From patchwork Thu Mar 28 08:03:43 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xuan Zhuo X-Patchwork-Id: 13608122 Received: from out30-130.freemail.mail.aliyun.com (out30-130.freemail.mail.aliyun.com [115.124.30.130]) (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 4811B4EB44; Thu, 28 Mar 2024 08:03:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.130 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711613038; cv=none; b=jCDjSs52WuxLJIaImGOmrbXT46CNsgxWT8zxBPOlR04z82Ko+L+5Jcep9U6wXkf0Hjzdv0Sf9OeFQjleXKRfv9gusqdYugM6F4IftbckqrfzwJqUzYkKvOAHWHQspoCTdZDdsvKtctGjMkVarXBXDHGYuOdZ2f1P7lDv7vQIVs4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711613038; c=relaxed/simple; bh=pD0PHgRIr4QAD7ckc8UQSsbAKSahbn8SJvAjJkgT0gY=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=FGFpJoMwkC+MKvW4sGQXSiMRs5NcmE0ZS0EG4kZhzwoHZyOmCmulq74iDlcdDOWK0q2a20u9MCa22ZsmLtrfrkxIdP31aViCSfnfkY9U0uak4Kp0C0NK/vq31DLaArgoasUZsFSEHD6iE3EjfSvltLLKB8TbVv6mNhjUxfRacNs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=bU6lYi/5; arc=none smtp.client-ip=115.124.30.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="bU6lYi/5" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1711613033; h=From:To:Subject:Date:Message-Id:MIME-Version; bh=4mPU8uVU62Gx+L9YfY51VYVWJr6/PqFv0TCtZ2FCoKo=; b=bU6lYi/5rcb8Htfn/+K/QsGWgTStnGUVGt7SY5Azh66lD4rmaf46HkoPWva/kecfUafohsUSqfc+qos4bEJSAXOc1pIZouGyQs39i3aqFoefU6jwTb57UIpUhehp3rmy1dbrq5rGMd0Y7vmJIfwVthsNGEhILhoNPDzS6Gp09aU= X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R291e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046056;MF=xuanzhuo@linux.alibaba.com;NM=1;PH=DS;RN=26;SR=0;TI=SMTPD_---0W3Sg6GP_1711613030; Received: from localhost(mailfrom:xuanzhuo@linux.alibaba.com fp:SMTPD_---0W3Sg6GP_1711613030) by smtp.aliyun-inc.com; Thu, 28 Mar 2024 16:03:51 +0800 From: Xuan Zhuo To: virtualization@lists.linux.dev Cc: Richard Weinberger , Anton Ivanov , Johannes Berg , Hans de Goede , =?utf-8?q?Ilpo_J=C3=A4rvinen?= , Vadim Pasternak , Bjorn Andersson , Mathieu Poirier , Cornelia Huck , Halil Pasic , Eric Farman , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , "Michael S. Tsirkin" , David Hildenbrand , Jason Wang , Xuan Zhuo , linux-um@lists.infradead.org, platform-driver-x86@vger.kernel.org, linux-remoteproc@vger.kernel.org, linux-s390@vger.kernel.org, kvm@vger.kernel.org Subject: [PATCH vhost v7 1/6] virtio_balloon: remove the dependence where names[] is null Date: Thu, 28 Mar 2024 16:03:43 +0800 Message-Id: <20240328080348.3620-2-xuanzhuo@linux.alibaba.com> X-Mailer: git-send-email 2.32.0.3.g01195cf9f In-Reply-To: <20240328080348.3620-1-xuanzhuo@linux.alibaba.com> References: <20240328080348.3620-1-xuanzhuo@linux.alibaba.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Git-Hash: fc2c3bb8a235 Currently, the init_vqs function within the virtio_balloon driver relies on the condition that certain names array entries are null in order to skip the initialization of some virtual queues (vqs). This behavior is unique to this part of the codebase. In an upcoming commit, we plan to eliminate this dependency by removing the function entirely. Therefore, with this change, we are ensuring that the virtio_balloon no longer depends on the aforementioned function. As specification 1.0-1.2, vq indexes should not be contiguous if some vq does