[PATCH v2 1/4] conf: add xen specific feature: e820_host

Jim Fehlig jfehlig at suse.com
Tue Apr 14 22:05:21 UTC 2020

On 4/13/20 8:37 PM, Marek Marczykowski-Górecki wrote:
> e820_host is a Xen-specific option, only available for PV domains, that
> provides the domain a virtual e820 memory map based on the host one. It
> is required when using PCI passthrough and is generally considered safe
> for any PV kernel. e820_host is silently ignored if set in HVM domain
> configuration. See xl.cfg(5) man page in the Xen documentation for more
> details.
> Signed-off-by: Marek Marczykowski-Górecki <marmarek at invisiblethingslab.com>

This looks good to me now so

Reviewed-by: Jim Fehlig <jfehlig at suse.com>

But before pushing I'd like to settle on mapping the new 'passthrough' xl.cfg 
option to libvirt. See 

On xen 4.13 it seems 'passthrough' is enough for PV domains. Enabling it, and 
not e820_host, allows me to successfully hotplug a PCI device after PV domain 
creation. I haven't checked but I assume e820_host was needed to hotplug PCI 
devices with xen < 4.13?


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