From mboxrd@z Thu Jan  1 00:00:00 1970
From: Paolo Bonzini <pbonzini@redhat.com>
Subject: Re: Calling to kvm_mmu_load
Date: Tue, 29 Oct 2013 13:55:58 +0100
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Cc: kvm <kvm@vger.kernel.org>, Jan Kiszka <jan.kiszka@web.de>
To: Arthur Chunqi Li <yzt356@gmail.com>
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Il 29/10/2013 06:39, Arthur Chunqi Li ha scritto:
> What is the dirty page tracking code path? I find a obsoleted flag
> "dirty_page_log_all" in the very previous codes, but I cannot get the
> most recent version of tracking dirty pages.

Basically everything that accesses the dirty_bitmap field of struct
kvm_memory_slot is involved.  It all starts when the
KVM_SET_USER_MEMORY_REGION ioctl is called with the
KVM_MEM_LOG_DIRTY_PAGES flag set.

> Besides, I noticed that memory management in KVM uses the mechanism
> with "struct kvm_memory_slot". How is kvm_memory_slot used with the
> cooperation of Linux memory management?

kvm_memory_slot just maps a host userspace address range to a guest
physical address range.  Cooperation with Linux memory management is
done with the Linux MMU notifiers.  MMU notifiers let KVM know that a
page has been swapped out, and KVM reacts by invalidating the shadow
page tables for the corresponding guest physical address.

Paolo