On 2014-06-18 13:36, Valentine Sinitsyn wrote: > Hi all, > > I'm using a KVM/Qemu nested SVM setup to debug another hypervisor > (Jailhouse) I contribute to. IOW, the scheme is: AMD64 Linux host > running [paravirtualized] AMD64 Linux guest (the same kernel as the > host) running Jailhouse. > > Jailhouse, in turn, uses Nested Paging to virtualize xAPIC: APIC page > (0xfee00000, no APIC remapping) is mapped read-only into Jailhouse's > guests. This of course implies that APIC page appears to Jailhouse > guests as uncacheable (UC). > > Is it achievable in the setup I described, or do I need to run my code > on a real hardware to make the APIC page accesses in Jailhouse guests > uncacheable? If we want to provide useful nested SVM support, this must be feasible. If there is a bug, it has to be fixed. Maybe you can describe how you configured the involved units (NPT structures, guest / host PAR, MTRR etc.). Even better would be a test case based on kvm-unit-tests (see [1], x86/svm.c) that replicates the observed behavior. If it reveals a bug, this test would be very valuable for making sure it remains fixed (once that is done). Jan [1] https://git.kernel.org/cgit/virt/kvm/kvm-unit-tests.git -- Siemens AG, Corporate Technology, CT RTC ITP SES-DE Corporate Competence Center Embedded Linux -- 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
