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 v4 07/13] KVM: Just resync arch fields when slots_arch_lock gets reacquired
Date: Fri, 13 Aug 2021 21:33:20 +0200 [thread overview]
Message-ID: <c7d7f681c2f978d03bddea7f5f0d684cdfdb2dd2.1628871413.git.maciej.szmigiero@oracle.com> (raw)
In-Reply-To: <cover.1628871411.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 7000efff1425..272bc86a0e69 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1494,6 +1494,15 @@ 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
@@ -1579,10 +1588,10 @@ 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);
@@ -1599,8 +1608,6 @@ 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:[~2021-08-13 20:02 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-13 19:33 [PATCH v4 00/13] KVM: Scalable memslots implementation Maciej S. Szmigiero
2021-08-13 19:33 ` [PATCH v4 01/13] KVM: x86: Cache total page count to avoid traversing the memslot array Maciej S. Szmigiero
2021-08-13 19:33 ` [PATCH v4 02/13] KVM: x86: Don't call kvm_mmu_change_mmu_pages() if the count hasn't changed Maciej S. Szmigiero
2021-08-13 19:33 ` [PATCH v4 03/13] KVM: Add "old" memslot parameter to kvm_arch_prepare_memory_region() Maciej S. Szmigiero
2021-08-13 19:33 ` [PATCH v4 04/13] KVM: x86: Move n_memslots_pages recalc " Maciej S. Szmigiero
2021-08-13 19:33 ` [PATCH v4 05/13] KVM: Integrate gfn_to_memslot_approx() into search_memslots() Maciej S. Szmigiero
2021-08-18 14:29 ` Claudio Imbrenda
2021-08-13 19:33 ` [PATCH v4 06/13] KVM: Move WARN on invalid memslot index to update_memslots() Maciej S. Szmigiero
2021-08-18 14:29 ` Claudio Imbrenda
2021-08-18 14:35 ` David Hildenbrand
2021-08-18 21:43 ` Maciej S. Szmigiero
2021-08-20 9:27 ` David Hildenbrand
2021-08-13 19:33 ` Maciej S. Szmigiero [this message]
2021-08-13 19:33 ` [PATCH v4 08/13] KVM: Resolve memslot ID via a hash table instead of via a static array Maciej S. Szmigiero
2021-08-13 19:33 ` [PATCH v4 09/13] KVM: Use interval tree to do fast hva lookup in memslots Maciej S. Szmigiero
2021-08-13 19:33 ` [PATCH v4 10/13] KVM: s390: Introduce kvm_s390_get_gfn_end() Maciej S. Szmigiero
2021-08-18 14:31 ` Claudio Imbrenda
2021-08-13 19:33 ` [PATCH v4 11/13] KVM: Keep memslots in tree-based structures instead of array-based ones Maciej S. Szmigiero
2021-08-13 19:33 ` [PATCH v4 12/13] KVM: Optimize gfn lookup in kvm_zap_gfn_range() Maciej S. Szmigiero
2021-08-13 19:33 ` [PATCH v4 13/13] KVM: Optimize overlapping memslots check Maciej S. Szmigiero
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=c7d7f681c2f978d03bddea7f5f0d684cdfdb2dd2.1628871413.git.maciej.szmigiero@oracle.com \
--to=mail@maciej.szmigiero.name \
--cc=aleksandar.qemu.devel@gmail.com \
--cc=borntraeger@de.ibm.com \
--cc=chenhuacai@kernel.org \
--cc=cohuck@redhat.com \
--cc=david@redhat.com \
--cc=frankja@linux.ibm.com \
--cc=imammedo@redhat.com \
--cc=imbrenda@linux.ibm.com \
--cc=james.morse@arm.com \
--cc=jmattson@google.com \
--cc=joro@8bytes.org \
--cc=julien.thierry.kdev@gmail.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=maz@kernel.org \
--cc=paulus@ozlabs.org \
--cc=pbonzini@redhat.com \
--cc=seanjc@google.com \
--cc=suzuki.poulose@arm.com \
--cc=vkuznets@redhat.com \
--cc=wanpengli@tencent.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).