From: David Hildenbrand <david@redhat.com>
To: Ben Gardon <bgardon@google.com>,
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>
Subject: Re: [PATCH v3 3/8] KVM: mmu: Refactor memslot copy
Date: Fri, 7 May 2021 09:48:20 +0200 [thread overview]
Message-ID: <7c2be781-7a10-a1b3-a8e8-d26ff4100746@redhat.com> (raw)
In-Reply-To: <20210506184241.618958-4-bgardon@google.com>
On 06.05.21 20:42, Ben Gardon wrote:
> 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.
>
> 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 2799c6660cce..c8010f55e368 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);
no need for the extra set of parentheses
> +}
> +
> +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;
> }
>
Reviewed-by: David Hildenbrand <david@redhat.com>
--
Thanks,
David / dhildenb
next prev parent reply other threads:[~2021-05-07 7:48 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-06 18:42 [PATCH v3 0/8] Lazily allocate memslot rmaps Ben Gardon
2021-05-06 18:42 ` [PATCH v3 1/8] KVM: x86/mmu: Deduplicate rmap freeing Ben Gardon
2021-05-07 7:42 ` David Hildenbrand
2021-05-06 18:42 ` [PATCH v3 2/8] KVM: x86/mmu: Factor out allocating memslot rmap Ben Gardon
2021-05-07 7:46 ` David Hildenbrand
2021-05-10 16:29 ` Ben Gardon
2021-05-06 18:42 ` [PATCH v3 3/8] KVM: mmu: Refactor memslot copy Ben Gardon
2021-05-07 7:48 ` David Hildenbrand [this message]
2021-05-06 18:42 ` [PATCH v3 4/8] KVM: mmu: Add slots_arch_lock for memslot arch fields Ben Gardon
2021-05-06 18:42 ` [PATCH v3 5/8] KVM: x86/mmu: Add a field to control memslot rmap allocation Ben Gardon
2021-05-06 23:44 ` Ben Gardon
2021-05-07 7:50 ` David Hildenbrand
2021-05-07 8:28 ` Paolo Bonzini
2021-05-10 16:14 ` Ben Gardon
2021-05-10 16:33 ` Paolo Bonzini
2021-05-10 16:37 ` Ben Gardon
2021-05-06 18:42 ` [PATCH v3 6/8] KVM: x86/mmu: Skip rmap operations if rmaps not allocated Ben Gardon
2021-05-06 23:07 ` kernel test robot
2021-05-06 18:42 ` [PATCH v3 7/8] KVM: x86/mmu: Protect rmaps independently with SRCU Ben Gardon
2021-05-06 23:58 ` kernel test robot
2021-05-07 0:56 ` kernel test robot
2021-05-07 8:42 ` Paolo Bonzini
2021-05-10 17:45 ` Sean Christopherson
2021-05-10 17:53 ` Paolo Bonzini
2021-05-10 18:28 ` Sean Christopherson
2021-05-11 16:22 ` Ben Gardon
2021-05-11 16:45 ` Paolo Bonzini
2021-05-06 18:42 ` [PATCH v3 8/8] KVM: x86/mmu: Lazily allocate memslot rmaps Ben Gardon
2021-05-07 1:10 ` kernel test robot
2021-05-07 8:28 ` Paolo Bonzini
2021-05-07 7:40 ` [PATCH v3 0/8] " David Hildenbrand
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