Merge remote-tracking branch 'remotes/powerpc/topic/ppc-kvm' into kvm-ppc-next

This merges in the "ppc-kvm" topic branch of the powerpc tree to get a
series of commits that touch both general arch/powerpc code and KVM
code.  These commits will be merged both via the KVM tree and the
powerpc tree.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

arch/powerpc/include/asm/kvm_ppc.h

@@ -143,6 +143,7 @@ extern void kvmppc_core_vcpu_put(struct kvm_vcpu *vcpu);
 
 extern int kvmppc_core_prepare_to_enter(struct kvm_vcpu *vcpu);
 extern int kvmppc_core_pending_dec(struct kvm_vcpu *vcpu);
+extern void kvmppc_core_queue_machine_check(struct kvm_vcpu *vcpu, ulong flags);
 extern void kvmppc_core_queue_program(struct kvm_vcpu *vcpu, ulong flags);
 extern void kvmppc_core_queue_fpunavail(struct kvm_vcpu *vcpu);
 extern void kvmppc_core_queue_vec_unavail(struct kvm_vcpu *vcpu);
@@ -646,7 +647,7 @@ long int kvmppc_rm_h_confer(struct kvm_vcpu *vcpu, int target,
                             unsigned int yield_count);
 long kvmppc_h_random(struct kvm_vcpu *vcpu);
 void kvmhv_commence_exit(int trap);
-long kvmppc_realmode_machine_check(struct kvm_vcpu *vcpu);
+void kvmppc_realmode_machine_check(struct kvm_vcpu *vcpu);
 void kvmppc_subcore_enter_guest(void);
 void kvmppc_subcore_exit_guest(void);
 long kvmppc_realmode_hmi_handler(void);

arch/powerpc/include/asm/mce.h

@@ -209,7 +209,7 @@ extern int get_mce_event(struct machine_check_event *mce, bool release);
 extern void release_mce_event(void);
 extern void machine_check_queue_event(void);
 extern void machine_check_print_event_info(struct machine_check_event *evt,
-					   bool user_mode);
+					   bool user_mode, bool in_guest);
 #ifdef CONFIG_PPC_BOOK3S_64
 void flush_and_reload_slb(void);
 #endif /* CONFIG_PPC_BOOK3S_64 */

arch/powerpc/kernel/mce.c

@@ -301,13 +301,13 @@ static void machine_check_process_queued_event(struct irq_work *work)
 	while (__this_cpu_read(mce_queue_count) > 0) {
 		index = __this_cpu_read(mce_queue_count) - 1;
 		evt = this_cpu_ptr(&mce_event_queue[index]);
-		machine_check_print_event_info(evt, false);
+		machine_check_print_event_info(evt, false, false);
 		__this_cpu_dec(mce_queue_count);
 	}
 }
 
 void machine_check_print_event_info(struct machine_check_event *evt,
-				    bool user_mode)
+				    bool user_mode, bool in_guest)
 {
 	const char *level, *sevstr, *subtype;
 	static const char *mc_ue_types[] = {
@@ -387,7 +387,9 @@ void machine_check_print_event_info(struct machine_check_event *evt,
 	       evt->disposition == MCE_DISPOSITION_RECOVERED ?
 	       "Recovered" : "Not recovered");
 
-	if (user_mode) {
+	if (in_guest) {
+		printk("%s  Guest NIP: %016llx\n", level, evt->srr0);
+	} else if (user_mode) {
 		printk("%s  NIP: [%016llx] PID: %d Comm: %s\n", level,
 			evt->srr0, current->pid, current->comm);
 	} else {

arch/powerpc/kvm/book3s.c

@@ -195,6 +195,13 @@ void kvmppc_book3s_queue_irqprio(struct kvm_vcpu *vcpu, unsigned int vec)
 }
 EXPORT_SYMBOL_GPL(kvmppc_book3s_queue_irqprio);
 
+void kvmppc_core_queue_machine_check(struct kvm_vcpu *vcpu, ulong flags)
+{
+	/* might as well deliver this straight away */
+	kvmppc_inject_interrupt(vcpu, BOOK3S_INTERRUPT_MACHINE_CHECK, flags);
+}
+EXPORT_SYMBOL_GPL(kvmppc_core_queue_machine_check);
+
 void kvmppc_core_queue_program(struct kvm_vcpu *vcpu, ulong flags)
 {
 	/* might as well deliver this straight away */

