From: "Maciej S. Szmigiero" <mail@maciej.szmigiero.name>
To: Paolo Bonzini <pbonzini@redhat.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>,
Igor Mammedov <imammedo@redhat.com>,
Marc Zyngier <maz@kernel.org>, James Morse <james.morse@arm.com>,
Julien Thierry <julien.thierry.kdev@gmail.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Huacai Chen <chenhuacai@kernel.org>,
Aleksandar Markovic <aleksandar.qemu.devel@gmail.com>,
Paul Mackerras <paulus@ozlabs.org>,
Christian Borntraeger <borntraeger@de.ibm.com>,
Janosch Frank <frankja@linux.ibm.com>,
David Hildenbrand <david@redhat.com>,
Cornelia Huck <cohuck@redhat.com>,
Claudio Imbrenda <imbrenda@linux.ibm.com>,
Joerg Roedel <joro@8bytes.org>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v5 07/13] KVM: Just resync arch fields when slots_arch_lock gets reacquired
Date: Mon, 20 Sep 2021 23:38:55 +0200 [thread overview]
Message-ID: <311810ebd1111bed50d931d424297384171afc36.1632171479.git.maciej.szmigiero@oracle.com> (raw)
In-Reply-To: <cover.1632171478.git.maciej.szmigiero@oracle.com>
From: "Maciej S. Szmigiero" <maciej.szmigiero@oracle.com>
There is no need to copy the whole memslot data after releasing
slots_arch_lock for a moment to install temporary memslots copy in
kvm_set_memslot() since this lock only protects the arch field of each
memslot.
Just resync this particular field after reacquiring slots_arch_lock.
Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
---
virt/kvm/kvm_main.c | 17 ++++++++++++-----
1 file changed, 12 insertions(+), 5 deletions(-)
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 348fae880189..48d182840060 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1482,6 +1482,15 @@ static void kvm_copy_memslots(struct kvm_memslots *to,
memcpy(to, from, kvm_memslots_size(from->used_slots));
}
+static void kvm_copy_memslots_arch(struct kvm_memslots *to,
+ struct kvm_memslots *from)
+{
+ int i;
+
+ for (i = 0; i < from->used_slots; i++)
+ to->memslots[i].arch = from->memslots[i].arch;
+}
+
/*
* Note, at a minimum, the current number of used slots must be allocated, even
* when deleting a memslot, as we need a complete duplicate of the memslots for
@@ -1567,10 +1576,10 @@ static int kvm_set_memslot(struct kvm *kvm,
/*
* The arch-specific fields of the memslots could have changed
* between releasing the slots_arch_lock in
- * install_new_memslots and here, so get a fresh copy of the
- * slots.
+ * install_new_memslots and here, so get a fresh copy of these
+ * fields.
*/
- kvm_copy_memslots(slots, __kvm_memslots(kvm, as_id));
+ kvm_copy_memslots_arch(slots, __kvm_memslots(kvm, as_id));
}
r = kvm_arch_prepare_memory_region(kvm, old, new, mem, change);
@@ -1587,8 +1596,6 @@ static int kvm_set_memslot(struct kvm *kvm,
out_slots:
if (change == KVM_MR_DELETE || change == KVM_MR_MOVE) {
- slot = id_to_memslot(slots, old->id);
- slot->flags &= ~KVM_MEMSLOT_INVALID;
slots = install_new_memslots(kvm, as_id, slots);
} else {
mutex_unlock(&kvm->slots_arch_lock);
next prev parent reply other threads:[~2021-09-20 21:42 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-20 21:38 [PATCH v5 00/13] KVM: Scalable memslots implementation Maciej S. Szmigiero
