| Message ID | 20191218051130.GA29890@oak.ozlabs.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: PPC: Book3S HV: Don't do ultravisor calls on systems without ultravisor | expand |
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index dc53578193ee..6ff3f896d908 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -4983,7 +4983,8 @@ static void kvmppc_core_destroy_vm_hv(struct kvm *kvm) if (nesting_enabled(kvm)) kvmhv_release_all_nested(kvm); kvm->arch.process_table = 0; - uv_svm_terminate(kvm->arch.lpid); + if (kvm->arch.secure_guest) + uv_svm_terminate(kvm->arch.lpid); kvmhv_set_ptbl_entry(kvm->arch.lpid, 0, 0); }
Commit 22945688acd4 ("KVM: PPC: Book3S HV: Support reset of secure guest") added a call to uv_svm_terminate, which is an ultravisor call, without any check that the guest is a secure guest or even that the system has an ultravisor. On a system without an ultravisor, the ultracall will degenerate to a hypercall, but since we are not in KVM guest context, the hypercall will get treated as a system call, which could have random effects depending on what happens to be in r0, and could also corrupt the current task's kernel stack. Hence this adds a test for the guest being a secure guest before doing uv_svm_terminate(). Fixes: 22945688acd4 ("KVM: PPC: Book3S HV: Support reset of secure guest") Signed-off-by: Paul Mackerras <paulus@ozlabs.org> --- arch/powerpc/kvm/book3s_hv.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)