not exist. But currently the virtqueue index is contiguous for all existing devices. The Linux kernel does not implement functionality to allow vq indexes to be discontinuous. So the current behavior of the virtio-balloon device is different for the spec. But this commit has no functional changes. Signed-off-by: Xuan Zhuo Acked-by: David Hildenbrand Acked-by: Jason Wang --- drivers/virtio/virtio_balloon.c | 48 ++++++++++++++------------------- 1 file changed, 20 insertions(+), 28 deletions(-) diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index 1f5b3dd31fcf..f5ed351e31d4 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -531,49 +531,41 @@ static int init_vqs(struct virtio_balloon *vb) struct virtqueue *vqs[VIRTIO_BALLOON_VQ_MAX]; vq_callback_t *callbacks[VIRTIO_BALLOON_VQ_MAX]; const char *names[VIRTIO_BALLOON_VQ_MAX]; - int err; + int err, idx = 0; - /* - * Inflateq and deflateq are used unconditionally. The names[] - * will be NULL if the related feature is not enabled, which will - * cause no allocation for the corresponding virtqueue in find_vqs. - */ - callbacks[VIRTIO_BALLOON_VQ_INFLATE] = balloon_ack; - names[VIRTIO_BALLOON_VQ_INFLATE] = "inflate"; - callbacks[VIRTIO_BALLOON_VQ_DEFLATE] = balloon_ack; - names[VIRTIO_BALLOON_VQ_DEFLATE] = "deflate"; - callbacks[VIRTIO_BALLOON_VQ_STATS] = NULL; - names[VIRTIO_BALLOON_VQ_STATS] = NULL; - callbacks[VIRTIO_BALLOON_VQ_FREE_PAGE] = NULL; - names[VIRTIO_BALLOON_VQ_FREE_PAGE] = NULL; - names[VIRTIO_BALLOON_VQ_REPORTING] = NULL; + callbacks[idx] = balloon_ack; + names[idx++] = "inflate"; + callbacks[idx] = balloon_ack; + names[idx++] = "deflate"; if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_STATS_VQ)) { - names[VIRTIO_BALLOON_VQ_STATS] = "stats"; - callbacks[VIRTIO_BALLOON_VQ_STATS] = stats_request; + names[idx] = "stats"; + callbacks[idx++] = stats_request; } if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT)) { - names[VIRTIO_BALLOON_VQ_FREE_PAGE] = "free_page_vq"; - callbacks[VIRTIO_BALLOON_VQ_FREE_PAGE] = NULL; + names[idx] = "free_page_vq"; + callbacks[idx++] = NULL; } if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_REPORTING)) { - names[VIRTIO_BALLOON_VQ_REPORTING] = "reporting_vq"; - callbacks[VIRTIO_BALLOON_VQ_REPORTING] = balloon_ack; + names[idx] = "reporting_vq"; + callbacks[idx++] = balloon_ack; } - err = virtio_find_vqs(vb->vdev, VIRTIO_BALLOON_VQ_MAX, vqs, - callbacks, names, NULL); + err = virtio_find_vqs(vb->vdev, idx, vqs, callbacks, names, NULL); if (err) return err; - vb->inflate_vq = vqs[VIRTIO_BALLOON_VQ_INFLATE]; - vb->deflate_vq = vqs[VIRTIO_BALLOON_VQ_DEFLATE]; + idx = 0; + + vb->inflate_vq = vqs[idx++]; + vb->deflate_vq = vqs[idx++]; + if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_STATS_VQ)) { struct scatterlist sg; unsigned int num_stats; - vb->stats_vq = vqs[VIRTIO_BALLOON_VQ_STATS]; + vb->stats_vq = vqs[idx++]; /* * Prime this virtqueue with one buffer so the hypervisor can @@ -593,10 +585,10 @@ static int init_vqs(struct virtio_balloon *vb) } if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT)) - vb->free_page_vq = vqs[VIRTIO_BALLOON_VQ_FREE_PAGE]; + vb->free_page_vq = vqs[idx++]; if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_REPORTING)) - vb->reporting_vq = vqs[VIRTIO_BALLOON_VQ_REPORTING]; + vb->reporting_vq = vqs[idx++]; return 0; }