2021-09-20 21:38 ` [PATCH v5 01/13] KVM: x86: Cache total page count to avoid traversing the memslot array Maciej S. Szmigiero
2021-10-19 22:24 ` Sean Christopherson
2021-10-19 22:31 ` Sean Christopherson
2021-10-20 18:40 ` Maciej S. Szmigiero
2021-10-20 18:41 ` Maciej S. Szmigiero
2021-10-20 19:01 ` Sean Christopherson
2021-11-01 22:29 ` Sean Christopherson
2021-11-03 11:59 ` Maciej S. Szmigiero
2021-11-03 14:47 ` Sean Christopherson
2021-11-03 15:38 ` Maciej S. Szmigiero
2021-09-20 21:38 ` [PATCH v5 02/13] KVM: x86: Don't call kvm_mmu_change_mmu_pages() if the count hasn't changed Maciej S. Szmigiero
2021-09-20 21:38 ` [PATCH v5 03/13] KVM: Add "old" memslot parameter to kvm_arch_prepare_memory_region() Maciej S. Szmigiero
2021-09-20 21:38 ` [PATCH v5 04/13] KVM: x86: Move n_memslots_pages recalc " Maciej S. Szmigiero
2021-10-19 22:38 ` Sean Christopherson
2021-10-20 18:41 ` Maciej S. Szmigiero
2021-09-20 21:38 ` [PATCH v5 05/13] KVM: Integrate gfn_to_memslot_approx() into search_memslots() Maciej S. Szmigiero
2021-10-19 23:38 ` Sean Christopherson
2021-10-20 18:41 ` Maciej S. Szmigiero
2021-09-20 21:38 ` [PATCH v5 06/13] KVM: Move WARN on invalid memslot index to update_memslots() Maciej S. Szmigiero
2021-10-19 23:42 ` Sean Christopherson
2021-09-20 21:38 ` Maciej S. Szmigiero [this message]
2021-10-19 23:55 ` [PATCH v5 07/13] KVM: Just resync arch fields when slots_arch_lock gets reacquired Sean Christopherson
2021-10-20 18:41 ` Maciej S. Szmigiero
2021-10-20 18:57 ` Sean Christopherson
2021-10-20 18:58 ` Maciej S. Szmigiero
2021-09-20 21:38 ` [PATCH v5 08/13] KVM: Resolve memslot ID via a hash table instead of via a static array Maciej S. Szmigiero
2021-10-20 0:43 ` Sean Christopherson
2021-10-20 18:42 ` Maciej S. Szmigiero
2021-10-20 22:39 ` Sean Christopherson
2021-10-21 14:15 ` Maciej S. Szmigiero
2021-09-20 21:38 ` [PATCH v5 09/13] KVM: Use interval tree to do fast hva lookup in memslots Maciej S. Szmigiero
2021-10-26 18:19 ` Sean Christopherson
2021-10-26 18:46 ` Maciej S. Szmigiero
2021-09-20 21:38 ` [PATCH v5 10/13] KVM: s390: Introduce kvm_s390_get_gfn_end() Maciej S. Szmigiero
2021-09-20 21:38 ` [PATCH v5 11/13] KVM: Keep memslots in tree-based structures instead of array-based ones Maciej S. Szmigiero
2021-10-27 0:36 ` Sean Christopherson
2021-10-27 23:54 ` Sean Christopherson
2021-10-28 22:22 ` Sean Christopherson
2021-09-20 21:39 ` [PATCH v5 12/13] KVM: Optimize gfn lookup in kvm_zap_gfn_range() Maciej S. Szmigiero
2021-10-20 23:47 ` Sean Christopherson
2021-10-21 14:16 ` Maciej S. Szmigiero
2021-10-21 16:30 ` Sean Christopherson
2021-10-21 21:44 ` Maciej S. Szmigiero
2021-09-20 21:39 ` [PATCH v5 13/13] KVM: Optimize overlapping memslots check Maciej S. Szmigiero
2021-10-26 18:59 ` Sean Christopherson
2021-10-27 13:48 ` Maciej S. Szmigiero
2021-10-28 17:53 ` Sean Christopherson
2021-10-29 16:23 ` Maciej S. Szmigiero
2021-10-30 0:32 ` Sean Christopherson
2021-10-19 22:07 ` [PATCH v5 00/13] KVM: Scalable memslots implementation Sean Christopherson
2021-10-20 18:40 ` Maciej S. Szmigiero
2021-10-20 19:58 ` Sean Christopherson
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