Messages in this thread | | | Date | Thu, 17 Jul 2014 21:34:20 +0800 | From | Tang Chen <> | Subject | Re: [PATCH v2 5/5] kvm, mem-hotplug: Do not pin apic access page in memory. |
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Hi Gleb,
On 07/15/2014 08:40 PM, Gleb Natapov wrote: ...... >> >> And yes, we have the problem you said here. We can migrate the page while L2 >> vm is running. >> So I think we should enforce L2 vm to exit to L1. Right ? >> > We can request APIC_ACCESS_ADDR reload during L2->L1 vmexit emulation, so > if APIC_ACCESS_ADDR changes while L2 is running it will be reloaded for L1 too. >
Sorry, I think I don't quite understand the procedure you are talking about here.
Referring to the code, I think we have three machines: L0(host), L1 and L2. And we have two types of vmexit: L2->L1 and L2->L0. Right ?
We are now talking about this case: L2 and L1 shares the apic page.
Using patch 5/5, when apic page is migrated on L0, mmu_notifier will notify L1, and update L1's VMCS. At this time, we are in L0, not L2. Why cannot we update the L2's VMCS at the same time ? Is it because we don't know how many L2 vms there are in L1 ?
And, when will L2->L1 vmexit happen ? When we enforce L1 to exit to L0 by calling make_all_cpus_request(), is L2->L1 vmexit triggered automatically ?
Thanks.
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