On 02/07/18 14:50, Marc Zyngier wrote:
On 29/06/18 12:15, Suzuki K Poulose wrote:
So far we have restricted the IPA size of the VM to the default
value (40bits). Now that we can manage the IPA size per VM and
support dynamic stage2 page tables, allow VMs to have larger IPA.
This is done by setting the IPA limit to the one supported by
the hardware and kernel. This patch also moves the check for
the default IPA size support to kvm_get_ipa_limit().
Since the stage2 page table code is dependent on the stage1
page table, we always ensure that :
Number of Levels at Stage1 >= Number of Levels at Stage2
So we limit the IPA to make sure that the above condition
is satisfied. This will affect the following combinations
of VA_BITS and IPA for different page sizes.
39bit VA, 4K - IPA > 43 (Upto 48)
36bit VA, 16K - IPA > 40 (Upto 48)
42bit VA, 64K - IPA > 46 (Upto 52)
I'm not sure I get it. Are these the IPA sizes that we forbid based on
the host VA size and page size configuration?
Yes, thats right.
If so, can you rewrite
this as:
host configuration | unsupported IPA range
39bit VA, 4k | [44, 48]
36bit VA, 16K | [41, 48]
42bit VA, 64k | [47, 52]
and say that all the other combinations are supported?
Sure, that looks much better. Thanks
Suzuki
