KVM: PPC: Book3S PR: Take SRCU read lock around RTAS kvm_read_guest() call

This does for PR KVM what c9438092ca ("KVM: PPC: Book3S HV: Take SRCU
read lock around kvm_read_guest() call") did for HV KVM, that is,
eliminate a "suspicious rcu_dereference_check() usage!" warning by
taking the SRCU lock around the call to kvmppc_rtas_hcall().

It also fixes a return of RESUME_HOST to return EMULATE_FAIL instead,
since kvmppc_h_pr() is supposed to return EMULATE_* values.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Cc: stable@vger.kernel.org
Signed-off-by: Alexander Graf <agraf@suse.de>
This commit is contained in:
Paul Mackerras 2014-07-19 17:59:35 +10:00 committed by Alexander Graf
parent a0840240c0
commit ef1af2e296

View file

@ -267,6 +267,8 @@ static int kvmppc_h_pr_xics_hcall(struct kvm_vcpu *vcpu, u32 cmd)
int kvmppc_h_pr(struct kvm_vcpu *vcpu, unsigned long cmd)
{
int rc, idx;
if (cmd <= MAX_HCALL_OPCODE &&
!test_bit(cmd/4, vcpu->kvm->arch.enabled_hcalls))
return EMULATE_FAIL;
@ -299,8 +301,11 @@ int kvmppc_h_pr(struct kvm_vcpu *vcpu, unsigned long cmd)
break;
case H_RTAS:
if (list_empty(&vcpu->kvm->arch.rtas_tokens))
return RESUME_HOST;
if (kvmppc_rtas_hcall(vcpu))
break;
idx = srcu_read_lock(&vcpu->kvm->srcu);
rc = kvmppc_rtas_hcall(vcpu);
srcu_read_unlock(&vcpu->kvm->srcu, idx);
if (rc)
break;
kvmppc_set_gpr(vcpu, 3, 0);
return EMULATE_DONE;