From ef1af2e29622ff3403926ae801a2b10da075a2de Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Sat, 19 Jul 2014 17:59:35 +1000 Subject: [PATCH] KVM: PPC: Book3S PR: Take SRCU read lock around RTAS kvm_read_guest() call This does for PR KVM what c9438092cae4 ("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 Cc: stable@vger.kernel.org Signed-off-by: Alexander Graf --- arch/powerpc/kvm/book3s_pr_papr.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/kvm/book3s_pr_papr.c b/arch/powerpc/kvm/book3s_pr_papr.c index 6d0143fbeb63..ce3c893d509b 100644 --- a/arch/powerpc/kvm/book3s_pr_papr.c +++ b/arch/powerpc/kvm/book3s_pr_papr.c @@ -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; -- 2.20.1