From: Rusty Russell <rusty@rustcorp.com.au>
To: "Michael S. Tsirkin" <mst@redhat.com>, linux-kernel@vger.kernel.org
Cc: virtualization@lists.linux-foundation.org
Subject: Re: [PATCH 6/6] virtio: core support for config generation
Date: Fri, 19 Dec 2014 13:31:53 +1030 [thread overview]
Message-ID: <87mw6ks5pa.fsf@rustcorp.com.au> (raw)
In-Reply-To: <1418678575-31755-7-git-send-email-mst@redhat.com>
"Michael S. Tsirkin" <mst@redhat.com> writes:
> virtio 1.0 spec says:
>
> Drivers MUST NOT assume reads from fields greater than 32 bits wide are
> atomic, nor are reads from multiple fields: drivers SHOULD read device
> configuration space fields like so:
> u32 before, after;
> do {
> before = get_config_generation(device);
> // read config entry/entries.
> after = get_config_generation(device);
> } while (after != before);
>
> Do exactly this, for transports that support it.
> static inline void virtio_cwrite8(struct virtio_device *vdev,
> @@ -352,6 +375,7 @@ static inline u64 virtio_cread64(struct virtio_device *vdev,
> {
> u64 ret;
> vdev->config->get(vdev, offset, &ret, sizeof(ret));
> + __virtio_cread_many(vdev, offset, &ret, 1, sizeof(ret));
> return virtio64_to_cpu(vdev, (__force __virtio64)ret);
> }
The "vdev->config->get(vdev, offset, &ret, sizeof(ret));" should
be deleted. Harmless if not, though.
Cheers,
Rusty.
prev parent reply other threads:[~2014-12-19 3:01 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-12-15 21:23 [PATCH 0/6] virtio 1.0 fixups, tweaks Michael S. Tsirkin
2014-12-15 21:23 ` [PATCH 1/6] virtio: set VIRTIO_CONFIG_S_FEATURES_OK on restore Michael S. Tsirkin
2014-12-15 21:23 ` [PATCH 2/6] virtio_config: fix virtio_cread_bytes Michael S. Tsirkin
2014-12-15 21:23 ` [PATCH 3/6] virtio_pci_common.h: drop VIRTIO_PCI_NO_LEGACY Michael S. Tsirkin
2014-12-15 21:23 ` [PATCH 4/6] virtio_pci: move probe to common file Michael S. Tsirkin
2014-12-15 21:23 ` [PATCH 5/6] virtio_pci: add VIRTIO_PCI_NO_LEGACY Michael S. Tsirkin
2014-12-15 21:23 ` [PATCH 6/6] virtio: core support for config generation Michael S. Tsirkin
2014-12-19 1:26 ` [PATCH 0/6] virtio 1.0 fixups, tweaks Rusty Russell
[not found] ` <1418678575-31755-7-git-send-email-mst@redhat.com>
2014-12-19 3:01 ` Rusty Russell [this message]
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