KVM: PPC: Book3S HV: Prepare for host using hypervisor doorbells

POWER8 has support for hypervisor doorbell interrupts.  Though the
kernel doesn't use them for IPIs on the powernv platform yet, it
probably will in future, so this makes KVM cope gracefully if a
hypervisor doorbell interrupt arrives while in a guest.

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

3 files changed, 9 insertions, 0 deletions

diff --git a/arch/powerpc/include/asm/kvm_asm.h b/arch/powerpc/include/asm/kvm_asm.h
index dba8fb244100..c3815b1e79e8 100644
--- a/arch/powerpc/include/asm/kvm_asm.h
+++ b/arch/powerpc/include/asm/kvm_asm.h
@@ -96,6 +96,7 @@
 #define BOOK3S_INTERRUPT_H_DATA_STORAGE 0xe00
 #define BOOK3S_INTERRUPT_H_INST_STORAGE 0xe20
 #define BOOK3S_INTERRUPT_H_EMUL_ASSIST  0xe40
+#define BOOK3S_INTERRUPT_H_DOORBELL     0xe80
 #define BOOK3S_INTERRUPT_PERFMON        0xf00
 #define BOOK3S_INTERRUPT_ALTIVEC        0xf20
 #define BOOK3S_INTERRUPT_VSX            0xf40
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index d7f2ec6f1419..216049ff7368 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -651,6 +651,7 @@ static int kvmppc_handle_exit_hv(struct kvm_run *run, struct kvm_vcpu *vcpu,
                 r = RESUME_GUEST;
                 break;
         case BOOK3S_INTERRUPT_EXTERNAL:
+        case BOOK3S_INTERRUPT_H_DOORBELL:
                 vcpu->stat.ext_intr_exits++;
                 r = RESUME_GUEST;
                 break;
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 9e89c7577b4a..eae4ab9b9135 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -1997,10 +1997,17 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_ARCH_207S)
 BEGIN_FTR_SECTION
         cmpwi   r6, 5                   /* privileged doorbell? */
         beq     0f
+        cmpwi   r6, 3                   /* hypervisor doorbell? */
+        beq     3f
 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
         li      r3, 1                   /* anything else, return 1 */
 0:      blr
 
+        /* hypervisor doorbell */
+3:      li      r12, BOOK3S_INTERRUPT_H_DOORBELL
+        li      r3, 1
+        blr
+
 /*
  * Determine what sort of external interrupt is pending (if any).
  * Returns: