Messages in this thread | | | Subject | Re: [PATCH 4/4] KVM: Improve warning report in mark_page_dirty_in_slot() | From | Gavin Shan <> | Date | Thu, 19 Jan 2023 12:15:16 +1100 |
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Hi Sean,
On 1/18/23 2:42 AM, Sean Christopherson wrote: > On Mon, Jan 16, 2023, Gavin Shan wrote: >> There are two warning reports about the dirty ring in the function. >> We have the wrong assumption that the dirty ring is always enabled when >> CONFIG_HAVE_KVM_DIRTY_RING is selected. > > No, it's not a wrong assumption, becuase it's not an assumption. The intent is > to warn irrespective of dirty ring/log enabling. The orignal code actually warned > irrespective of dirty ring support[1], again intentionally. The > CONFIG_HAVE_KVM_DIRTY_RING check was added because s390 can mark pages dirty from > an worker thread[2] and s390 has no plans to support the dirty ring. > > The reason for warning even if dirty ring isn't enabled is so that bots can catch > potential KVM bugs without having to set up a dirty ring or enable dirty logging. > > [1] 2efd61a608b0 ("KVM: Warn if mark_page_dirty() is called without an active vCPU") > [2] e09fccb5435d ("KVM: avoid warning on s390 in mark_page_dirty") >
Thanks for the linker. I was confused when looking at the code, but now it's clear to me. Thanks for your explanation. How about to add a comment there?
/* * The warning is expected when the dirty ring is configured, * but not enabled. */
Thanks, Gavin
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