1 files changed, 24 insertions, 6 deletions

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index b2d448c75008..76cf48051eb3 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -118,6 +118,9 @@ module_param_cb(h_ipi_redirect, &module_param_ops, &h_ipi_redirect,
 MODULE_PARM_DESC(h_ipi_redirect, "Redirect H_IPI wakeup to a free host core");
 #endif
 
+/* If set, the threads on each CPU core have to be in the same MMU mode */
+static bool no_mixing_hpt_and_radix;
+
 static void kvmppc_end_cede(struct kvm_vcpu *vcpu);
 static int kvmppc_hv_setup_htab_rma(struct kvm_vcpu *vcpu);
 
@@ -2386,8 +2389,8 @@ static void init_core_info(struct core_info *cip, struct kvmppc_vcore *vc)
 static bool subcore_config_ok(int n_subcores, int n_threads)
 {
 	/*
-	 * POWER9 "SMT4" cores are permanently in what is effectively a 4-way split-core
-	 * mode, with one thread per subcore.
+	 * POWER9 "SMT4" cores are permanently in what is effectively a 4-way
+	 * split-core mode, with one thread per subcore.
 	 */
 	if (cpu_has_feature(CPU_FTR_ARCH_300))
 		return n_subcores <= 4 && n_threads == 1;
@@ -2423,8 +2426,8 @@ static bool can_dynamic_split(struct kvmppc_vcore *vc, struct core_info *cip)
 	if (!cpu_has_feature(CPU_FTR_ARCH_207S))
 		return false;
 
-	/* POWER9 currently requires all threads to be in the same MMU mode */
-	if (cpu_has_feature(CPU_FTR_ARCH_300) &&
+	/* Some POWER9 chips require all threads to be in the same MMU mode */
+	if (no_mixing_hpt_and_radix &&
 	    kvm_is_radix(vc->kvm) != kvm_is_radix(cip->vc[0]->kvm))
 		return false;
 
@@ -2687,9 +2690,11 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc)
 	 * threads are offline.  Also check if the number of threads in this
 	 * guest are greater than the current system threads per guest.
 	 * On POWER9, we need to be not in independent-threads mode if
-	 * this is a HPT guest on a radix host.
+	 * this is a HPT guest on a radix host machine where the
+	 * CPU threads may not be in different MMU modes.
 	 */
-	hpt_on_radix = radix_enabled() && !kvm_is_radix(vc->kvm);
+	hpt_on_radix = no_mixing_hpt_and_radix && radix_enabled() &&
+		!kvm_is_radix(vc->kvm);
 	if (((controlled_threads > 1) &&
 	     ((vc->num_threads > threads_per_subcore) || !on_primary_thread())) ||
 	    (hpt_on_radix && vc->kvm->arch.threads_indep)) {
@@ -4446,6 +4451,19 @@ static int kvmppc_book3s_init_hv(void)
 
 	if (kvmppc_radix_possible())
 		r = kvmppc_radix_init();
+
+	/*
+	 * POWER9 chips before version 2.02 can't have some threads in
+	 * HPT mode and some in radix mode on the same core.
+	 */
+	if (cpu_has_feature(CPU_FTR_ARCH_300)) {
+		unsigned int pvr = mfspr(SPRN_PVR);
+		if ((pvr >> 16) == PVR_POWER9 &&
+		    (((pvr & 0xe000) == 0 && (pvr & 0xfff) < 0x202) ||
+		     ((pvr & 0xe000) == 0x2000 && (pvr & 0xfff) < 0x101)))
+			no_mixing_hpt_and_radix = true;
+	}
+
 	return r;
 }