linux.beauty Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.beauty Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.beauty header.i=me@linux.beauty header.b="tI4f+PHX" ARC-Seal: i=1; a=rsa-sha256; t=1766636978; cv=none; d=zohomail.com; s=zohoarc; b=mj/658IHAciprjVc8eFLBFi/mWEl/Ax6XC0jLmgGtazLG5NbbVJI5YVKtPlVcbTHH58sv16sDJzYS08xC8s7NZwpY/oij0RQC6QUPrUQXPmMsamW0od36fmj/46AviInCSzr6IH4FuilTvt4r/QiW3dDuWcSoRKhoE2Ay8assIw= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1766636978; h=Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:MIME-Version:Message-ID:References:Subject:Subject:To:To:Message-Id:Reply-To; bh=kJF4gdUrN1RWIspzsiP0AMfYxj80Tonv1/R4T+fQ7FQ=; b=RZZlCOaCo3d31wFP+8nhe3UeX9qVBe67nUb1mz8U/3DbSCuHuTs+UlHGBX8WrsiTL47vd/qo2HuStuNz2u71c7/mfa7fWAg0tOK/zPXZd98hIQIJ0epap3GExp2MLkQ5ghNavQVmE7rFuzjnb70Z/xeRlKY9ud1FJZi2U9p55N0= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass header.i=linux.beauty; spf=pass smtp.mailfrom=me@linux.beauty; dmarc=pass header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1766636978; s=zmail; d=linux.beauty; i=me@linux.beauty; h=From:From:To:To:Cc:Cc:Subject:Subject:Date:Date:Message-ID:In-Reply-To:References:MIME-Version:Content-Transfer-Encoding:Message-Id:Reply-To; bh=kJF4gdUrN1RWIspzsiP0AMfYxj80Tonv1/R4T+fQ7FQ=; b=tI4f+PHXbw4EXh1juDoLwlv/oQZiDFrKQJuP69hPcJunYDXWfqfWTNAKaHhLflZ5 B7/KQJRs1nWjYfF3ZCMEHTlzK7/cwvHa+wEGTksfvimLUITcUVUi8/feU7OVhTwDkqZ DbbPezdkKEYj1oUnT8mykXL4Z/WimzDu7KwCghDk= Received: by mx.zohomail.com with SMTPS id 1766636977078588.3208836388319; Wed, 24 Dec 2025 20:29:37 -0800 (PST) From: Li Chen To: Pankaj Gupta , Dan Williams , Vishal Verma , Dave Jiang , Ira Weiny , virtualization@lists.linux.dev, nvdimm@lists.linux.dev, linux-kernel@vger.kernel.org Cc: Li Chen Subject: [PATCH V2 3/5] nvdimm: virtio_pmem: converge broken virtqueue to -EIO Date: Thu, 25 Dec 2025 12:29:11 +0800 Message-ID: <20251225042915.334117-4-me@linux.beauty> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20251225042915.334117-1-me@linux.beauty> References: <20251225042915.334117-1-me@linux.beauty> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ZohoMailClient: External Content-Type: text/plain; charset="utf-8" virtio_pmem_flush() waits for either a free virtqueue descriptor (-ENOSPC) or a host completion. If the request virtqueue becomes broken (e.g. virtqueue_kick() notify failure), those waiters may never make progress. Track a device-level broken state and converge all error paths to -EIO. Fail fast for new requests, wake all -ENOSPC waiters, and drain/detach outstanding request tokens to complete them with an error. Signed-off-by: Li Chen --- drivers/nvdimm/nd_virtio.c | 73 +++++++++++++++++++++++++++++++++--- drivers/nvdimm/virtio_pmem.c | 7 ++++ drivers/nvdimm/virtio_pmem.h | 4 ++ 3 files changed, 78 insertions(+), 6 deletions(-) diff --git a/drivers/nvdimm/nd_virtio.c b/drivers/nvdimm/nd_virtio.c index d0385d4646f2..de1e3dde85eb 100644 --- a/drivers/nvdimm/nd_virtio.c +++ b/drivers/nvdimm/nd_virtio.c @@ -17,6 +17,18 @@ static void virtio_pmem_req_release(struct kref *kref) kfree(req); } =20 +static void virtio_pmem_signal_done(struct virtio_pmem_request *req) +{ + WRITE_ONCE(req->done, true); + wake_up(&req->host_acked); +} + +static void virtio_pmem_complete_err(struct virtio_pmem_request *req) +{ + req->resp.ret =3D cpu_to_le32(1); + virtio_pmem_signal_done(req); +} + static void virtio_pmem_wake_one_waiter(struct virtio_pmem *vpmem) { struct virtio_pmem_request *req_buf; @@ -31,6 +43,40 @@ static void virtio_pmem_wake_one_waiter(struct virtio_pm= em *vpmem) wake_up(&req_buf->wq_buf); } =20 +static void virtio_pmem_wake_all_waiters(struct virtio_pmem *vpmem) +{ + struct virtio_pmem_request *req, *tmp; + + list_for_each_entry_safe(req, tmp, &vpmem->req_list, list) { + WRITE_ONCE(req->wq_buf_avail, true); + wake_up(&req->wq_buf); + list_del_init(&req->list); + } +} + +void virtio_pmem_mark_broken_and_drain(struct virtio_pmem *vpmem) +{ + struct virtio_pmem_request *req; + unsigned int len; + + if (READ_ONCE(vpmem->broken)) + return; + + WRITE_ONCE(vpmem->broken, true); + dev_err_once(&vpmem->vdev->dev, "virtqueue is broken\n"); + virtio_pmem_wake_all_waiters(vpmem); + + while ((req =3D virtqueue_get_buf(vpmem->req_vq, &len)) !