On Sep 26, 2014, at 4:42 AM, Christoffer Dall wrote: Hi, Christoffer > This patch adds the necessary support for all host kernel PGSIZE and > VA_SPACE configuration options for both EL2 and the Stage-2 page tables. > > However, for 40bit and 42bit PARange systems, the architecture mandates > that VTCR_EL2.SL0 is maximum 1, resulting in fewer levels of stage-2 > pagge tables than levels of host kernel page tables. At the same time, > systems with a PARange > 42bit, we limit the IPA range by always setting > VTCR_EL2.T0SZ to 24. > > To solve the situation with different levels of page tables for Stage-2 > translation than the host kernel page tables, we allocate a dummy PGD > with pointers to our actual inital level Stage-2 page table, in order > for us to reuse the kernel pgtable manipulation primitives. Reproducing > all these in KVM does not look pretty and unnecessarily complicates the > 32-bit side. This is a very similar idea suggested by Steve Capper to deal with swapper table when I worked on 4 level solution. I believe that dummy PGD approach can handle all combinations described in ARMv8 architecture. > Systems with a PARange < 40bits are not yet supported. > > [ I have reworked this patch from its original form submitted by > Jungseok to take the architecture constraints into consideration. > There were too many changes from the original patch for me to > preserve the authorship. Thanks to Catalin Marinas for his help in > figuring out a good solution to this challenge. I have also fixed > various bugs and missing error code handling from the original > patch. - Christoffer ] No doubt. This is yours :) I really thank you for picking up the patch and writing this graceful solution. At first glance, it looks good except some unnecessary newlines. I will leave comments after reading the patches carefully. Best Regards Jungseok Lee-- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
