Re: [PATCH] x86/sgx: Add SGX_MemTotal to /proc/meminfo

[Jarkko Sakkinen]

On Mon, 2021-08-23 at 08:15 -0700, Dave Hansen wrote:
> On 8/18/21 6:25 AM, Jarkko Sakkinen wrote:
> > The amount of SGX memory on the system is determined by the BIOS and it
> > varies wildly between systems.  It can be from dozens of MB's on desktops
> > or VM's, up to many GB's on servers.  Just like for regular memory, it is
> > sometimes useful to know the amount of usable SGX memory in the system.
> > 
> > Add SGX_MemTotal field to /proc/meminfo, which shows the total amount of
> > usable SGX memory in the system.  E.g. with 32 MB reserved for SGX from
> > BIOS, the printout would be:
> > 
> > SGX_MemTotal:      22528 kB
> 
> The big question here: Do we want to put purely architecture-specific
> entries in (the currently quite arch-independent) /proc/meminfo?
> 
> The current "DirectMap4k/2M/1G" entries from arch_report_meminfo() are
> arch-specific in their sizes, of course, but the concept is at least
> quite arch-independent.

I started with /proc/meminfo instead of /sys/devices/system/node/*/meminfo
because there is pre-existing arch callback, and secondary because it's also
better fit for my kselftest code.

The same discussion still applies to both files, they probably should follow a
matching pattern.

/Jarkko