On 2013-03-22 17:45, Jan Kiszka wrote: > On 2013-03-22 07:23, Nakajima, Jun wrote: >> On Mon, Mar 4, 2013 at 8:45 PM, Nakajima, Jun <jun.nakajima@xxxxxxxxx> wrote: >>> I have some updates on this. We rebased the patched to the latest KVM >>> (L0). It turned out that the version of L1 KVM/Linux matters. At that >>> time, actually I used v3.7 kernel for L1, and the L2 didn't work as I >>> described above. If I use v3.5 or older for L1, L2 works with the EPT >>> patches. So, I guess some changes made to v3.6 might have exposed a >>> bug with the nested EPT patches or somewhere. We are looking at the >>> changes to root-cause it. >>> >> >> Finally I've had more time to work on this, and I think I've fixed >> this. The problem was that the exit qualification for EPT violation >> (to L1) was not accurate (enough). And I needed to save the exit >> qualification upon EPT violation somewhere. Today, that information is >> converted to error_code (see below), and we lose the information. We >> need to use at least the lower 3 bits when injecting EPT violation to >> the L1 VMM. I tried to use the upper bytes of error_code to pass part >> of the exit qualification, but it didn't work well. Any suggestion for >> the place to store the value? kvm_vcpu? >> >> ... >> /* It is a write fault? */ >> error_code = exit_qualification & (1U << 1); >> /* ept page table is present? */ >> error_code |= (exit_qualification >> 3) & 0x1; >> >> return kvm_mmu_page_fault(vcpu, gpa, error_code, NULL, 0); > > I don't have a full picture (already asked you to post / git-push your > intermediate state), but nested related states typically go to > nested_vmx, thus vcpu_vmx. Ping regarding publication. I'm about to redo your porting work as we are making no progress. Jan
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