From: Nicholas Piggin Date: Mon, 12 Apr 2021 01:48:45 +0000 (+1000) Subject: KVM: PPC: Book3S HV: Ensure MSR[HV] is always clear in guest MSR X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=732f21a3053cf279eb6b85d19b7818a8f1dd2071;p=linux.git KVM: PPC: Book3S HV: Ensure MSR[HV] is always clear in guest MSR Rather than clear the HV bit from the MSR at guest entry, make it clear that the hypervisor does not allow the guest to set the bit. The HV clear is kept in guest entry for now, but a future patch will warn if it is set. Signed-off-by: Nicholas Piggin Acked-by: Paul Mackerras Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210412014845.1517916-13-npiggin@gmail.com --- diff --git a/arch/powerpc/kvm/book3s_hv_builtin.c b/arch/powerpc/kvm/book3s_hv_builtin.c index 41cb03d0bde45..7a0e33a9c980d 100644 --- a/arch/powerpc/kvm/book3s_hv_builtin.c +++ b/arch/powerpc/kvm/book3s_hv_builtin.c @@ -662,8 +662,8 @@ 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 ME enabled. */ - msr = msr | MSR_ME; + /* Guest must always run with ME enabled, HV disabled. */ + msr = (msr | MSR_ME) & ~MSR_HV; /* * Check for illegal transactional state bit combination diff --git a/arch/powerpc/kvm/book3s_hv_nested.c b/arch/powerpc/kvm/book3s_hv_nested.c index fb03085c902ba..60724f6744219 100644 --- a/arch/powerpc/kvm/book3s_hv_nested.c +++ b/arch/powerpc/kvm/book3s_hv_nested.c @@ -344,8 +344,8 @@ long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu) vcpu->arch.nested_vcpu_id = l2_hv.vcpu_token; vcpu->arch.regs = l2_regs; - /* Guest must always run with ME enabled. */ - vcpu->arch.shregs.msr = vcpu->arch.regs.msr | MSR_ME; + /* Guest must always run with ME enabled, HV disabled. */ + vcpu->arch.shregs.msr = (vcpu->arch.regs.msr | MSR_ME) & ~MSR_HV; sanitise_hv_regs(vcpu, &l2_hv); restore_hv_regs(vcpu, &l2_hv);