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From: alex.nlnnfn@proton.me
To: "xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>
Subject: memory overcomittment with sr-iov device assighment
Date: Tue, 07 Jun 2022 03:59:52 +0000	[thread overview]
Message-ID: <6f_bjKs323m5sDcqqvk3uosOLiugoCHlAvJ_tEMTl9d_05VqR-nOKtBBS4QWK29iKmorefG54vrbEgUM40Fl71BPZ0hwVyY3P0LjjJVjO-c=@proton.me> (raw)

Hello list,

I looked into Xen documentation and also Xen wiki and I could't find a definitive answer if Xen supports memory over-commitment when VMs use SR-IOV device assignment (passthrough). Memory over-commitment I mean giving VMs more RAM than is available in the host.

I know that ESX doesn't support it, and also QEMU/KVM pins all RAM when a device is directly assigned to a VM (VFIO_IOMMU_MAP_DMA ioctl). I have two questions:

1. Does Xen supports memory over commitment when all VMs are using direct device assignment e.g., SR-IOV?
2. Would you please point me to the code that does the pinning?

Thanks,
Alex





             reply	other threads:[~2022-06-07  4:38 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-06-07  3:59 alex.nlnnfn [this message]
2022-06-07  7:11 ` memory overcomittment with sr-iov device assighment Jan Beulich
2022-06-07 10:04 ` Andrew Cooper
2022-06-07 19:22   ` Alex Nln
2022-06-07 19:47     ` Andrew Cooper

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