arch/powerpc/kvm/book3s_hv.c

@@ -1217,6 +1217,22 @@ static int kvmppc_handle_exit_hv(struct kvm_run *run, struct kvm_vcpu *vcpu,
 		r = RESUME_GUEST;
 		break;
 	case BOOK3S_INTERRUPT_MACHINE_CHECK:
+		/* Print the MCE event to host console. */
+		machine_check_print_event_info(&vcpu->arch.mce_evt, false, true);
+
+		/*
+		 * If the guest can do FWNMI, exit to userspace so it can
+		 * deliver a FWNMI to the guest.
+		 * Otherwise we synthesize a machine check for the guest
+		 * so that it knows that the machine check occurred.
+		 */
+		if (!vcpu->kvm->arch.fwnmi_enabled) {
+			ulong flags = vcpu->arch.shregs.msr & 0x083c0000;
+			kvmppc_core_queue_machine_check(vcpu, flags);
+			r = RESUME_GUEST;
+			break;
+		}
+
 		/* Exit to guest with KVM_EXIT_NMI as exit reason */
 		run->exit_reason = KVM_EXIT_NMI;
 		run->hw.hardware_exit_reason = vcpu->arch.trap;
@@ -1229,8 +1245,6 @@ static int kvmppc_handle_exit_hv(struct kvm_run *run, struct kvm_vcpu *vcpu,
 			run->flags |= KVM_RUN_PPC_NMI_DISP_NOT_RECOV;
 
 		r = RESUME_HOST;
-		/* Print the MCE event to host console. */
-		machine_check_print_event_info(&vcpu->arch.mce_evt, false);
 		break;
 	case BOOK3S_INTERRUPT_PROGRAM:
 	{
@@ -1394,7 +1408,7 @@ static int kvmppc_handle_nested_exit(struct kvm_run *run, struct kvm_vcpu *vcpu)
 		/* Pass the machine check to the L1 guest */
 		r = RESUME_HOST;
 		/* Print the MCE event to host console. */
-		machine_check_print_event_info(&vcpu->arch.mce_evt, false);
+		machine_check_print_event_info(&vcpu->arch.mce_evt, false, true);
 		break;
 	/*
 	 * We get these next two if the guest accesses a page which it thinks
@@ -3457,6 +3471,7 @@ int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 	unsigned long host_dscr = mfspr(SPRN_DSCR);
 	unsigned long host_tidr = mfspr(SPRN_TIDR);
 	unsigned long host_iamr = mfspr(SPRN_IAMR);
+	unsigned long host_amr = mfspr(SPRN_AMR);
 	s64 dec;
 	u64 tb;
 	int trap, save_pmu;
@@ -3573,13 +3588,15 @@ int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	mtspr(SPRN_PSPB, 0);
 	mtspr(SPRN_WORT, 0);
-	mtspr(SPRN_AMR, 0);
 	mtspr(SPRN_UAMOR, 0);
 	mtspr(SPRN_DSCR, host_dscr);
 	mtspr(SPRN_TIDR, host_tidr);
 	mtspr(SPRN_IAMR, host_iamr);
 	mtspr(SPRN_PSPB, 0);
 
+	if (host_amr != vcpu->arch.amr)
+		mtspr(SPRN_AMR, host_amr);
+
 	msr_check_and_set(MSR_FP | MSR_VEC | MSR_VSX);
 	store_fp_state(&vcpu->arch.fp);
 #ifdef CONFIG_ALTIVEC

arch/powerpc/kvm/book3s_hv_ras.c

@@ -66,10 +66,8 @@ static void reload_slb(struct kvm_vcpu *vcpu)
 /*
  * On POWER7, see if we can handle a machine check that occurred inside
  * the guest in real mode, without switching to the host partition.
- *
- * Returns: 0 => exit guest, 1 => deliver machine check to guest
  */
-static long kvmppc_realmode_mc_power7(struct kvm_vcpu *vcpu)
+static void kvmppc_realmode_mc_power7(struct kvm_vcpu *vcpu)
 {
 	unsigned long srr1 = vcpu->arch.shregs.msr;
 	struct machine_check_event mce_evt;
@@ -111,52 +109,24 @@ static long kvmppc_realmode_mc_power7(struct kvm_vcpu *vcpu)
 	}
 
