3 files changed, 80 insertions, 64 deletions

diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index c9c67fc888c9..799322433620 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -290,6 +290,7 @@
 #define     LPCR_PECE1  0x00002000      /* decrementer can cause exit */
 #define     LPCR_PECE2  0x00001000      /* machine check etc can cause exit */
 #define   LPCR_MER      0x00000800      /* Mediated External Exception */
+#define   LPCR_MER_SH   11
 #define   LPCR_LPES    0x0000000c
 #define   LPCR_LPES0   0x00000008      /* LPAR Env selector 0 */
 #define   LPCR_LPES1   0x00000004      /* LPAR Env selector 1 */
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 16191915e8d0..178521e81ce4 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -1384,9 +1384,12 @@ static int kvmppc_run_vcpu(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
                         break;
                 vc->runner = vcpu;
                 n_ceded = 0;
-                list_for_each_entry(v, &vc->runnable_threads, arch.run_list)
+                list_for_each_entry(v, &vc->runnable_threads, arch.run_list) {
                         if (!v->arch.pending_exceptions)
                                 n_ceded += v->arch.ceded;
+                        else
+                                v->arch.ceded = 0;
+                }
                 if (n_ceded == vc->n_runnable)
                         kvmppc_vcore_blocked(vc);
                 else
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index fd3b72d5dfe6..b02f91e4c70d 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -97,50 +97,51 @@ kvm_start_guest:
         li      r0,1
         stb     r0,PACA_NAPSTATELOST(r13)
 
-        /* get vcpu pointer, NULL if we have no vcpu to run */
-        ld      r4,HSTATE_KVM_VCPU(r13)
-        cmpdi   cr1,r4,0
+        /* were we napping due to cede? */
+        lbz     r0,HSTATE_NAPPING(r13)
+        cmpwi   r0,0
+        bne     kvm_end_cede
+
+        /*
+         * We weren't napping due to cede, so this must be a secondary
+         * thread being woken up to run a guest, or being woken up due
+         * to a stray IPI.  (Or due to some machine check or hypervisor
+         * maintenance interrupt while the core is in KVM.)
+         */
 
         /* Check the wake reason in SRR1 to see why we got here */
         mfspr   r3,SPRN_SRR1
         rlwinm  r3,r3,44-31,0x7         /* extract wake reason field */
         cmpwi   r3,4                    /* was it an external interrupt? */
-        bne     27f
-
-        /*
-         * External interrupt - for now assume it is an IPI, since we
-         * should never get any other interrupts sent to offline threads.
-         * Only do this for secondary threads.
-         */
-        beq     cr1,25f
-        lwz     r3,VCPU_PTID(r4)
-        cmpwi   r3,0
-        beq     27f
-25:     ld      r5,HSTATE_XICS_PHYS(r13)
-        li      r0,0xff
-        li      r6,XICS_MFRR
-        li      r7,XICS_XIRR
+        bne     27f                     /* if not */
+        ld      r5,HSTATE_XICS_PHYS(r13)
+        li      r7,XICS_XIRR            /* if it was an external interrupt, */
         lwzcix  r8,r5,r7                /* get and ack the interrupt */
         sync
         clrldi. r9,r8,40                /* get interrupt source ID. */
-        beq     27f                     /* none there? */
-        cmpwi   r9,XICS_IPI
-        bne     26f
+        beq     28f                     /* none there? */
+        cmpwi   r9,XICS_IPI             /* was it an IPI? */
+        bne     29f
+        li      r0,0xff
+        li      r6,XICS_MFRR
         stbcix  r0,r5,r6                /* clear IPI */
-26:     stwcix  r8,r5,r7                /* EOI the interrupt */
+        stwcix  r8,r5,r7                /* EOI the interrupt */
+        sync                            /* order loading of vcpu after that */
 
-27:     /* XXX should handle hypervisor maintenance interrupts etc. here */
-
-        /* reload vcpu pointer after clearing the IPI */
+        /* get vcpu pointer, NULL if we have no vcpu to run */
         ld      r4,HSTATE_KVM_VCPU(r13)
         cmpdi   r4,0
         /* if we have no vcpu to run, go back to sleep */
         beq     kvm_no_guest
+        b       kvmppc_hv_entry
 
