From: Ben Gardon <bgardon@google.com>
To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: Paolo Bonzini <pbonzini@redhat.com>, Peter Xu <peterx@redhat.com>,
Sean Christopherson <seanjc@google.com>,
Peter Shier <pshier@google.com>,
Yulei Zhang <yulei.kernel@gmail.com>,
Wanpeng Li <kernellwp@gmail.com>,
Xiao Guangrong <xiaoguangrong.eric@gmail.com>,
Kai Huang <kai.huang@intel.com>,
Keqian Zhu <zhukeqian1@huawei.com>,
David Hildenbrand <david@redhat.com>,
Ben Gardon <bgardon@google.com>
Subject: [PATCH v4 3/7] KVM: mmu: Refactor memslot copy
Date: Tue, 11 May 2021 10:16:06 -0700 [thread overview]
Message-ID: <20210511171610.170160-4-bgardon@google.com> (raw)
In-Reply-To: <20210511171610.170160-1-bgardon@google.com>
Factor out copying kvm_memslots from allocating the memory for new ones
in preparation for adding a new lock to protect the arch-specific fields
of the memslots.
No functional change intended.
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Ben Gardon <bgardon@google.com>
---
virt/kvm/kvm_main.c | 23 ++++++++++++++++-------
1 file changed, 16 insertions(+), 7 deletions(-)
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 6b4feb92dc79..9e106742b388 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1306,6 +1306,18 @@ static struct kvm_memslots *install_new_memslots(struct kvm *kvm,
return old_memslots;
}
+static size_t kvm_memslots_size(int slots)
+{
+ return sizeof(struct kvm_memslots) +
+ (sizeof(struct kvm_memory_slot) * slots);
+}
+
+static void kvm_copy_memslots(struct kvm_memslots *from,
+ struct kvm_memslots *to)
+{
+ memcpy(to, from, kvm_memslots_size(from->used_slots));
+}
+
/*
* 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
@@ -1315,19 +1327,16 @@ static struct kvm_memslots *kvm_dup_memslots(struct kvm_memslots *old,
enum kvm_mr_change change)
{
struct kvm_memslots *slots;
- size_t old_size, new_size;
-
- old_size = sizeof(struct kvm_memslots) +
- (sizeof(struct kvm_memory_slot) * old->used_slots);
+ size_t new_size;
if (change == KVM_MR_CREATE)
- new_size = old_size + sizeof(struct kvm_memory_slot);
+ new_size = kvm_memslots_size(old->used_slots + 1);
else
- new_size = old_size;
+ new_size = kvm_memslots_size(old->used_slots);
slots = kvzalloc(new_size, GFP_KERNEL_ACCOUNT);
if (likely(slots))
- memcpy(slots, old, old_size);
+ kvm_copy_memslots(old, slots);
return slots;
}
--
2.31.1.607.g51e8a6a459-goog
next prev parent reply other threads:[~2021-05-11 17:16 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-11 17:16 [PATCH v4 0/7] Lazily allocate memslot rmaps Ben Gardon
2021-05-11 17:16 ` [PATCH v4 1/7] KVM: x86/mmu: Deduplicate rmap freeing Ben Gardon
2021-05-11 17:16 ` [PATCH v4 2/7] KVM: x86/mmu: Factor out allocating memslot rmap Ben Gardon
2021-05-11 17:56 ` Sean Christopherson
2021-05-11 18:17 ` Ben Gardon
2021-05-11 18:56 ` David Hildenbrand
2021-05-11 17:16 ` Ben Gardon [this message]
2021-05-11 18:47 ` [PATCH v4 3/7] KVM: mmu: Refactor memslot copy Sean Christopherson
2021-05-11 17:16 ` [PATCH v4 4/7] KVM: mmu: Add slots_arch_lock for memslot arch fields Ben Gardon
2021-05-11 18:55 ` Sean Christopherson
2021-05-11 19:21 ` Sean Christopherson
2021-05-11 19:29 ` Paolo Bonzini
2021-05-11 17:16 ` [PATCH v4 5/7] KVM: x86/mmu: Add a field to control memslot rmap allocation Ben Gardon
2021-05-11 17:16 ` [PATCH v4 6/7] KVM: x86/mmu: Skip rmap operations if rmaps not allocated Ben Gardon
2021-05-11 19:51 ` Sean Christopherson
2021-05-11 17:16 ` [PATCH v4 7/7] KVM: x86/mmu: Lazily allocate memslot rmaps Ben Gardon
2021-05-11 18:57 ` Sean Christopherson
2021-05-11 20:03 ` Sean Christopherson
2021-05-11 20:04 ` Sean Christopherson
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