 	/*
-	 * See if we have already handled the condition in the linux host.
-	 * We assume that if the condition is recovered then linux host
-	 * will have generated an error log event that we will pick
-	 * up and log later.
-	 * Don't release mce event now. We will queue up the event so that
-	 * we can log the MCE event info on host console.
+	 * Now get the event and stash it in the vcpu struct so it can
+	 * be handled by the primary thread in virtual mode.  We can't
+	 * call machine_check_queue_event() here if we are running on
+	 * an offline secondary thread.
 	 */
-	if (!get_mce_event(&mce_evt, MCE_EVENT_DONTRELEASE))
-		goto out;
-
-	if (mce_evt.version == MCE_V1 &&
-	    (mce_evt.severity == MCE_SEV_NO_ERROR ||
-	     mce_evt.disposition == MCE_DISPOSITION_RECOVERED))
-		handled = 1;
-
-out:
-	/*
-	 * For guest that supports FWNMI capability, hook the MCE event into
-	 * vcpu structure. We are going to exit the guest with KVM_EXIT_NMI
-	 * exit reason. On our way to exit we will pull this event from vcpu
-	 * structure and print it from thread 0 of the core/subcore.
-	 *
-	 * For guest that does not support FWNMI capability (old QEMU):
-	 * We are now going enter guest either through machine check
-	 * interrupt (for unhandled errors) or will continue from
-	 * current HSRR0 (for handled errors) in guest. Hence
-	 * queue up the event so that we can log it from host console later.
-	 */
-	if (vcpu->kvm->arch.fwnmi_enabled) {
-		/*
-		 * Hook up the mce event on to vcpu structure.
-		 * First clear the old event.
-		 */
-		memset(&vcpu->arch.mce_evt, 0, sizeof(vcpu->arch.mce_evt));
-		if (get_mce_event(&mce_evt, MCE_EVENT_RELEASE)) {
-			vcpu->arch.mce_evt = mce_evt;
-		}
-	} else
-		machine_check_queue_event();
+	if (get_mce_event(&mce_evt, MCE_EVENT_RELEASE)) {
+		if (handled && mce_evt.version == MCE_V1)
+			mce_evt.disposition = MCE_DISPOSITION_RECOVERED;
+	} else {
+		memset(&mce_evt, 0, sizeof(mce_evt));
+	}
 
-	return handled;
+	vcpu->arch.mce_evt = mce_evt;
 }
 
-long kvmppc_realmode_machine_check(struct kvm_vcpu *vcpu)
+void kvmppc_realmode_machine_check(struct kvm_vcpu *vcpu)
 {
-	return kvmppc_realmode_mc_power7(vcpu);
+	kvmppc_realmode_mc_power7(vcpu);
 }
 
 /* Check if dynamic split is in force and return subcore size accordingly. */

arch/powerpc/kvm/book3s_hv_rmhandlers.S

@@ -58,6 +58,8 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
 #define STACK_SLOT_DAWR		(SFS-56)
 #define STACK_SLOT_DAWRX	(SFS-64)
 #define STACK_SLOT_HFSCR	(SFS-72)
+#define STACK_SLOT_AMR		(SFS-80)
+#define STACK_SLOT_UAMOR	(SFS-88)
 /* the following is used by the P9 short path */
 #define STACK_SLOT_NVGPRS	(SFS-152)	/* 18 gprs */
 
@@ -726,11 +728,9 @@ BEGIN_FTR_SECTION
 	mfspr	r5, SPRN_TIDR
 	mfspr	r6, SPRN_PSSCR
 	mfspr	r7, SPRN_PID
-	mfspr	r8, SPRN_IAMR
 	std	r5, STACK_SLOT_TID(r1)
 	std	r6, STACK_SLOT_PSSCR(r1)
 	std	r7, STACK_SLOT_PID(r1)
-	std	r8, STACK_SLOT_IAMR(r1)
 	mfspr	r5, SPRN_HFSCR
 	std	r5, STACK_SLOT_HFSCR(r1)
 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
@@ -738,11 +738,18 @@ BEGIN_FTR_SECTION
 	mfspr	r5, SPRN_CIABR
 	mfspr	r6, SPRN_DAWR
 	mfspr	r7, SPRN_DAWRX
+	mfspr	r8, SPRN_IAMR
 	std	r5, STACK_SLOT_CIABR(r1)
 	std	r6, STACK_SLOT_DAWR(r1)
 	std	r7, STACK_SLOT_DAWRX(r1)
+	std	r8, STACK_SLOT_IAMR(r1)
 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
 
+	mfspr	r5, SPRN_AMR
+	std	r5, STACK_SLOT_AMR(r1)
+	mfspr	r6, SPRN_UAMOR
+	std	r6, STACK_SLOT_UAMOR(r1)
+
 BEGIN_FTR_SECTION
 	/* Set partition DABR */
 	/* Do this before re-enabling PMU to avoid P7 DABR corruption bug */
@@ -1631,22 +1638,25 @@ ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_300)
 	mtspr	SPRN_PSPB, r0
 	mtspr	SPRN_WORT, r0
 BEGIN_FTR_SECTION
-	mtspr	SPRN_IAMR, r0
 	mtspr	SPRN_TCSCR, r0
 	/* Set MMCRS to 1<<31 to freeze and disable the SPMC counters */
 	li	r0, 1
 	sldi	r0, r0, 31
 	mtspr	SPRN_MMCRS, r0
 END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
-8:
 
