On Wed, Feb 27, 2019 at 12:04:49PM -0300, Murilo Opsfelder Araujo wrote: > Hi, David. > > On Wed, Feb 27, 2019 at 10:19:20AM +1100, David Gibson wrote: > > On Tue, Feb 26, 2019 at 04:11:40PM -0300, Murilo Opsfelder Araujo wrote: > > > On Tue, Feb 26, 2019 at 02:08:30PM -0300, Murilo Opsfelder Araujo wrote: > > > > Hi, Maxiwell. > > > > > > > > On Tue, Feb 26, 2019 at 11:21:26AM -0300, Maxiwell S. Garcia wrote: > > > > > On Tue, Feb 26, 2019 at 02:21:03PM +1100, David Gibson wrote: > > > > > > On Mon, Feb 25, 2019 at 08:20:09PM -0300, Murilo Opsfelder Araujo > > > > > > wrote: > > > > > > > Hi, Maxiwell. > > > > > > > > > > > > > > On Mon, Feb 25, 2019 at 01:23:25PM -0300, Maxiwell S. Garcia > > > > > > > wrote: > > > > > > > > This adds a handler for ibm,get-vpd RTAS calls, allowing pseries > > > > > > > > guest to collect host information. It is disabled by default to > > > > > > > > avoid unwanted information leakage. To enable it, use: > > > > > > > > ‘-M pseries,vpd-export=on’ > > > > > > > > > > > > > > The patch for setting host-serial and host-model already landed > > > > > > > Gibson's > > > > > > > ppc-for-4.0 branch: > > > > > > > > > > > > > > commit 9e584f45868f6945c1282c938278038cba0e4af2 > > > > > > > Author: Prasad J Pandit <p...@fedoraproject.org> > > > > > > > Date: Mon Feb 18 23:43:49 2019 +0530 > > > > > > > > > > > > > > ppc: add host-serial and host-model machine attributes > > > > > > > (CVE-2019-8934) > > > > > > > > > > > > > > > > > > > > > QEMU should only return host-serial and host-model from the host > > > > > > > if the > > > > > > > following combination of parameters are provided: > > > > > > > > > > > > > > -M host-serial=passthrough,host-model=passthrough,vpd-export=on > > > > > > > > > > > > > > If host-serial or host-model are set with a user-string, > > > > > > > ibm,get-vpd should > > > > > > > honor these values and return them, not exposing host information > > > > > > > by accident. > > > > > > > > > > > > > > I'm not even sure if we need vpd-export=<bool> setting. Its logic > > > > > > > could be > > > > > > > derived from the presence of host-serial=passthrough and > > > > > > > host-model=passthrough > > > > > > > options. > > > > > > > > > > > > > > What do you think? > > > > > > > > > > > > That's an excellent point - I hadn't thought through the fact that > > > > > > this is the same information exposed by those properties. I do > > > > > > indeed > > > > > > think that exposing the same information set in those properties - > > > > > > and > > > > > > thereby avoiding the new machine option - would be a better plan. > > > > > > > > > > > > > > > > I saw that the patch was applied. So I will work in another patch > > > > > to use these properties and remove the export-vpd option. > > > > > > > > > > Another thing that I thought the fact that 'host-serial' and > > > > > 'host-model' > > > > > nodes in Device Tree are not in accordance with LoPAPR document. What > > > > > you think in use only get-vpd to get these information and remove > > > > > nodes from device tree? > > > > > > > > Both "system-id" and "model" properties are described in the section > > > > "3.3.2.1 > > > > Root Node Properties" of the "Device Tree Bindings: Linux on Power > > > > Architecture > > > > Reference" document: > > > > > > > > https://members.openpowerfoundation.org/wg/SYSSW/document/1455 > > > > > > I replied too early. As Maxiwell explained to me (thanks Max!), guest can > > > end up > > > having the following entries under /proc/device-tree/ (among other > > > entries): > > > > > > $ cat host-serial > > > 12A3B4C > > > > > > $ cat host-model > > > 1234-56A > > > > > > $ cat system-id > > > c7b62da9-3d0c-44f9-8edb-2318271f3c1a > > > > > > $ cat model > > > IBM pSeries (emulated by qemu) > > > > > > Where: > > > > > > - host-serial/host-model: depend on "-M host-serial" and "-M host-model" > > > machine options. > > > > > > - system-id: created when "-uuid <val>" exists in qemu command line > > > options. > > > > > > - model: hard-coded. > > > > > > With this patch, RTAS ibm,get-vpd call will return "system-id" and > > > "model" from > > > the host, not from the guest. I found this confusing. > > > > Hrm. I found the bit in LoPAPR describing how ibm,get-vpd operates, > > but not something describing the actual data that appears within it. > > Where's that described? It'd be nice to check if those values are > > supposed to be describing the host or the guest. > > Are you asking about the fields of the ibm,vpd property? They are described in > Table 11.2 "LoPAPR VPD Fields" of this LoPAPR document: > > https://members.openpowerfoundation.org/wg/SYSSW/document/1461
That document appears to be only available to openpower members, which I'm not. I found Table 160 in my copy of LoPAPR (1.1) though, which looks like it has the same stuff. I wonder if I should be trying to get a more recent LoPAPR. -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson
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