Hi Julien, Julien Grall writes:
> Hi Volodymyr, > > On 9/11/19 7:48 PM, Volodymyr Babchuk wrote: >> >> Julien Grall writes: >> >>> Hi Volodymyr, >>> >>> On 8/23/19 7:48 PM, Volodymyr Babchuk wrote: >>>> We want to limit number of calls to lookup_and_pin_guest_ram_addr() >>>> per one request. There are two ways to do this: either preempt >>>> translate_noncontig() or to limit size of one shared buffer size. >>>> >>>> It is quite hard to preempt translate_noncontig(), because it is deep >>>> nested. So we chose second option. We will allow 512 pages per one >>>> shared buffer. This does not interfere with GP standard, as it >>>> requires that size limit for shared buffer should be at lest 512kB. >>> >>> Do you mean "least" instead of "lest"? >> Yes >> >>> If so, why 512 pages (i.e 1MB) >>> is plenty enough for most of the use cases? What does "xtest" consist >>> on? >> Bigger buffer xtest tries to allocate is mere 32KB. I believe that 1MB >> is enough for the most cases, because OP-TEE itself have a very limited >> resources. But this value is chosen arbitrary. > > Could we potentially reduce to let say 512KB (or maybe lower) if xtest > only allocate 32KB? Potentially - yes. But only to 512KB if we want to be compatible with the Global Platform specification. Why are you asking, though? -- Volodymyr Babchuk at EPAM _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
