KVM: x86/mmu: Use an rwlock for the x86 MMU
Add a read / write lock to be used in place of the MMU spinlock on x86.
The rwlock will enable the TDP MMU to handle page faults, and other
operations in parallel in future commits.
Reviewed-by: Peter Feiner <pfeiner@google.com>
Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <20210202185734.1680553-19-bgardon@google.com>
[Introduce virt/kvm/mmu_lock.h - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 912fc41..b3b1cce 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7112,9 +7112,9 @@ static bool reexecute_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
if (vcpu->arch.mmu->direct_map) {
unsigned int indirect_shadow_pages;
- spin_lock(&vcpu->kvm->mmu_lock);
+ write_lock(&vcpu->kvm->mmu_lock);
indirect_shadow_pages = vcpu->kvm->arch.indirect_shadow_pages;
- spin_unlock(&vcpu->kvm->mmu_lock);
+ write_unlock(&vcpu->kvm->mmu_lock);
if (indirect_shadow_pages)
kvm_mmu_unprotect_page(vcpu->kvm, gpa_to_gfn(gpa));