From b10a038e84d188e15819058b2978b2daa9853aeb Mon Sep 17 00:00:00 2001 From: Ben Gardon Date: Tue, 18 May 2021 10:34:11 -0700 Subject: KVM: mmu: Add slots_arch_lock for memslot arch fields Add a new lock to protect the arch-specific fields of memslots if they need to be modified in a kvm->srcu read critical section. A future commit will use this lock to lazily allocate memslot rmaps for x86. Signed-off-by: Ben Gardon Message-Id: <20210518173414.450044-5-bgardon@google.com> [Add Documentation/ hunk. - Paolo] Signed-off-by: Paolo Bonzini --- include/linux/kvm_host.h | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'include/linux') diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 8583ed3ff344..11b9b11a5e9b 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -523,6 +523,15 @@ struct kvm { #endif /* KVM_HAVE_MMU_RWLOCK */ struct mutex slots_lock; + + /* + * Protects the arch-specific fields of struct kvm_memory_slots in + * use by the VM. To be used under the slots_lock (above) or in a + * kvm->srcu critical section where acquiring the slots_lock would + * lead to deadlock with the synchronize_srcu in + * install_new_memslots. + */ + struct mutex slots_arch_lock; struct mm_struct *mm; /* userspace tied to this vm */ struct kvm_memslots __rcu *memslots[KVM_ADDRESS_SPACE_NUM]; struct kvm_vcpu *vcpus[KVM_MAX_VCPUS]; -- cgit v1.3