Thanks!

> -------- Original Message --------
> Subject: Re: [qubes-devel] qvm-block and qvm-usb implementation
> Local Time: 3 gennaio 2018 8:38 AM
> UTC Time: 3 gennaio 2018 07:38
> From: [email protected]
> To: Drolo <[email protected]>
> [email protected] <[email protected]>
>
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA256
>
> On Tue, Jan 02, 2018 at 02:40:16PM -0500, 'Drolo' via qubes-devel wrote:
>
>> Hi,
>> I'm interested in how qvm-block and qvm-usb are implemented and in which way 
>> they interact in the USB drive case. Here is what i discovered about PCI 
>> Passthrough and USB Passthrough:
>> From [0] I read that Qubes OS uses VT-d (through [3] and [5]) to isolate 
>> networking and USB controllers in domains. In fact lspci (in dom0) states 
>> that the pciback driver is associated with those PCI devices. So dom0 
>> handles only the passthru, nothing more.
>> [6] states that it's not possible to assign a single USB devices to a 
>> domain, because VT-d design. However I think that it's not updated because 
>> qubes-usb-proxy ([2]). From [7] and [8] I deduced that qvm-usb uses PVUSB 
>> ([4]) to passthru single USB device.
>> From [1] I read that qvm-block uses Xen block backed hosted in the UsbVM. 
>> Initially I didn't find what it refers to. Then I found xl block-attach 
>> command (from [2]). So I found [10] and [11].
>> So I concluded:
>>
>> - qvm-usb uses PVUSB. However Qubes OS's xl doesn't seems to implement 
>> usb-list and related.
>> - qvm-pci uses Xen PCI passthru. So xl pci-attach and related.
>> - Specifically for network: xl network-attach. From [2] I read that because 
>> [12] the attack surface is smaller in guest domain. So the security benefit.
>> - qvm-block uses xl block-attach and related.
>> - qvm-block is independent from qvm-usb, after that the guest domain detect 
>> the drive.
>>
>> Are these conclusions correct?
>
> Almost: qvm-usb uses USBIP over qrexec instead of IP. Some details are
> here:
> https://github.com/QubesOS/qubes-app-linux-usb-proxy
>
> Other points are correct.
>
>> [0] = 
>> https://www.qubes-os.org/attachment/wiki/QubesArchitecture/arch-spec-0.3.pdf
>> [1] = 
>> https://invisiblethingslab.com/resources/2014/Software_compartmentalization_vs_physical_separation.pdf
>> [2] = https://www.qubes-os.org/doc/usb/
>> [3] = https://wiki.xenproject.org/wiki/Xen_PCI_Passthrough
>> [4] = https://wiki.xenproject.org/wiki/Xen_USB_Passthrough
>> [5] = https://wiki.xenproject.org/wiki/Driver_Domain
>> [6] = https://www.qubes-os.org/doc/assigning-devices/
>> [7] = https://github.com/QubesOS/qubes-issues/issues/2144
>> [8] = https://github.com/QubesOS/qubes-issues/issues/531
>> [9] = https://www.qubes-os.org/doc/dom0-tools/qvm-block/
>> [10] = https://xenbits.xen.org/docs/4.6-testing/man/xl.1.html
>> [11] = 
>> https://xenbits.xen.org/docs/4.6-testing/misc/xl-disk-configuration.txt
>> [12] = https://wiki.xenproject.org/wiki/Xen_Networking
>
> ---------------------------------------------------------------
>
> Best Regards,
> Marek Marczykowski-Górecki
> Invisible Things Lab
> A: Because it messes up the order in which people normally read text.
> Q: Why is top-posting such a bad thing?
> -----BEGIN PGP SIGNATURE-----
>
> iQEzBAEBCAAdFiEEhrpukzGPukRmQqkK24/THMrX1ywFAlpMiIsACgkQ24/THMrX
> 1yxQ1wf/duCpjccBCaPsF2u7RzghzITDpV50RSo/TMvyHXM/z2JRcE8oHj+XBMed
> avhpIjRiNYl6BNEKC/qQYzPTS/y5V4sZLSTzVHytQoTM6uK1OVyS1s0JS+SuFyeC
> MilA3T1kyEOsjWH7PEOq5v63DLuSs4D3cBQIzTKtvWLbEKh8LnTCzXvn1+eGtwYQ
> xKV+W0D4RDXyXcl1RDZQqF0fGle2nQIhtB8+HdvDEhqseFQKjACUHyPFqlY2TacI
> WLaBhACrIsMHWGqEB/nIWVqkR7fzjvicH4wD8lD6FYt+UCLXwiC5csE7ajlLTVBn
> IVMMo4CJndztpNBM/gTP5ntt3jJD9Q==
> =UteK
> -----END PGP SIGNATURE-----
>
> You received this message because you are subscribed to the Google Groups 
> "qubes-devel" group.
> To unsubscribe from this group and stop receiving emails from it, send an 
> email to [email protected].
> To post to this group, send email to [email protected].
> To view this discussion on the web visit 
> https://groups.google.com/d/msgid/qubes-devel/20180103073850.GN2653%40mail-itl.
> For more options, visit https://groups.google.com/d/optout.

-- 
You received this message because you are subscribed to the Google Groups 
"qubes-devel" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to [email protected].
To post to this group, send email to [email protected].
To view this discussion on the web visit 
https://groups.google.com/d/msgid/qubes-devel/Nt3jbmnHln_MT-S8bJ44Etbl9xPjhqgt7T7NNfj3xKcavsNcP3-2eou2qcZbrhg1dOfAtRXpTmAg6-VOMVsioLqDBeJh_j2Y9jyCReOOTq4%3D%40protonmail.ch.
For more options, visit https://groups.google.com/d/optout.

Reply via email to