[PATCH v4 10/46] KVM: PPC: Book3S HV: Ensure MSR[ME] is always set in guest MSR
From: Nicholas Piggin <npiggin@gmail.com>
Date: 2021-03-23 01:08:02
Subsystem:
kernel virtual machine for powerpc (kvm/powerpc), linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
Rather than add the ME bit to the MSR at guest entry, make it clear that the hypervisor does not allow the guest to clear the bit. The ME set is kept in guest entry for now, but a future patch will warn if it's not present. Reviewed-by: Daniel Axtens <redacted> Reviewed-by: Fabiano Rosas <redacted> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> --- arch/powerpc/kvm/book3s_hv_builtin.c | 3 +++ arch/powerpc/kvm/book3s_hv_nested.c | 4 +++- 2 files changed, 6 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/kvm/book3s_hv_builtin.c b/arch/powerpc/kvm/book3s_hv_builtin.c
index 158d309b42a3..41cb03d0bde4 100644
--- a/arch/powerpc/kvm/book3s_hv_builtin.c
+++ b/arch/powerpc/kvm/book3s_hv_builtin.c@@ -662,6 +662,9 @@ 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; + /* * Check for illegal transactional state bit combination * and if we find it, force the TS field to a safe state.
diff --git a/arch/powerpc/kvm/book3s_hv_nested.c b/arch/powerpc/kvm/book3s_hv_nested.c
index 851e3f527eb2..886c7fa86add 100644
--- a/arch/powerpc/kvm/book3s_hv_nested.c
+++ b/arch/powerpc/kvm/book3s_hv_nested.c@@ -328,7 +328,9 @@ long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu) vcpu->arch.nested = l2; vcpu->arch.nested_vcpu_id = l2_hv.vcpu_token; vcpu->arch.regs = l2_regs; - vcpu->arch.shregs.msr = vcpu->arch.regs.msr; + + /* Guest must always run with ME enabled. */ + vcpu->arch.shregs.msr = vcpu->arch.regs.msr | MSR_ME; sanitise_hv_regs(vcpu, &l2_hv); restore_hv_regs(vcpu, &l2_hv);
--
2.23.0