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From: Thanos Makatos <thanos.makatos@nutanix.com>
To: "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>
Cc: "alex.williamson@redhat.com" <alex.williamson@redhat.com>,
	Raphael Norwitz <raphael.norwitz@nutanix.com>
Subject: question regarding QEMU adding overlapping memory regions to VFIO
Date: Fri, 7 May 2021 13:51:52 +0000	[thread overview]
Message-ID: <MW2PR02MB3723B94416375A06F6F69BB08B579@MW2PR02MB3723.namprd02.prod.outlook.com> (raw)

I've noticed that QEMU adds overlapping memory regions to VFIO, e.g.:

vfio_listener_region_add_ram region_add [ram] 0xc0000 - 0xc0fff [0x7f6702c00000]
vfio_listener_region_del region_del 0xc4000 - 0xdffff
vfio_listener_region_add_ram region_add [ram] 0xc1000 - 0xc3fff [0x7f66406c1000]
vfio_listener_region_del region_del 0xe0000 - 0xfffff
vfio_listener_region_add_ram region_add [ram] 0xc4000 - 0xdffff [0x7f6702c04000]
vfio_listener_region_add_ram region_add [ram] 0xc0000 - 0xc0fff [0x7f66406c0000]
2021-05-05T09:38:16.158864Z qemu-system-x86_64: vfio_dma_map(0x557b8fd281b0, 0xc0000, 0x1000, 0x7f66406c0000) = -22 (Resource temporarily unavailable)

Region 0xc0000 - 0xc0fff is added first and then region 0xc0000 - 0xc0fff is added again? Is this legitimate? What is the implication of this? Is the previous region replaced by the more recent one?


             reply	other threads:[~2021-05-07 13:52 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-07 13:51 Thanos Makatos [this message]
2021-05-07 15:42 ` question regarding QEMU adding overlapping memory regions to VFIO Alex Williamson
2021-05-07 16:22   ` Thanos Makatos

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