Third PPC KVM update for 5.1

- Tell userspace about whether a particular hardware workaround for
   one of the Spectre vulnerabilities is available, so that userspace
   can inform the guest.
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Merge tag 'kvm-ppc-next-5.1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into HEAD

Third PPC KVM update for 5.1

- Tell userspace about whether a particular hardware workaround for
  one of the Spectre vulnerabilities is available, so that userspace
  can inform the guest.

arch/powerpc/include/asm/kvm_ppc.h

@@ -619,7 +619,7 @@ static inline int kvmppc_xive_set_irq(struct kvm *kvm, int irq_source_id, u32 ir
 static inline void kvmppc_xive_push_vcpu(struct kvm_vcpu *vcpu) { }
 #endif /* CONFIG_KVM_XIVE */
 
-#ifdef CONFIG_PPC_POWERNV
+#if defined(CONFIG_PPC_POWERNV) && defined(CONFIG_KVM_BOOK3S_64_HANDLER)
 static inline bool xics_on_xive(void)
 {
 	return xive_enabled() && cpu_has_feature(CPU_FTR_HVMODE);

arch/powerpc/include/uapi/asm/kvm.h

@@ -463,10 +463,12 @@ struct kvm_ppc_cpu_char {
 #define KVM_PPC_CPU_CHAR_BR_HINT_HONOURED	(1ULL << 58)
 #define KVM_PPC_CPU_CHAR_MTTRIG_THR_RECONF	(1ULL << 57)
 #define KVM_PPC_CPU_CHAR_COUNT_CACHE_DIS	(1ULL << 56)
+#define KVM_PPC_CPU_CHAR_BCCTR_FLUSH_ASSIST	(1ull << 54)
 
 #define KVM_PPC_CPU_BEHAV_FAVOUR_SECURITY	(1ULL << 63)
 #define KVM_PPC_CPU_BEHAV_L1D_FLUSH_PR		(1ULL << 62)
 #define KVM_PPC_CPU_BEHAV_BNDS_CHK_SPEC_BAR	(1ULL << 61)
+#define KVM_PPC_CPU_BEHAV_FLUSH_COUNT_CACHE	(1ull << 58)
 
 /* Per-vcpu XICS interrupt controller state */
 #define KVM_REG_PPC_ICP_STATE	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0x8c)

arch/powerpc/kvm/powerpc.c

@@ -2189,10 +2189,12 @@ static int pseries_get_cpu_char(struct kvm_ppc_cpu_char *cp)
 			KVM_PPC_CPU_CHAR_L1D_THREAD_PRIV |
 			KVM_PPC_CPU_CHAR_BR_HINT_HONOURED |
 			KVM_PPC_CPU_CHAR_MTTRIG_THR_RECONF |
-			KVM_PPC_CPU_CHAR_COUNT_CACHE_DIS;
+			KVM_PPC_CPU_CHAR_COUNT_CACHE_DIS |
+			KVM_PPC_CPU_CHAR_BCCTR_FLUSH_ASSIST;
 		cp->behaviour_mask = KVM_PPC_CPU_BEHAV_FAVOUR_SECURITY |
 			KVM_PPC_CPU_BEHAV_L1D_FLUSH_PR |
-			KVM_PPC_CPU_BEHAV_BNDS_CHK_SPEC_BAR;
+			KVM_PPC_CPU_BEHAV_BNDS_CHK_SPEC_BAR |
+			KVM_PPC_CPU_BEHAV_FLUSH_COUNT_CACHE;
 	}
 	return 0;
 }
@@ -2251,12 +2253,16 @@ static int kvmppc_get_cpu_char(struct kvm_ppc_cpu_char *cp)
 		if (have_fw_feat(fw_features, "enabled",
 				 "fw-count-cache-disabled"))
 			cp->character |= KVM_PPC_CPU_CHAR_COUNT_CACHE_DIS;
+		if (have_fw_feat(fw_features, "enabled",
+				 "fw-count-cache-flush-bcctr2,0,0"))
+			cp->character |= KVM_PPC_CPU_CHAR_BCCTR_FLUSH_ASSIST;
 		cp->character_mask = KVM_PPC_CPU_CHAR_SPEC_BAR_ORI31 |
 			KVM_PPC_CPU_CHAR_BCCTRL_SERIALISED |
 			KVM_PPC_CPU_CHAR_L1D_FLUSH_ORI30 |
 			KVM_PPC_CPU_CHAR_L1D_FLUSH_TRIG2 |
 			KVM_PPC_CPU_CHAR_L1D_THREAD_PRIV |
-			KVM_PPC_CPU_CHAR_COUNT_CACHE_DIS;
+			KVM_PPC_CPU_CHAR_COUNT_CACHE_DIS |
+			KVM_PPC_CPU_CHAR_BCCTR_FLUSH_ASSIST;
 
 		if (have_fw_feat(fw_features, "enabled",
 				 "speculation-policy-favor-security"))
@@ -2267,9 +2273,13 @@ static int kvmppc_get_cpu_char(struct kvm_ppc_cpu_char *cp)
 		if (!have_fw_feat(fw_features, "disabled",
 				  "needs-spec-barrier-for-bound-checks"))
 			cp->behaviour |= KVM_PPC_CPU_BEHAV_BNDS_CHK_SPEC_BAR;
+		if (have_fw_feat(fw_features, "enabled",
+				 "needs-count-cache-flush-on-context-switch"))
+			cp->behaviour |= KVM_PPC_CPU_BEHAV_FLUSH_COUNT_CACHE;
 		cp->behaviour_mask = KVM_PPC_CPU_BEHAV_FAVOUR_SECURITY |
 			KVM_PPC_CPU_BEHAV_L1D_FLUSH_PR |
-			KVM_PPC_CPU_BEHAV_BNDS_CHK_SPEC_BAR;
+			KVM_PPC_CPU_BEHAV_BNDS_CHK_SPEC_BAR |
+			KVM_PPC_CPU_BEHAV_FLUSH_COUNT_CACHE;
 
 		of_node_put(fw_features);
 	}