[PATCH] KVM: PPC: Take the kvm->srcu lock in kvmppc_h_logical_ci_load/store()

[Thomas Huth]

Access to the kvm->buses (like with the kvm_io_bus_read() and -write()
functions) has to be protected via the kvm->srcu lock.
The kvmppc_h_logical_ci_load() and -store() functions are missing
this lock so far, so let's add it there, too.
This fixes the problem that the kernel reports "suspicious RCU usage"
when lock debugging is enabled.

Fixes: 99342cf8044420eebdf9297ca03a14cb6a7085a1
Signed-off-by: Thomas Huth <th...@redhat.com>
---
 arch/powerpc/kvm/book3s.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index d75bf32..096e5eb 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -828,12 +828,15 @@ int kvmppc_h_logical_ci_load(struct kvm_vcpu *vcpu)
        unsigned long size = kvmppc_get_gpr(vcpu, 4);
        unsigned long addr = kvmppc_get_gpr(vcpu, 5);
        u64 buf;
+       int srcu_idx;
        int ret;
 
        if (!is_power_of_2(size) || (size > sizeof(buf)))
                return H_TOO_HARD;
 
+       srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
        ret = kvm_io_bus_read(vcpu, KVM_MMIO_BUS, addr, size, &buf);
+       srcu_read_unlock(&vcpu->kvm->srcu, srcu_idx);
        if (ret != 0)
                return H_TOO_HARD;
 
@@ -868,6 +871,7 @@ int kvmppc_h_logical_ci_store(struct kvm_vcpu *vcpu)
        unsigned long addr = kvmppc_get_gpr(vcpu, 5);
        unsigned long val = kvmppc_get_gpr(vcpu, 6);
        u64 buf;
+       int srcu_idx;
        int ret;
 
        switch (size) {
@@ -891,7 +895,9 @@ int kvmppc_h_logical_ci_store(struct kvm_vcpu *vcpu)
                return H_TOO_HARD;
        }
 
+       srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
        ret = kvm_io_bus_write(vcpu, KVM_MMIO_BUS, addr, size, &buf);
+       srcu_read_unlock(&vcpu->kvm->srcu, srcu_idx);
        if (ret != 0)
                return H_TOO_HARD;
 
-- 
1.8.3.1

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