Re: [PATCH RFC] paravirt_ops: refactor struct paravirt_ops into smaller pv_*_ops
From: Zachary Amsden <hidden>
Date: 2007-09-28 19:02:36
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On Fri, 2007-09-28 at 11:49 -0700, Jeremy Fitzhardinge wrote:
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We shouldn't need to export pv_init_ops.No. The only ones I export are: EXPORT_SYMBOL_GPL(pv_time_ops); EXPORT_SYMBOL_GPL(pv_cpu_ops); EXPORT_SYMBOL_GPL(pv_mmu_ops); EXPORT_SYMBOL_GPL(pv_apic_ops); EXPORT_SYMBOL (pv_irq_ops);
Nicely done. I know of some out of tree modules which use part of the pv_cpu_ops and pv_mmu_ops, but we should not worry about such things, and it turns out those modules don't need to be virtualized anyway.
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It is debatable whether CR2/CR3 should be part of CPU or MMU ops.Yeah, I was in two minds. CR3, at least, should be grouped with the other tlb operations, wherever they go. And while they're privileged CPU instructions (cpu_ops), they're more logically related to the rest of the mmu state. On the other hand, we could have an ops structure specifically dedicated to pagetable manipulations, and put the cr3/tlb ops elsewhere.
I'm not against either approach. I think the way you did it is fine. If it were up to me, I would probably have driven myself crazy splitting hairs on it until I was bald.
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Also, can we drop write_cr2? It isn't used anywhere, so the only reason to keep it is symmetry. Which was a fine argument when it was an inline, but now it just adds unused junk to the code.I think its used in some cpu state save/restore code, but its not relevant to pv-ops.
Ah yes, it is used there. We actually exercise some of those paths, but they don't need to be strictly virtualized. Zach