-        /* were we napping due to cede? */
-        lbz     r0,HSTATE_NAPPING(r13)
-        cmpwi   r0,0
-        bne     kvm_end_cede
+27:     /* XXX should handle hypervisor maintenance interrupts etc. here */
+        b       kvm_no_guest
+28:     /* SRR1 said external but ICP said nope?? */
+        b       kvm_no_guest
+29:     /* External non-IPI interrupt to offline secondary thread? help?? */
+        stw     r8,HSTATE_SAVED_XIRR(r13)
+        b       kvm_no_guest
 
 .global kvmppc_hv_entry
 kvmppc_hv_entry:
@@ -483,20 +484,20 @@ toc_tlbie_lock:
         mtctr   r6
         mtxer   r7
 
+        ld      r10, VCPU_PC(r4)
+        ld      r11, VCPU_MSR(r4)
 kvmppc_cede_reentry:            /* r4 = vcpu, r13 = paca */
         ld      r6, VCPU_SRR0(r4)
         ld      r7, VCPU_SRR1(r4)
-        ld      r10, VCPU_PC(r4)
-        ld      r11, VCPU_MSR(r4)       /* r11 = vcpu->arch.msr & ~MSR_HV */
 
+        /* r11 = vcpu->arch.msr & ~MSR_HV */
         rldicl  r11, r11, 63 - MSR_HV_LG, 1
         rotldi  r11, r11, 1 + MSR_HV_LG
         ori     r11, r11, MSR_ME
 
         /* Check if we can deliver an external or decrementer interrupt now */
         ld      r0,VCPU_PENDING_EXC(r4)
-        li      r8,(1 << BOOK3S_IRQPRIO_EXTERNAL)
-        oris    r8,r8,(1 << BOOK3S_IRQPRIO_EXTERNAL_LEVEL)@h
+        lis     r8,(1 << BOOK3S_IRQPRIO_EXTERNAL_LEVEL)@h
         and     r0,r0,r8
         cmpdi   cr1,r0,0
         andi.   r0,r11,MSR_EE
@@ -524,10 +525,10 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_206)
         /* Move SRR0 and SRR1 into the respective regs */
 5:      mtspr   SPRN_SRR0, r6
         mtspr   SPRN_SRR1, r7
-        li      r0,0
-        stb     r0,VCPU_CEDED(r4)       /* cancel cede */
 
 fast_guest_return:
+        li      r0,0
+        stb     r0,VCPU_CEDED(r4)       /* cancel cede */
         mtspr   SPRN_HSRR0,r10
         mtspr   SPRN_HSRR1,r11
 
@@ -686,6 +687,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_206)
         /* External interrupt, first check for host_ipi. If this is
          * set, we know the host wants us out so let's do it now
          */
+do_ext_interrupt:
         lbz     r0, HSTATE_HOST_IPI(r13)
         cmpwi   r0, 0
         bne     ext_interrupt_to_host
@@ -698,19 +700,9 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_206)
         lwzcix  r3, r5, r7
         rlwinm. r0, r3, 0, 0xffffff
         sync
-        bne     1f
+        beq     3f              /* if nothing pending in the ICP */
 
-        /* Nothing pending in the ICP, check for mediated interrupts
-         * and bounce it to the guest
-         */
-        andi.   r0, r11, MSR_EE
-        beq     ext_interrupt_to_host /* shouldn't happen ?? */
-        mfspr   r5, SPRN_LPCR
-        andi.   r0, r5, LPCR_MER
-        bne     bounce_ext_interrupt
-        b       ext_interrupt_to_host /* shouldn't happen ?? */
-
-1:      /* We found something in the ICP...
+        /* We found something in the ICP...
          *
          * If it's not an IPI, stash it in the PACA and return to
          * the host, we don't (yet) handle directing real external
@@ -735,16 +727,33 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_206)
         bne-    1f
 
