KVM: PPC: Book3S HV: Handle guest using doorbells for IPIs

* SRR1 wake reason field for system reset interrupt on wakeup from nap
  is now a 4-bit field on P8, compared to 3 bits on P7.

* Set PECEDP in LPCR when napping because of H_CEDE so guest doorbells
  will wake us up.

* Waking up from nap because of a guest doorbell interrupt is not a
  reason to exit the guest.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>

2 files changed, 18 insertions, 5 deletions

diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index 5a9983147683..1248b40107ea 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -307,7 +307,9 @@
 #define   LPCR_ILE     0x02000000      /* !HV irqs set MSR:LE */
 #define   LPCR_AIL_0    0x00000000      /* MMU off exception offset 0x0 */
 #define   LPCR_AIL_3    0x01800000      /* MMU on exception offset 0xc00...4xxx */
-#define   LPCR_PECE     0x00007000      /* powersave exit cause enable */
+#define   LPCR_PECE     0x0001f000      /* powersave exit cause enable */
+#define     LPCR_PECEDP 0x00010000      /* directed priv dbells cause exit */
+#define     LPCR_PECEDH 0x00008000      /* directed hyp dbells cause exit */
 #define     LPCR_PECE0  0x00004000      /* ext. exceptions can cause exit */
 #define     LPCR_PECE1  0x00002000      /* decrementer can cause exit */
 #define     LPCR_PECE2  0x00001000      /* machine check etc can cause exit */
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 386e141dbf16..9e89c7577b4a 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -1857,13 +1857,16 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_206)
         bl      kvmppc_save_fp
 
         /*
-         * Take a nap until a decrementer or external interrupt occurs,
-         * with PECE1 (wake on decr) and PECE0 (wake on external) set in LPCR
+         * Take a nap until a decrementer or external or doobell interrupt
+         * occurs, with PECE1, PECE0 and PECEDP set in LPCR
          */
         li      r0,1
         stb     r0,HSTATE_HWTHREAD_REQ(r13)
         mfspr   r5,SPRN_LPCR
         ori     r5,r5,LPCR_PECE0 | LPCR_PECE1
+BEGIN_FTR_SECTION
+        oris    r5,r5,LPCR_PECEDP@h
+END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
         mtspr   SPRN_LPCR,r5
         isync
         li      r0, 0
@@ -1979,14 +1982,22 @@ machine_check_realmode:
  */
 kvmppc_check_wake_reason:
         mfspr   r6, SPRN_SRR1
-        rlwinm  r6, r6, 44-31, 0x7      /* extract wake reason field */
-        cmpwi   r6, 4                   /* was it an external interrupt? */
+BEGIN_FTR_SECTION
+        rlwinm  r6, r6, 45-31, 0xf      /* extract wake reason field (P8) */
+FTR_SECTION_ELSE
+        rlwinm  r6, r6, 45-31, 0xe      /* P7 wake reason field is 3 bits */
+ALT_FTR_SECTION_END_IFSET(CPU_FTR_ARCH_207S)
+        cmpwi   r6, 8                   /* was it an external interrupt? */
         li      r12, BOOK3S_INTERRUPT_EXTERNAL
         beq     kvmppc_read_intr        /* if so, see what it was */
         li      r3, 0
         li      r12, 0
         cmpwi   r6, 6                   /* was it the decrementer? */
         beq     0f
+BEGIN_FTR_SECTION
+        cmpwi   r6, 5                   /* privileged doorbell? */
+        beq     0f
+END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
         li      r3, 1                   /* anything else, return 1 */
 0:      blr