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From: Thanos Makatos <thanos.makatos@nutanix.com>
To: "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>
Cc: Alex Williamson <alex.williamson@redhat.com>,
	Felipe Franciosi <felipe@nutanix.com>
Subject: question about handling MSI-X by VFIO
Date: Tue, 21 Jan 2020 13:36:26 +0000	[thread overview]
Message-ID: <MN2PR02MB6205CD9F680E4E7AEA7E5E518B0D0@MN2PR02MB6205.namprd02.prod.outlook.com> (raw)

I'm passing through a virtual PCI device to a QEMU guest via VFIO/mdev and I
notice that MSI-X interrupts are disabled in the device (MSIXCAP.MXC.MXE is
zero) and the BARs containing the table and PBA (4 and 5 in my case) are never
accessed.  However, whenever I fire an MSI-X interrupt from the virtual device
(although I'm not supposed to do so as they're disabled), the guest seems to
correctly receive it. I've started looking at hw/vfio/pci.c and it seems that
VFIO handles MSI-X interrupts there, including masking etc?


             reply	other threads:[~2020-01-21 14:23 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-21 13:36 Thanos Makatos [this message]
2020-01-21 17:19 ` question about handling MSI-X by VFIO Alex Williamson
2020-01-23 15:01   ` Thanos Makatos

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