-	/* Save and reset AMR and UAMOR before turning on the MMU */
+	/* Save and restore AMR, IAMR and UAMOR before turning on the MMU */
+	ld	r8, STACK_SLOT_IAMR(r1)
+	mtspr	SPRN_IAMR, r8
+
+8:	/* Power7 jumps back in here */
 	mfspr	r5,SPRN_AMR
 	mfspr	r6,SPRN_UAMOR
 	std	r5,VCPU_AMR(r9)
 	std	r6,VCPU_UAMOR(r9)
-	li	r6,0
-	mtspr	SPRN_AMR,r6
+	ld	r5,STACK_SLOT_AMR(r1)
+	ld	r6,STACK_SLOT_UAMOR(r1)
+	mtspr	SPRN_AMR, r5
 	mtspr	SPRN_UAMOR, r6
 
 	/* Switch DSCR back to host value */
@@ -1746,11 +1756,9 @@ BEGIN_FTR_SECTION
 	ld	r5, STACK_SLOT_TID(r1)
 	ld	r6, STACK_SLOT_PSSCR(r1)
 	ld	r7, STACK_SLOT_PID(r1)
-	ld	r8, STACK_SLOT_IAMR(r1)
 	mtspr	SPRN_TIDR, r5
 	mtspr	SPRN_PSSCR, r6
 	mtspr	SPRN_PID, r7
-	mtspr	SPRN_IAMR, r8
 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
 
 #ifdef CONFIG_PPC_RADIX_MMU
@@ -2836,49 +2844,15 @@ kvm_cede_exit:
 #endif /* CONFIG_KVM_XICS */
 3:	b	guest_exit_cont
 
-	/* Try to handle a machine check in real mode */
+	/* Try to do machine check recovery in real mode */
 machine_check_realmode:
 	mr	r3, r9		/* get vcpu pointer */
 	bl	kvmppc_realmode_machine_check
 	nop
+	/* all machine checks go to virtual mode for further handling */
 	ld	r9, HSTATE_KVM_VCPU(r13)
 	li	r12, BOOK3S_INTERRUPT_MACHINE_CHECK
-	/*
-	 * For the guest that is FWNMI capable, deliver all the MCE errors
-	 * (handled/unhandled) by exiting the guest with KVM_EXIT_NMI exit
-	 * reason. This new approach injects machine check errors in guest
-	 * address space to guest with additional information in the form
-	 * of RTAS event, thus enabling guest kernel to suitably handle
-	 * such errors.
-	 *
-	 * For the guest that is not FWNMI capable (old QEMU) fallback
-	 * to old behaviour for backward compatibility:
-	 * Deliver unhandled/fatal (e.g. UE) MCE errors to guest either
-	 * through machine check interrupt (set HSRR0 to 0x200).
-	 * For handled errors (no-fatal), just go back to guest execution
-	 * with current HSRR0.
-	 * if we receive machine check with MSR(RI=0) then deliver it to
-	 * guest as machine check causing guest to crash.
-	 */
-	ld	r11, VCPU_MSR(r9)
-	rldicl.	r0, r11, 64-MSR_HV_LG, 63 /* check if it happened in HV mode */
-	bne	guest_exit_cont		/* if so, exit to host */
-	/* Check if guest is capable of handling NMI exit */
-	ld	r10, VCPU_KVM(r9)
-	lbz	r10, KVM_FWNMI(r10)
-	cmpdi	r10, 1			/* FWNMI capable? */
-	beq	guest_exit_cont		/* if so, exit with KVM_EXIT_NMI. */
-
-	/* if not, fall through for backward compatibility. */
-	andi.	r10, r11, MSR_RI	/* check for unrecoverable exception */
-	beq	1f			/* Deliver a machine check to guest */
-	ld	r10, VCPU_PC(r9)
-	cmpdi	r3, 0		/* Did we handle MCE ? */
-	bne	2f	/* Continue guest execution. */
-	/* If not, deliver a machine check.  SRR0/1 are already set */
-1:	li	r10, BOOK3S_INTERRUPT_MACHINE_CHECK
-	bl	kvmppc_msr_interrupt
-2:	b	fast_interrupt_c_return
+	b	guest_exit_cont
 
 /*
  * Call C code to handle a HMI in real mode.

arch/powerpc/platforms/powernv/opal.c

@@ -587,7 +587,7 @@ int opal_machine_check(struct pt_regs *regs)
 		       evt.version);
 		return 0;
 	}
-	machine_check_print_event_info(&evt, user_mode(regs));
+	machine_check_print_event_info(&evt, user_mode(regs), false);
 
 	if (opal_recover_mce(regs, &evt))
 		return 1;