On Fri, Nov 03, 2017 at 04:30:13PM +0000, Mario.Limonciello@xxxxxxxx wrote: > > -----Original Message----- > > From: Darren Hart [mailto:dvhart@xxxxxxxxxxxxx] > > Sent: Thursday, November 2, 2017 7:50 PM > > To: Limonciello, Mario <Mario_Limonciello@xxxxxxxx> > > Cc: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>; LKML <linux- > > kernel@xxxxxxxxxxxxxxx>; platform-driver-x86@xxxxxxxxxxxxxxx; Andy Lutomirski > > <luto@xxxxxxxxxx>; quasisec@xxxxxxxxxx; pali.rohar@xxxxxxxxx; > > rjw@xxxxxxxxxxxxx; mjg59@xxxxxxxxxx; hch@xxxxxx; Greg KH <greg@xxxxxxxxx>; > > Alan Cox <gnomes@xxxxxxxxxxxxxxxxxxx> > > Subject: Re: [PATCH v12 00/16] Introduce support for Dell SMBIOS over WMI > > > > On Wed, Nov 01, 2017 at 02:25:21PM -0500, Mario Limonciello wrote: > > > The existing way that the dell-smbios helper module and associated > > > other drivers (dell-laptop, dell-wmi) communicate with the platform > > > really isn't secure. It requires creating a buffer in physical > > > DMA32 memory space and passing that to the platform via SMM. > > > > > > Since the platform got a physical memory pointer, you've just got > > > to trust that the platform has only modified (and accessed) memory > > > within that buffer. > > > > > > Dell Platform designers recognize this security risk and offer a > > > safer way to communicate with the platform over ACPI. This is > > > in turn exposed via a WMI interface to the OS. > > > > > > When communicating over WMI-ACPI the communication doesn't occur > > > with physical memory pointers. When the ASL is invoked, the fixed > > > length ACPI buffer is copied to a small operating region. The ASL > > > will invoke the SMI, and SMM will only have access to this operating > > > region. When the ASL returns the buffer is copied back for the OS > > > to process. > > > > > > This method of communication should also deprecate the usage of the > > > dcdbas kernel module and software dependent upon it's interface. > > > Instead offer a character device interface for communicating with this > > > ASL method to allow userspace to use instead. > > > > > > To faciliate that this patch series introduces a generic way for WMI > > > drivers to be able to create discoverable character devices with > > > a predictable IOCTL interface through the WMI bus when desired. > > > Requiring WMI drivers to explicitly ask for this functionality will > > > act as an effective vendor whitelist to character device creation. > > > > > > Some of this work is the basis for what will be a proper interpreter > > > of MOF in the kernel and controls for what drivers will be able to > > > do with that MOF. > > > > > > NOTE: This patch series is intended to go on top of platform-drivers-x86 > > > linux-next. > > > > > > For convenience the entire series including those is also available here: > > > https://github.com/dell/linux/tree/wmi-smbios > > > > Queued for testing, thanks Mario. > > > > -- > > Darren Hart > > VMware Open Source Technology Center > > Thanks Darren. BTW Did you forget to push? I didn't see it at the testing branch: > http://git.infradead.org/users/dvhart/linux-platform-drivers-x86.git/shortlog/refs/heads/testing > > Thanks, > The workflow currently goes first to review-dvhart, which 0-day will pull from, then to testing for integration, then to for-next. I plan to move it to testing today. -- Darren Hart VMware Open Source Technology Center
