Re: [PATCH 07/10] KVM: PPC: Add PAPR hypercall code for PR mode

Am 12.08.2011 um 05:35 schrieb David Gibson [off-list ref]:

On Tue, Aug 09, 2011 at 06:31:45PM +0200, Alexander Graf wrote:

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When running a PAPR guest, we need to handle a few hypercalls in kernel s=

pace,

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most prominently the page table invalidation (to sync the shadows).
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So this patch adds handling for a few PAPR hypercalls to PR mode KVM. I t=

ried

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to share the code with HV mode, but it ended up being a lot easier this w=

ay

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around, as the two differ too much in those details.

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Are these strictly necessary, or just an optimization?  Because you're
using the space allocated by qemu for the guest hash table, it seems
to be you could just let h_enter fall through to qemu which will put
the right thing into the guest hash table which you can then walk in
the kernel translation code.

Every time a PTE can be invalidated, we need to do so in kvm to keep the SPT=
 in sync. IIRC h_enter can evict/overwrite a previous entry, so we need to h=
andle it in kvm as well :). Removal definitely needs to happin in-kernel.


Alex

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