         /* Allright, looks like an IPI for the guest, we need to set MER */
-        mfspr   r8,SPRN_LPCR
-        ori     r8,r8,LPCR_MER
-        mtspr   SPRN_LPCR,r8
+3:
+        /* Check if any CPU is heading out to the host, if so head out too */
+        ld      r5, HSTATE_KVM_VCORE(r13)
+        lwz     r0, VCORE_ENTRY_EXIT(r5)
+        cmpwi   r0, 0x100
+        bge     ext_interrupt_to_host
+
+        /* See if there is a pending interrupt for the guest */
+        mfspr   r8, SPRN_LPCR
+        ld      r0, VCPU_PENDING_EXC(r9)
+        /* Insert EXTERNAL_LEVEL bit into LPCR at the MER bit position */
+        rldicl. r0, r0, 64 - BOOK3S_IRQPRIO_EXTERNAL_LEVEL, 63
+        rldimi  r8, r0, LPCR_MER_SH, 63 - LPCR_MER_SH
+        beq     2f
 
         /* And if the guest EE is set, we can deliver immediately, else
          * we return to the guest with MER set
          */
         andi.   r0, r11, MSR_EE
-        bne     bounce_ext_interrupt
-        mr      r4, r9
+        beq     2f
+        mtspr   SPRN_SRR0, r10
+        mtspr   SPRN_SRR1, r11
+        li      r10, BOOK3S_INTERRUPT_EXTERNAL
+        li      r11, (MSR_ME << 1) | 1  /* synthesize MSR_SF | MSR_ME */
+        rotldi  r11, r11, 63
+2:      mr      r4, r9
+        mtspr   SPRN_LPCR, r8
         b       fast_guest_return
 
         /* We raced with the host, we need to resend that IPI, bummer */
@@ -1487,15 +1496,6 @@ ignore_hdec:
         mr      r4,r9
         b       fast_guest_return
 
-bounce_ext_interrupt:
-        mr      r4,r9
-        mtspr   SPRN_SRR0,r10
-        mtspr   SPRN_SRR1,r11
-        li      r10,BOOK3S_INTERRUPT_EXTERNAL
-        li      r11,(MSR_ME << 1) | 1   /* synthesize MSR_SF | MSR_ME */
-        rotldi  r11,r11,63
-        b       fast_guest_return
-
 _GLOBAL(kvmppc_h_set_dabr)
         std     r4,VCPU_DABR(r3)
         /* Work around P7 bug where DABR can get corrupted on mtspr */
@@ -1601,6 +1601,9 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_206)
         b       .
 
 kvm_end_cede:
+        /* get vcpu pointer */
+        ld      r4, HSTATE_KVM_VCPU(r13)
+
         /* Woken by external or decrementer interrupt */
         ld      r1, HSTATE_HOST_R1(r13)
 
@@ -1640,6 +1643,16 @@ kvm_end_cede:
         li      r0,0
         stb     r0,HSTATE_NAPPING(r13)
 
+        /* Check the wake reason in SRR1 to see why we got here */
+        mfspr   r3, SPRN_SRR1
+        rlwinm  r3, r3, 44-31, 0x7      /* extract wake reason field */
+        cmpwi   r3, 4                   /* was it an external interrupt? */
+        li      r12, BOOK3S_INTERRUPT_EXTERNAL
+        mr      r9, r4
+        ld      r10, VCPU_PC(r9)
+        ld      r11, VCPU_MSR(r9)
+        beq     do_ext_interrupt        /* if so */
+
         /* see if any other thread is already exiting */
         lwz     r0,VCORE_ENTRY_EXIT(r5)
         cmpwi   r0,0x100
@@ -1659,8 +1672,7 @@ kvm_cede_prodded:
 
         /* we've ceded but we want to give control to the host */
 kvm_cede_exit:
-        li      r3,H_TOO_HARD
-        blr
+        b       hcall_real_fallback
 
         /* Try to handle a machine check in real mode */
 machine_check_realmode: