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From: Thomas Huth <thuth@redhat.com>
To: kvm-ppc@vger.kernel.org, Paul Mackerras <paulus@samba.org>,
	Alexander Graf <agraf@suse.com>
Cc: kvm@vger.kernel.org, David Gibson <david@gibson.dropbear.id.au>
Subject: [PATCH] KVM: PPC: Take the kvm->srcu lock in kvmppc_h_logical_ci_load/store()
Date: Fri, 18 Sep 2015 08:57:28 +0200	[thread overview]
Message-ID: <1442559448-1947-1-git-send-email-thuth@redhat.com> (raw)

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 <thuth@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


WARNING: multiple messages have this Message-ID (diff)
From: Thomas Huth <thuth@redhat.com>
To: kvm-ppc@vger.kernel.org, Paul Mackerras <paulus@samba.org>,
	Alexander Graf <agraf@suse.com>
Cc: kvm@vger.kernel.org, David Gibson <david@gibson.dropbear.id.au>
Subject: [PATCH] KVM: PPC: Take the kvm->srcu lock in kvmppc_h_logical_ci_load/store()
Date: Fri, 18 Sep 2015 06:57:28 +0000	[thread overview]
Message-ID: <1442559448-1947-1-git-send-email-thuth@redhat.com> (raw)

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 <thuth@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


             reply	other threads:[~2015-09-18  6:57 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-09-18  6:57 Thomas Huth [this message]
2015-09-18  6:57 ` [PATCH] KVM: PPC: Take the kvm->srcu lock in kvmppc_h_logical_ci_load/store() Thomas Huth
2015-09-21  1:37 ` David Gibson
2015-09-21  1:37   ` David Gibson
2015-09-21  5:50   ` Paolo Bonzini
2015-09-21  5:50     ` Paolo Bonzini
2015-09-21  7:59     ` Paul Mackerras
2015-09-21  7:59       ` Paul Mackerras
2015-09-21  9:30       ` Paolo Bonzini
2015-09-21  9:30         ` Paolo Bonzini
2015-09-21  6:50   ` Thomas Huth
2015-09-21  6:50     ` Thomas Huth

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