=3D NULL) { + virtio_pmem_complete_err(req); + kref_put(&req->kref, virtio_pmem_req_release); + } + + while ((req =3D virtqueue_detach_unused_buf(vpmem->req_vq)) !=3D NULL) { + virtio_pmem_complete_err(req); + kref_put(&req->kref, virtio_pmem_req_release); + } +} + /* The interrupt handler */ void virtio_pmem_host_ack(struct virtqueue *vq) { @@ -42,8 +88,7 @@ void virtio_pmem_host_ack(struct virtqueue *vq) spin_lock_irqsave(&vpmem->pmem_lock, flags); while ((req_data =3D virtqueue_get_buf(vq, &len)) !=3D NULL) { virtio_pmem_wake_one_waiter(vpmem); - WRITE_ONCE(req_data->done, true); - wake_up(&req_data->host_acked); + virtio_pmem_signal_done(req_data); kref_put(&req_data->kref, virtio_pmem_req_release); } spin_unlock_irqrestore(&vpmem->pmem_lock, flags); @@ -69,6 +114,9 @@ static int virtio_pmem_flush(struct nd_region *nd_region) return -EIO; } =20 + if (READ_ONCE(vpmem->broken)) + return -EIO; + might_sleep(); req_data =3D kmalloc(sizeof(*req_data), GFP_KERNEL); if (!req_data) @@ -114,22 +162,35 @@ static int virtio_pmem_flush(struct nd_region *nd_reg= ion) spin_unlock_irqrestore(&vpmem->pmem_lock, flags); =20 /* A host response results in "host_ack" getting called */ - wait_event(req_data->wq_buf, READ_ONCE(req_data->wq_buf_avail)); + wait_event(req_data->wq_buf, READ_ONCE(req_data->wq_buf_avail) || + READ_ONCE(vpmem->broken)); spin_lock_irqsave(&vpmem->pmem_lock, flags); + + if (READ_ONCE(vpmem->broken)) + break; } =20 - err1 =3D virtqueue_kick(vpmem->req_vq); + if (err =3D=3D -EIO || virtqueue_is_broken(vpmem->req_vq)) + virtio_pmem_mark_broken_and_drain(vpmem); + + err1 =3D true; + if (!err && !READ_ONCE(vpmem->broken)) { + err1 =3D virtqueue_kick(vpmem->req_vq); + if (!err1) + virtio_pmem_mark_broken_and_drain(vpmem); + } spin_unlock_irqrestore(&vpmem->pmem_lock, flags); /* * virtqueue_add_sgs failed with error different than -ENOSPC, we can't * do anything about that. */ - if (err || !err1) { + if (READ_ONCE(vpmem->broken) || err || !err1) { dev_info(&vdev->dev, "failed to send command to virtio pmem device\n"); err =3D -EIO; } else { /* A host response results in "host_ack" getting called */ - wait_event(req_data->host_acked, READ_ONCE(req_data->done)); + wait_event(req_data->host_acked, READ_ONCE(req_data->done) || + READ_ONCE(vpmem->broken)); err =3D le32_to_cpu(req_data->resp.ret); } =20 diff --git a/drivers/nvdimm/virtio_pmem.c b/drivers/nvdimm/virtio_pmem.c index 2396d19ce549..aa07328e3ff9 100644 --- a/drivers/nvdimm/virtio_pmem.c +++ b/drivers/nvdimm/virtio_pmem.c @@ -25,6 +25,7 @@ static int init_vq(struct virtio_pmem *vpmem) =20 spin_lock_init(&vpmem->pmem_lock); INIT_LIST_HEAD(&vpmem->req_list); + WRITE_ONCE(vpmem->broken, false); =20 return 0; }; @@ -137,6 +138,12 @@ static int virtio_pmem_probe(struct virtio_device *vde= v) static void virtio_pmem_remove(struct virtio_device *vdev) { struct nvdimm_bus *nvdimm_bus =3D dev_get_drvdata(&vdev->dev); + struct virtio_pmem *vpmem =3D vdev->priv; + unsigned long flags; + + spin_lock_irqsave(&vpmem->pmem_lock, flags); + virtio_pmem_mark_broken_and_drain(vpmem); + spin_unlock_irqrestore(&vpmem->pmem_lock, flags); =20 nvdimm_bus_unregister(nvdimm_bus); vdev->config->del_vqs(vdev); diff --git a/drivers/nvdimm/virtio_pmem.h b/drivers/nvdimm/virtio_pmem.h index fc8f613f8f28..49dd2e62d198 100644 --- a/drivers/nvdimm/virtio_pmem.h +++ b/drivers/nvdimm/virtio_pmem.h @@ -44,6 +44,9 @@ struct virtio_pmem { /* List to store deferred work if virtqueue is full */ struct list_head req_list; =20 + /* Fail fast and wake waiters if the request virtqueue is broken. */ + bool broken; + /* Synchronize virtqueue data */ spinlock_t pmem_lock; =20 @@ -53,5 +56,6 @@ struct virtio_pmem { }; =20 void virtio_pmem_host_ack(struct virtqueue *vq); +void virtio_pmem_mark_broken_and_drain(struct virtio_pmem *vpmem); int async_pmem_flush(struct nd_region *nd_region, struct bio *bio); #endif --=20 2.52.0