From mboxrd@z Thu Jan 1 00:00:00 1970 From: Willem de Bruijn Subject: [PATCH RFC 2/2] virtio_net: enable probing for NEEDS_RESET support Date: Tue, 29 Aug 2017 16:07:59 -0400 Message-ID: <20170829200759.13975-3-willemdebruijn.kernel@gmail.com> References: <20170829200759.13975-1-willemdebruijn.kernel@gmail.com> Cc: mst@redhat.com, jasowang@redhat.com, virtualization@lists.linux-foundation.org, Willem de Bruijn To: netdev@vger.kernel.org Return-path: Received: from mail-qt0-f193.google.com ([209.85.216.193]:38143 "EHLO mail-qt0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751237AbdH2UIE (ORCPT ); Tue, 29 Aug 2017 16:08:04 -0400 Received: by mail-qt0-f193.google.com with SMTP id d15so3681248qta.5 for ; Tue, 29 Aug 2017 13:08:04 -0700 (PDT) In-Reply-To: <20170829200759.13975-1-willemdebruijn.kernel@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Willem de Bruijn Implement a mechanism to signal that a virtio device implements the VIRTIO_CONFIG_S_NEEDS_RESET command. Testing for VIRTIO_CONFIG_S_NEEDS_RESET support by issuing the request and verifying the reset state would require an expensive state change. To avoid that, add a status bit to the feature register used during feature negotiation between host and guest. Set the bit for virtio-net, which supports the feature. Signed-off-by: Willem de Bruijn --- drivers/net/virtio_net.c | 2 ++ include/uapi/linux/virtio_config.h | 3 +++ 2 files changed, 5 insertions(+) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 5e349226f7c1..15483a982106 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -2801,12 +2801,14 @@ static struct virtio_device_id id_table[] = { static unsigned int features[] = { VIRTNET_FEATURES, + VIRTIO_F_CAN_RESET, }; static unsigned int features_legacy[] = { VIRTNET_FEATURES, VIRTIO_NET_F_GSO, VIRTIO_F_ANY_LAYOUT, + VIRTIO_F_CAN_RESET, }; static struct virtio_driver virtio_net_driver = { diff --git a/include/uapi/linux/virtio_config.h b/include/uapi/linux/virtio_config.h index 308e2096291f..726be44a04d3 100644 --- a/include/uapi/linux/virtio_config.h +++ b/include/uapi/linux/virtio_config.h @@ -56,6 +56,9 @@ * suppressed them? */ #define VIRTIO_F_NOTIFY_ON_EMPTY 24 +/* Driver supports the VIRTIO_CONFIG_S_NEEDS_RESET command */ +#define VIRTIO_F_CAN_RESET 25 + /* Can the device handle any descriptor layout? */ #define VIRTIO_F_ANY_LAYOUT 27 #endif /* VIRTIO_CONFIG_NO_LEGACY */ -- 2.14.1.342.g6490525c54-goog