KVM: reuse memslot in kvm_write_guest_page (251eb841) · Commits · 戴 / test

Caching memslot value and using mark_page_dirty_in_slot() avoids another O(log N) search when dirtying the page. Signed-off-by:

Radim Krčmář <rkrcmar@redhat.com> Message-Id: <1428695247-27603-1-git-send-email-rkrcmar@redhat.com> Signed-off-by:

virt/kvm/kvm_main.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -1590,15 +1590,17 @@ int kvm_write_guest_page(struct kvm kvm, gfn_t gfn, const void data,
		int offset, int len)
		{
		int r;
		struct kvm_memory_slot *memslot;
		unsigned long addr;

		addr = gfn_to_hva(kvm, gfn);
		memslot = gfn_to_memslot(kvm, gfn);
		addr = gfn_to_hva_memslot(memslot, gfn);
		if (kvm_is_error_hva(addr))
		return -EFAULT;
		r = __copy_to_user((void __user *)addr + offset, data, len);
		if (r)
		return -EFAULT;
		mark_page_dirty(kvm, gfn);
		mark_page_dirty_in_slot(kvm, memslot, gfn);
		return 0;
		}
		EXPORT_SYMBOL_GPL(kvm_write_guest_page);