From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AB8JxZrhO/UnJcTL0RcZzlqWDHdwHoltRREXfESd4KFsgX6JDuxntGYkb7Qd97BU9XLZMRpIl1Qp ARC-Seal: i=1; a=rsa-sha256; t=1525116487; cv=none; d=google.com; s=arc-20160816; b=PVpt7IbWgBqRjJkJqeo0JSCPi9f8p9voJJQYOlfMcnZ0l2ikcj1ToUzIwis505L3TT KtkkFntn84YmK3kDG5uIupN+bVT7HopkLowWE1Cg9AiaMasw/clFB9/i2PElXEFb6JcB 9kkTxuXsr8SkHOlX22JprLULgoIVB3By3XZprmQLcW+FGTOokGCDMMXAh3dAwGSAmYtL y3QnCtjOCo+JFV1voERBV+11MLU5QOLsodXegA8+NMa+3w/o2K47JWzNnHaVSnQ81ezm 1QQFigYG589PgBgFdDJ03uzFTPNyrsrIfMA9jwOyLcoHlDwsTQ2wp+0pazH/gWlqBI0X WjdQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:dmarc-filter:arc-authentication-results; bh=tOgZcj4ZrDOy8Mxt5y2f9Yy4royyzsju31TyhcPFxMg=; b=yTMv+R7L+0hJzz013qLLis3Lsnw/8tohrHkszQcEfSqPTBeFa5SQoQDvubRSOSL5NS mD3uKsoHNzXJu0l7qDRXU40d1fMO8qMxDwkyeJ9BM7sW299u+iKFCG8l7sea5ntM856o UylL5RmQvj60cft1L63atxbRO2kr6HFL1YHRWH8VCV7H3E6/NR6cUroe4VMrvYLUWgnt v8CXDN5A8zITF44xg2v9bt0qNHFrgryod5oj2qRwScKZTSRlf9KSrcO4ZZRjoJVydDn8 rJDg6xBaqjYc99dBw0NXXlXSQzl+vezkhUQaZ2LWR47ur/elJevOsrrdhLhzpIE4d+Og AQAw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of srs0=k66p=ht=linuxfoundation.org=gregkh@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=SRS0=K66P=HT=linuxfoundation.org=gregkh@kernel.org Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of srs0=k66p=ht=linuxfoundation.org=gregkh@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=SRS0=K66P=HT=linuxfoundation.org=gregkh@kernel.org DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A4ADB22DC1 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=fail smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alain Magloire , Gerd Hoffmann , Dave Airlie , Sean Paul Subject: [PATCH 4.16 030/113] drm/virtio: fix vq wait_event condition Date: Mon, 30 Apr 2018 12:24:01 -0700 Message-Id: <20180430184016.343904638@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180430184015.043892819@linuxfoundation.org> References: <20180430184015.043892819@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1599200400304649329?= X-GMAIL-MSGID: =?utf-8?q?1599200545719744158?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Gerd Hoffmann commit d02d270014f70dcab0117776b81a37b6fca745ae upstream. Wait until we have enough space in the virt queue to actually queue up our request. Avoids the guest spinning in case we have a non-zero amount of free entries but not enough for the request. Cc: stable@vger.kernel.org Reported-by: Alain Magloire Signed-off-by: Gerd Hoffmann Reviewed-by: Dave Airlie Link: http://patchwork.freedesktop.org/patch/msgid/20180403095904.11152-1-kraxel@redhat.com Signed-off-by: Sean Paul Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/virtio/virtgpu_vq.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/gpu/drm/virtio/virtgpu_vq.c +++ b/drivers/gpu/drm/virtio/virtgpu_vq.c @@ -291,7 +291,7 @@ retry: ret = virtqueue_add_sgs(vq, sgs, outcnt, incnt, vbuf, GFP_ATOMIC); if (ret == -ENOSPC) { spin_unlock(&vgdev->ctrlq.qlock); - wait_event(vgdev->ctrlq.ack_queue, vq->num_free); + wait_event(vgdev->ctrlq.ack_queue, vq->num_free >= outcnt + incnt); spin_lock(&vgdev->ctrlq.qlock); goto retry; } else { @@ -366,7 +366,7 @@ retry: ret = virtqueue_add_sgs(vq, sgs, outcnt, 0, vbuf, GFP_ATOMIC); if (ret == -ENOSPC) { spin_unlock(&vgdev->cursorq.qlock); - wait_event(vgdev->cursorq.ack_queue, vq->num_free); + wait_event(vgdev->cursorq.ack_queue, vq->num_free >= outcnt); spin_lock(&vgdev->cursorq.qlock); goto retry; } else {