On 05/01/2023 11:19 am, Julien Grall wrote: > On 05/01/2023 09:59, Ayan Kumar Halder wrote: >> Hi Julien, > > Hi, > >> I have a clarification. >> >> On 05/01/2023 09:26, Julien Grall wrote: >>> CAUTION: This message has originated from an External Source. Please >>> use proper judgment and caution when opening attachments, clicking >>> links, or responding to this email. >>> >>> >>> Hi Stefano, >>> >>> On 04/01/2023 23:47, Stefano Stabellini wrote: >>>> On Tue, 3 Jan 2023, Michal Orzel wrote: >>>>> Printing memory size in hex without 0x prefix can be misleading, so >>>>> add it. Also, take the opportunity to adhere to 80 chars line length >>>>> limit by moving the printk arguments to the next line. >>>>> >>>>> Signed-off-by: Michal Orzel <[email protected]> >>>>> --- >>>>> Changes in v2: >>>>> - was: "Print memory size in decimal in construct_domU" >>>>> - stick to hex but add a 0x prefix >>>>> - adhere to 80 chars line length limit >>>> >>>> Honestly I prefer decimal but also hex is fine. >>> >>> decimal is perfect for very small values, but as we print the amount in >>> KB it will become a big mess. Here some examples (decimal first, then >>> hexadecimal): >>> >>> 512MB: 524288 vs 0x80000 >>> 555MB: 568320 vs 0x8ac00 >>> 1GB: 1048576 vs 0x100000 >>> 512GB: 536870912 vs 0x20000000 >>> 1TB: 1073741824 vs 0x40000000 >>> >>> For power of two values, you might be able to find your way with >>> decimal. It is more difficult for non power of two unless you have a >>> calculator in hand. >>> >>> The other option I suggested in v1 is to print the amount in KB/GB/MB. >>> Would that be better? >>> >>> That said, to be honest, I am not entirely sure why we are actually >>> printing in KB. It would seems strange that someone would create a >>> guest >>> with memory not aligned to 1MB. >> >> For RTOS (Zephyr and FreeRTOS), it should be possible for guests to >> have memory less than 1 MB, isn't it ? > > Yes. So does XTF. But most of the users are likely going allocate at > least 1MB (or even 2MB to reduce the TLB pressure). > > So it would be better to print the value in a way that is more > meaningful for the majority of the users. > >>> So I would consider to check the size is 1MB-aligned and then print the > > I will retract my suggestion to check the size. There are technically > no restriction to run a guest with a size not aligned to 1MB. > Although, it would still seem strange.
I have a need to extend tools/tests/tsx with a VM that is a single 4k page. Something which can execute CPUID in the context of a VM and cross-check the results with what the "toolstack" (test) tried to configure. Xen is buggy if it cannot operate a VM which looks like that, and a bonus of explicitly testing like this is that it helps to remove inappropriate checks. ~Andrew
