On Wed, Oct 15, 2025 at 5:40 PM Sean Christopherson seanjc@google.com wrote:
On Wed, Oct 15, 2025, Sean Christopherson wrote:
On Wed, Sep 17, 2025, Jim Mattson wrote:
Add a new VM mode, VM_MODE_PXXV57_4K, to support tests that require 5-level paging on x86. This mode sets up a 57-bit virtual address space and sets CR4.LA57 in the guest.
Thinking about this more, unless it's _really_ painful, e.g. because tests assume 4-level paging or 48-bit non-canonical address, I would rather turn VM_MODE_PXXV48_4K into VM_MODE_PXXVXX_4K and have ____vm_create() create the "maximal" VM. That way tests don't need to go out of their way just to use 5-level paging, e.g. a "TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_LA57))" is all that is needed. It will also gives quite a bit of coverage for free, e.g. that save/restore works with and without 5-level paging (contrived example, but you get the point).
The NONCANONICAL #define works for LA57, so hopefully making tests play nice with LA57 is straightforward?
I will see what I can do. :)