From: Sean Christopherson <sean.j.christopherson@intel.com>
To: Peter Xu <peterx@redhat.com>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
"Dr . David Alan Gilbert" <dgilbert@redhat.com>,
Andrew Jones <drjones@redhat.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Paolo Bonzini <pbonzini@redhat.com>,
"Michael S . Tsirkin" <mst@redhat.com>,
Jason Wang <jasowang@redhat.com>,
Kevin Tian <kevin.tian@intel.com>
Subject: Re: [PATCH v10 02/14] KVM: Cache as_id in kvm_memory_slot
Date: Mon, 6 Jul 2020 23:17:32 -0700 [thread overview]
Message-ID: <20200707061732.GI5208@linux.intel.com> (raw)
In-Reply-To: <20200703184122.GF6677@xz-x1>
On Fri, Jul 03, 2020 at 02:41:22PM -0400, Peter Xu wrote:
> On Thu, Jul 02, 2020 at 04:08:49PM -0700, Sean Christopherson wrote:
> > On Mon, Jun 01, 2020 at 07:59:45AM -0400, Peter Xu wrote:
> > > Cache the address space ID just like the slot ID. It will be used in
> > > order to fill in the dirty ring entries.
> > >
> > > Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
> > > Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
> > > Signed-off-by: Peter Xu <peterx@redhat.com>
> > > ---
> > > include/linux/kvm_host.h | 1 +
> > > virt/kvm/kvm_main.c | 1 +
> > > 2 files changed, 2 insertions(+)
> > >
> > > diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> > > index 01276e3d01b9..5e7bbaf7a36b 100644
> > > --- a/include/linux/kvm_host.h
> > > +++ b/include/linux/kvm_host.h
> > > @@ -346,6 +346,7 @@ struct kvm_memory_slot {
> > > unsigned long userspace_addr;
> > > u32 flags;
> > > short id;
> > > + u16 as_id;
> > > };
> > >
> > > static inline unsigned long kvm_dirty_bitmap_bytes(struct kvm_memory_slot *memslot)
> > > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> > > index 74bdb7bf3295..ebdd98a30e82 100644
> > > --- a/virt/kvm/kvm_main.c
> > > +++ b/virt/kvm/kvm_main.c
> > > @@ -1243,6 +1243,7 @@ int __kvm_set_memory_region(struct kvm *kvm,
> > > if (!mem->memory_size)
> > > return kvm_delete_memslot(kvm, mem, &old, as_id);
> >
> > This technically needs to set as_id in the deleted memslot. I highly doubt
> > it will ever matter from a functionality perspective, but it'd be confusing
> > to encounter a memslot whose as_id did not match that of its owner.
>
> Yeah it shouldn't matter because as_id is directly passed in to look up the
> pointer of kvm_memslots in kvm_delete_memslot, and memslot->as_id shouldn't be
> further referenced.
>
> I can add a comment above if this can clarify things a bit:
>
> + u16 as_id; /* cache of as_id; only valid if npages != 0 */
Why not just set it? It's a single line of code, and there's more than one
"shouldn't" in the above.
next prev parent reply other threads:[~2020-07-07 6:17 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-01 11:59 [PATCH v10 00/14] KVM: Dirty ring interface Peter Xu
2020-06-01 11:59 ` [PATCH v10 01/14] KVM: X86: Change parameter for fast_page_fault tracepoint Peter Xu
2020-06-01 11:59 ` [PATCH v10 02/14] KVM: Cache as_id in kvm_memory_slot Peter Xu
2020-07-02 23:08 ` Sean Christopherson
2020-07-03 18:41 ` Peter Xu
2020-07-07 6:17 ` Sean Christopherson [this message]
2020-07-07 19:50 ` Peter Xu
2020-07-07 19:56 ` Sean Christopherson
2020-07-07 20:15 ` Peter Xu
2020-07-07 20:26 ` Sean Christopherson
2020-07-07 20:38 ` Peter Xu
2020-06-01 11:59 ` [PATCH v10 03/14] KVM: X86: Don't track dirty for KVM_SET_[TSS_ADDR|IDENTITY_MAP_ADDR] Peter Xu
2020-07-03 0:05 ` Sean Christopherson
2020-07-03 19:02 ` Peter Xu
2020-06-01 11:59 ` [PATCH v10 04/14] KVM: Pass in kvm pointer into mark_page_dirty_in_slot() Peter Xu
2020-06-01 11:59 ` [PATCH v10 05/14] KVM: X86: Implement ring-based dirty memory tracking Peter Xu
2020-06-01 11:59 ` [PATCH v10 06/14] KVM: Make dirty ring exclusive to dirty bitmap log Peter Xu
2020-06-01 11:59 ` [PATCH v10 07/14] KVM: Don't allocate dirty bitmap if dirty ring is enabled Peter Xu
2020-06-01 11:59 ` [PATCH v10 08/14] KVM: selftests: Always clear dirty bitmap after iteration Peter Xu
2020-06-01 11:59 ` [PATCH v10 09/14] KVM: selftests: Sync uapi/linux/kvm.h to tools/ Peter Xu
2020-06-01 11:59 ` [PATCH v10 10/14] KVM: selftests: Use a single binary for dirty/clear log test Peter Xu
2020-06-01 11:59 ` [PATCH v10 11/14] KVM: selftests: Introduce after_vcpu_run hook for dirty " Peter Xu
2020-06-01 11:59 ` [PATCH v10 12/14] KVM: selftests: Add dirty ring buffer test Peter Xu
2020-06-01 12:05 ` [PATCH v10 13/14] KVM: selftests: Let dirty_log_test async for dirty ring test Peter Xu
2020-06-01 12:05 ` [PATCH v10 14/14] KVM: selftests: Add "-c" parameter to dirty log test Peter Xu
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200707061732.GI5208@linux.intel.com \
--to=sean.j.christopherson@intel.com \
--cc=dgilbert@redhat.com \
--cc=drjones@redhat.com \
--cc=jasowang@redhat.com \
--cc=kevin.tian@intel.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mst@redhat.com \
--cc=pbonzini@redhat.com \
--cc=peterx@redhat.com \
--cc=vkuznets@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.