From mboxrd@z Thu Jan 1 00:00:00 1970 From: Fabiano Rosas Date: Mon, 22 Feb 2021 22:23:20 +0000 Subject: Re: [PATCH 03/13] KVM: PPC: Book3S HV: Ensure MSR[ME] is always set in guest MSR Message-Id: <87h7m3yc6f.fsf@linux.ibm.com> List-Id: References: <20210219063542.1425130-1-npiggin@gmail.com> <20210219063542.1425130-4-npiggin@gmail.com> In-Reply-To: <20210219063542.1425130-4-npiggin@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Nicholas Piggin , kvm-ppc@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org, Nicholas Piggin Nicholas Piggin writes: > Rather than add the ME bit to the MSR when the guest is entered, make > it clear that the hypervisor does not allow the guest to clear the bit. > > The ME addition is kept in the code for now, but a future patch will > warn if it's not present. > > Signed-off-by: Nicholas Piggin Reviewed-by: Fabiano Rosas > --- > arch/powerpc/kvm/book3s_hv_builtin.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/arch/powerpc/kvm/book3s_hv_builtin.c b/arch/powerpc/kvm/book3s_hv_builtin.c > index dad118760a4e..ae8f291c5c48 100644 > --- a/arch/powerpc/kvm/book3s_hv_builtin.c > +++ b/arch/powerpc/kvm/book3s_hv_builtin.c > @@ -661,6 +661,13 @@ static void kvmppc_end_cede(struct kvm_vcpu *vcpu) > > void kvmppc_set_msr_hv(struct kvm_vcpu *vcpu, u64 msr) > { > + /* > + * Guest must always run with machine check interrupt > + * enabled. > + */ > + if (!(msr & MSR_ME)) > + msr |= MSR_ME; > + > /* > * Check for illegal transactional state bit combination > * and if we find it, force the TS field to a safe state.