From: Stefan Hajnoczi <stefanha@gmail.com>
To: Pankaj Gupta <pagupta@redhat.com>
Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
qemu-devel@nongnu.org, linux-nvdimm@ml01.01.org,
linux-mm@kvack.org, jack@suse.cz, stefanha@redhat.com,
dan.j.williams@intel.com, riel@surriel.com,
haozhong.zhang@intel.com, nilal@redhat.com, kwolf@redhat.com,
pbonzini@redhat.com, ross.zwisler@intel.com, david@redhat.com,
xiaoguangrong.eric@gmail.com, hch@infradead.org,
marcel@redhat.com, mst@redhat.com, niteshnarayanlal@hotmail.com,
imammedo@redhat.com, lcapitulino@redhat.com
Subject: Re: [RFC v2] qemu: Add virtio pmem device
Date: Thu, 26 Apr 2018 14:24:06 +0100 [thread overview]
Message-ID: <20180426132406.GC30991@stefanha-x1.localdomain> (raw)
In-Reply-To: <20180425112415.12327-4-pagupta@redhat.com>
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On Wed, Apr 25, 2018 at 04:54:15PM +0530, Pankaj Gupta wrote:
> +static void virtio_pmem_flush(VirtIODevice *vdev, VirtQueue *vq)
> +{
> + VirtQueueElement *elem;
> + VirtIOPMEM *pmem = VIRTIO_PMEM(vdev);
> + HostMemoryBackend *backend = MEMORY_BACKEND(pmem->memdev);
> + int fd = memory_region_get_fd(&backend->mr);
> +
> + elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
> + if (!elem) {
> + return;
> + }
> + /* flush raw backing image */
> + fsync(fd);
fsync(2) is a blocking syscall. This can hang QEMU for an unbounded
amount of time.
Please do the fsync from a thread pool. See block/file-posix.c's
aio_worker() for an example.
> +static void virtio_pmem_get_config(VirtIODevice *vdev, uint8_t *config)
> +{
> + VirtIOPMEM *pmem = VIRTIO_PMEM(vdev);
> + struct virtio_pmem_config *pmemcfg = (struct virtio_pmem_config *) config;
> +
> + pmemcfg->start = pmem->start;
> + pmemcfg->size = pmem->size;
Endianness. Please use virtio_st*_p() instead.
> +#define VIRTIO_PMEM_PLUG 0
What is this?
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WARNING: multiple messages have this Message-ID (diff)
From: Stefan Hajnoczi <stefanha@gmail.com>
To: Pankaj Gupta <pagupta@redhat.com>
Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
qemu-devel@nongnu.org, linux-nvdimm@ml01.01.org,
linux-mm@kvack.org, jack@suse.cz, stefanha@redhat.com,
dan.j.williams@intel.com, riel@surriel.com,
haozhong.zhang@intel.com, nilal@redhat.com, kwolf@redhat.com,
pbonzini@redhat.com, ross.zwisler@intel.com, david@redhat.com,
xiaoguangrong.eric@gmail.com, hch@infradead.org,
marcel@redhat.com, mst@redhat.com, niteshnarayanlal@hotmail.com,
imammedo@redhat.com, lcapitulino@redhat.com
Subject: Re: [Qemu-devel] [RFC v2] qemu: Add virtio pmem device
Date: Thu, 26 Apr 2018 14:24:06 +0100 [thread overview]
Message-ID: <20180426132406.GC30991@stefanha-x1.localdomain> (raw)
In-Reply-To: <20180425112415.12327-4-pagupta@redhat.com>
[-- Attachment #1: Type: text/plain, Size: 1057 bytes --]
On Wed, Apr 25, 2018 at 04:54:15PM +0530, Pankaj Gupta wrote:
> +static void virtio_pmem_flush(VirtIODevice *vdev, VirtQueue *vq)
> +{
> + VirtQueueElement *elem;
> + VirtIOPMEM *pmem = VIRTIO_PMEM(vdev);
> + HostMemoryBackend *backend = MEMORY_BACKEND(pmem->memdev);
> + int fd = memory_region_get_fd(&backend->mr);
> +
> + elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
> + if (!elem) {
> + return;
> + }
> + /* flush raw backing image */
> + fsync(fd);
fsync(2) is a blocking syscall. This can hang QEMU for an unbounded
amount of time.
