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authorBen Gardon <bgardon@google.com>2021-02-02 10:57:29 -0800
committerPaolo Bonzini <pbonzini@redhat.com>2021-02-04 05:27:45 -0500
commita2855afc7ee88475e8feb16840b23f787bfc994d (patch)
treeb561f5b1dd44c92144d84e7e3215c26fc216cd76
parente25f0e0cd51bfb1e2e6121373c68f1427266bba7 (diff)
downloadlinux-a2855afc7ee88475e8feb16840b23f787bfc994d.tar.bz2
KVM: x86/mmu: Allow parallel page faults for the TDP MMU
Make the last few changes necessary to enable the TDP MMU to handle page faults in parallel while holding the mmu_lock in read mode. Reviewed-by: Peter Feiner <pfeiner@google.com> Signed-off-by: Ben Gardon <bgardon@google.com> Message-Id: <20210202185734.1680553-24-bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-rw-r--r--arch/x86/kvm/mmu/mmu.c12
1 files changed, 10 insertions, 2 deletions
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 329930d57774..e8bfff9acd5e 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -3718,7 +3718,12 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code,
return r;
r = RET_PF_RETRY;
- write_lock(&vcpu->kvm->mmu_lock);
+
+ if (is_tdp_mmu_root(vcpu->kvm, vcpu->arch.mmu->root_hpa))
+ read_lock(&vcpu->kvm->mmu_lock);
+ else
+ write_lock(&vcpu->kvm->mmu_lock);
+
if (mmu_notifier_retry(vcpu->kvm, mmu_seq))
goto out_unlock;
r = make_mmu_pages_available(vcpu);
@@ -3733,7 +3738,10 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code,
prefault, is_tdp);
out_unlock:
- write_unlock(&vcpu->kvm->mmu_lock);
+ if (is_tdp_mmu_root(vcpu->kvm, vcpu->arch.mmu->root_hpa))
+ read_unlock(&vcpu->kvm->mmu_lock);
+ else
+ write_unlock(&vcpu->kvm->mmu_lock);
kvm_release_pfn_clean(pfn);
return r;
}