From: "Jan Beulich" <JBeulich@suse.com>
To: Chao Gao <chao.gao@intel.com>
Cc: Juergen Gross <jgross@suse.com>,
Stefano Stabellini <sstabellini@kernel.org>,
linux-kernel@vger.kernel.org, Jia-Ju Bai <baijiaju1990@gmail.com>,
xen-devel <xen-devel@lists.xenproject.org>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
Roger Pau Monne <roger.pau@citrix.com>
Subject: Re: [PATCH] xen: xen-pciback: Reset MSI-X state when exposing a device
Date: Wed, 05 Dec 2018 09:26:32 -0700 [thread overview]
Message-ID: <5C07FC380200007800203394__45026.2645645582$1544027132$gmane$org@prv1-mh.provo.novell.com> (raw)
In-Reply-To: <1543976357-1053-1-git-send-email-chao.gao@intel.com>
>>> On 05.12.18 at 03:19, <chao.gao@intel.com> wrote:
> --- a/drivers/xen/xen-pciback/pci_stub.c
> +++ b/drivers/xen/xen-pciback/pci_stub.c
> @@ -87,6 +87,55 @@ static struct pcistub_device *pcistub_device_alloc(struct pci_dev *dev)
> return psdev;
> }
>
> +/*
> + * Reset Xen internal MSI-X state by invoking PHYSDEVOP_{release, prepare}_msix.
> + */
> +int pcistub_msix_reset(struct pci_dev *dev)
> +{
> +#ifdef CONFIG_PCI_MSI
> + if (dev->msix_cap) {
> + struct physdev_pci_device ppdev = {
> + .seg = pci_domain_nr(dev->bus),
> + .bus = dev->bus->number,
> + .devfn = dev->devfn
> + };
> + int err;
> + u16 val;
> +
> + /*
> + * Do a write first to flush Xen's internal state to hardware
> + * such that the following read can infer whether MSI-X maskall
> + * bit is set by Xen.
> + */
> + pci_read_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, &val);
> + pci_write_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, val);
> +
> + pci_read_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, &val);
> + if (!(val & PCI_MSIX_FLAGS_MASKALL))
> + return 0;
I'm agreeing with prior comments: I don't see why you need
this conditional.
> + pr_info("Reset MSI-X state for device %04x:%02x:%02x.%d\n",
> + ppdev.seg, ppdev.bus, PCI_SLOT(ppdev.devfn),
> + PCI_FUNC(ppdev.devfn));
> +
> + err = HYPERVISOR_physdev_op(PHYSDEVOP_release_msix, &ppdev);
> + if (err) {
> + dev_warn(&dev->dev, "MSI-X release failed (%d)\n",
> + err);
> + return err;
> + }
> +
> + err = HYPERVISOR_physdev_op(PHYSDEVOP_prepare_msix, &ppdev);
> + if (err) {
> + dev_err(&dev->dev, "MSI-X preparation failed (%d)\n",
> + err);
Please can you make both log messages distinguishable from
the pre-existing ones, to aid diagnosis of possible probelms?
Jan
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next prev parent reply other threads:[~2018-12-05 16:26 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1543976357-1053-1-git-send-email-chao.gao@intel.com>
2018-12-05 9:32 ` [PATCH] xen: xen-pciback: Reset MSI-X state when exposing a device Roger Pau Monné
2018-12-05 16:26 ` Jan Beulich [this message]
[not found] ` <20181205093223.dncg4nq4dh6xmrhk@mac>
2018-12-05 14:01 ` Boris Ostrovsky
2018-12-06 2:18 ` Chao Gao
[not found] ` <c27236d3-6125-4049-6268-3d9c93cf3ef2@oracle.com>
2018-12-12 7:06 ` Chao Gao
[not found] ` <20181212070654.GA13411@gao-cwp>
2018-12-12 8:51 ` Jan Beulich
[not found] ` <5C10CBF50200007800205596@prv1-mh.provo.novell.com>
2018-12-12 15:18 ` Chao Gao
[not found] ` <20181212151824.GA17227@gao-cwp>
2018-12-12 15:21 ` Jan Beulich
[not found] ` <5C112783020000780020589C@prv1-mh.provo.novell.com>
2018-12-13 3:46 ` Chao Gao
[not found] ` <20181213034657.GA26926@gao-cwp>
2018-12-13 7:54 ` Jan Beulich
[not found] ` <5C12104C0200007800205B4B@prv1-mh.provo.novell.com>
2018-12-13 13:17 ` Chao Gao
2019-09-13 10:02 ` [Xen-devel] " Spassov, Stanislav
2019-09-13 15:28 ` Chao Gao
2019-09-26 10:13 ` Pasi Kärkkäinen
2019-09-26 10:54 ` Spassov, Stanislav
2020-01-17 18:57 ` Rich Persaud
2020-01-18 1:13 ` Chao Gao
2018-12-05 2:19 Chao Gao
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