Please do the fsync from a thread pool. See block/file-posix.c's
aio_worker() for an example.
> +static void virtio_pmem_get_config(VirtIODevice *vdev, uint8_t *config)
> +{
> + VirtIOPMEM *pmem = VIRTIO_PMEM(vdev);
> + struct virtio_pmem_config *pmemcfg = (struct virtio_pmem_config *) config;
> +
> + pmemcfg->start = pmem->start;
> + pmemcfg->size = pmem->size;
Endianness. Please use virtio_st*_p() instead.
> +#define VIRTIO_PMEM_PLUG 0
What is this?
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next prev parent reply other threads:[~2018-04-26 13:24 UTC|newest]
Thread overview: 80+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-25 11:24 [RFC v2 0/2] kvm "fake DAX" device flushing Pankaj Gupta
2018-04-25 11:24 ` [Qemu-devel] " Pankaj Gupta
2018-04-25 11:24 ` Pankaj Gupta
[not found] ` <20180425112415.12327-1-pagupta-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2018-04-25 11:24 ` [RFC v2 1/2] virtio: add pmem driver Pankaj Gupta
2018-04-25 11:24 ` [Qemu-devel] " Pankaj Gupta
2018-04-25 11:24 ` Pankaj Gupta
[not found] ` <20180425112415.12327-2-pagupta-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2018-04-25 14:21 ` Dan Williams
2018-04-25 14:21 ` [Qemu-devel] " Dan Williams
2018-04-25 14:21 ` Dan Williams
[not found] ` <CAPcyv4hvrB08XPTbVK0xT2_1Xmaid=-v3OMxJVDTNwQucsOHLA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2018-04-25 14:43 ` Dan Williams
2018-04-25 14:43 ` [Qemu-devel] " Dan Williams
2018-04-25 14:43 ` Dan Williams
[not found] ` <CAPcyv4hiowWozV527sQA_e4fdgCYbD6xfG==vepAqu0hxQEQcw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2018-04-26 12:27 ` Jeff Moyer
2018-04-26 12:27 ` [Qemu-devel] " Jeff Moyer
2018-04-26 12:27 ` Jeff Moyer
2018-04-26 12:27 ` Jeff Moyer
[not found] ` <x49o9i6885e.fsf-RRHT56Q3PSP4kTEheFKJxxDDeQx5vsVwAInAS/Ez/D0@public.gmane.org>
2018-04-26 17:15 ` [Qemu-devel] " Pankaj Gupta
2018-04-26 17:15 ` Pankaj Gupta
[not found] ` <1499190564.23017177.1524762938762.JavaMail.zimbra-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2018-04-26 17:24 ` Jeff Moyer
2018-04-26 17:24 ` Jeff Moyer
2018-04-25 14:52 ` Michael S. Tsirkin
2018-04-25 14:52 ` [Qemu-devel] " Michael S. Tsirkin
2018-04-25 14:52 ` Michael S. Tsirkin
[not found] ` <20180425174705-mutt-send-email-mst-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
2018-04-25 15:11 ` [Qemu-devel] " Pankaj Gupta
2018-04-25 15:11 ` Pankaj Gupta
2018-04-26 13:12 ` Stefan Hajnoczi
[not found] ` <20180426131236.GA30991-lxVrvc10SDRcolVlb+j0YCZi+YwRKgec@public.gmane.org>
2018-04-26 15:44 ` Pankaj Gupta
2018-04-26 15:44 ` Pankaj Gupta
2018-04-27 13:31 ` Stefan Hajnoczi
[not found] ` <20180427133146.GB11150-lxVrvc10SDRcolVlb+j0YCZi+YwRKgec@public.gmane.org>
2018-04-28 10:48 ` Pankaj Gupta
2018-04-28 10:48 ` Pankaj Gupta
2018-04-25 11:24 ` [RFC v2 2/2] pmem: device flush over VIRTIO Pankaj Gupta
2018-04-25 11:24 ` [Qemu-devel] " Pankaj Gupta
2018-04-25 11:24 ` Pankaj Gupta
[not found] ` <20180425112415.12327-3-pagupta-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2018-04-25 14:23 ` Dan Williams
2018-04-25 14:23 ` [Qemu-devel] " Dan Williams
2018-04-25 14:23 ` Dan Williams
[not found] ` <CAPcyv4gpZzKfE7jY1peYOVd6sVhNz7jce1s_xNH_2Lt8AjRK-Q-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2018-04-25 14:47 ` Pankaj Gupta
2018-04-25 14:47 ` [Qemu-devel] " Pankaj Gupta
2018-04-25 14:47 ` Pankaj Gupta
2018-04-26 13:15 ` Stefan Hajnoczi
2018-04-26 13:15 ` [Qemu-devel] " Stefan Hajnoczi
[not found] ` <20180426131517.GB30991-lxVrvc10SDRcolVlb+j0YCZi+YwRKgec@public.gmane.org>
2018-04-26 16:40 ` Pankaj Gupta
2018-04-26 16:40 ` [Qemu-devel] " Pankaj Gupta
2018-04-26 16:40 ` Pankaj Gupta
[not found] ` <58645254.23011245.1524760853269.JavaMail.zimbra-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2018-04-26 16:57 ` Dan Williams
2018-04-26 16:57 ` [Qemu-devel] " Dan Williams
2018-04-26 16:57 ` Dan Williams
[not found] ` <CAPcyv4jv-hJNKJxak98T7aCnWztVEDTE8o=8fjvOrVmrTfyjdA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2018-04-26 17:13 ` Pankaj Gupta
2018-04-26 17:13 ` [Qemu-devel] " Pankaj Gupta
2018-04-26 17:13 ` Pankaj Gupta
2018-04-25 11:24 ` [RFC v2] qemu: Add virtio pmem device Pankaj Gupta
2018-04-25 11:24 ` [Qemu-devel] " Pankaj Gupta
2018-04-25 11:24 ` Pankaj Gupta
[not found] ` <20180425112415.12327-4-pagupta-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2018-04-25 11:35 ` [Qemu-devel] " no-reply-isE1Te71pDtAfugRpC6u6w
2018-04-25 11:35 ` no-reply
2018-04-25 11:35 ` no-reply
2018-04-25 11:58 ` Pankaj Gupta
2018-04-25 11:58 ` Pankaj Gupta
2018-04-25 14:23 ` Eric Blake
2018-04-25 14:23 ` Eric Blake
[not found] ` <79f72139-0fcb-3d5e-a16c-24f3b5ee1a07-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2018-04-25 14:51 ` Pankaj Gupta
2018-04-25 14:51 ` Pankaj Gupta
2018-04-25 11:46 ` no-reply
2018-04-25 11:46 ` no-reply
2018-04-25 11:46 ` no-reply
2018-04-25 14:25 ` Eric Blake
2018-04-25 14:25 ` Eric Blake
[not found] ` <25f3e433-cfa6-4a62-ba7f-47aef1119dfc-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2018-04-25 14:55 ` Pankaj Gupta
2018-04-25 14:55 ` Pankaj Gupta
2018-04-26 13:24 ` Stefan Hajnoczi [this message]
2018-04-26 13:24 ` Stefan Hajnoczi
[not found] ` <20180426132406.GC30991-lxVrvc10SDRcolVlb+j0YCZi+YwRKgec@public.gmane.org>
2018-04-26 16:43 ` Pankaj Gupta
2018-04-26 16:43 ` Pankaj Gupta
2018-06-01 12:24 ` [Qemu-devel] [RFC v2 0/2] kvm "fake DAX" device flushing Igor Mammedov
2018-06-01 12:24 ` Igor Mammedov
[not found] ` <20180601142410.5c986f13-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2018-06-04 5:56 ` Pankaj Gupta
2018-06-04 5:56 ` Pankaj Gupta
2018-06-04 9:55 ` David Hildenbrand
2018-06-04 9:55 ` David Hildenbrand
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