6 files changed, 59 insertions, 9 deletions

diff --git a/Documentation/kvm/api.txt b/Documentation/kvm/api.txt
index f9724dc8d079..6f362356e738 100644
--- a/Documentation/kvm/api.txt
+++ b/Documentation/kvm/api.txt
@@ -958,9 +958,9 @@ executed a memory-mapped I/O instruction which could not be satisfied
 by kvm.  The 'data' member contains the written data if 'is_write' is
 true, and should be filled by application code otherwise.
 
-NOTE: For KVM_EXIT_IO and KVM_EXIT_MMIO, the corresponding operations
-are complete (and guest state is consistent) only after userspace has
-re-entered the kernel with KVM_RUN.  The kernel side will first finish
+NOTE: For KVM_EXIT_IO, KVM_EXIT_MMIO and KVM_EXIT_OSI, the corresponding
+operations are complete (and guest state is consistent) only after userspace
+has re-entered the kernel with KVM_RUN.  The kernel side will first finish
 incomplete operations and then check for pending signals.  Userspace
 can re-enter the guest with an unmasked signal pending to complete
 pending operations.
@@ -1015,6 +1015,19 @@ s390 specific.
 
 powerpc specific.
 
+                /* KVM_EXIT_OSI */
+                struct {
+                        __u64 gprs[32];
+                } osi;
+
+MOL uses a special hypercall interface it calls 'OSI'. To enable it, we catch
+hypercalls and exit with this exit struct that contains all the guest gprs.
+
+If exit_reason is KVM_EXIT_OSI, then the vcpu has triggered such a hypercall.
+Userspace can now handle the hypercall and when it's done modify the gprs as
+necessary. Upon guest entry all guest GPRs will then be replaced by the values
+in this struct.
+
                 /* Fix the size of the union. */
                 char padding[256];
         };
diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h
index bea76371dbe1..7e243b2cac72 100644
--- a/arch/powerpc/include/asm/kvm_book3s.h
+++ b/arch/powerpc/include/asm/kvm_book3s.h
@@ -148,6 +148,11 @@ static inline ulong dsisr(void)
 
 extern void kvm_return_point(void);
 
+/* Magic register values loaded into r3 and r4 before the 'sc' assembly
+ * instruction for the OSI hypercalls */
+#define OSI_SC_MAGIC_R3                 0x113724FA
+#define OSI_SC_MAGIC_R4                 0x77810F9B
+
 #define INS_DCBZ                        0x7c0007ec
 
 #endif /* __ASM_KVM_BOOK3S_H__ */
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 0ebda67ad6a8..486f1cafd5f7 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -273,6 +273,8 @@ struct kvm_vcpu_arch {
         u8 mmio_sign_extend;
         u8 dcr_needed;
         u8 dcr_is_write;
+        u8 osi_needed;
+        u8 osi_enabled;
 
         u32 cpr0_cfgaddr; /* holds the last set cpr0_cfgaddr */
 
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index de12202fe1c6..7696d0f547e3 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -872,12 +872,24 @@ program_interrupt:
                 break;
         }
         case BOOK3S_INTERRUPT_SYSCALL:
-#ifdef EXIT_DEBUG
-                printk(KERN_INFO "Syscall Nr %d\n", (int)kvmppc_get_gpr(vcpu, 0));
-#endif
-                vcpu->stat.syscall_exits++;
-                kvmppc_book3s_queue_irqprio(vcpu, exit_nr);
-                r = RESUME_GUEST;
+                // XXX make user settable
+                if (vcpu->arch.osi_enabled &&
+                    (((u32)kvmppc_get_gpr(vcpu, 3)) == OSI_SC_MAGIC_R3) &&
+                    (((u32)kvmppc_get_gpr(vcpu, 4)) == OSI_SC_MAGIC_R4)) {
+                        u64 *gprs = run->osi.gprs;
+                        int i;
+
+                        run->exit_reason = KVM_EXIT_OSI;
+                        for (i = 0; i < 32; i++)
+                                gprs[i] = kvmppc_get_gpr(vcpu, i);
+                        vcpu->arch.osi_needed = 1;
+                        r = RESUME_HOST_NV;
+
+                } else {
+                        vcpu->stat.syscall_exits++;
+                        kvmppc_book3s_queue_irqprio(vcpu, exit_nr);
+                        r = RESUME_GUEST;
+                }
                 break;
         case BOOK3S_INTERRUPT_FP_UNAVAIL:
         case BOOK3S_INTERRUPT_ALTIVEC:
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 646bfd256e5d..9a4dd8146d39 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -151,6 +151,7 @@ int kvm_dev_ioctl_check_extension(long ext)
         case KVM_CAP_PPC_PAIRED_SINGLES:
         case KVM_CAP_PPC_UNSET_IRQ:
         case KVM_CAP_ENABLE_CAP:
+        case KVM_CAP_PPC_OSI:
                 r = 1;
                 break;
         case KVM_CAP_COALESCED_MMIO:
@@ -433,6 +434,13 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
                 if (!vcpu->arch.dcr_is_write)
                         kvmppc_complete_dcr_load(vcpu, run);
                 vcpu->arch.dcr_needed = 0;
+        } else if (vcpu->arch.osi_needed) {
+                u64 *gprs = run->osi.gprs;
+                int i;
+
+                for (i = 0; i < 32; i++)
+                        kvmppc_set_gpr(vcpu, i, gprs[i]);
+                vcpu->arch.osi_needed = 0;
         }
 
         kvmppc_core_deliver_interrupts(vcpu);
@@ -475,6 +483,10 @@ static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,
                 return -EINVAL;
 
         switch (cap->cap) {
+        case KVM_CAP_PPC_OSI:
+                r = 0;
+                vcpu->arch.osi_enabled = true;
+                break;
         default:
                 r = -EINVAL;
                 break;
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index ecb68e433558..23ea02253900 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -160,6 +160,7 @@ struct kvm_pit_config {
 #define KVM_EXIT_DCR              15
 #define KVM_EXIT_NMI              16
 #define KVM_EXIT_INTERNAL_ERROR   17
+#define KVM_EXIT_OSI              18
 
 /* For KVM_EXIT_INTERNAL_ERROR */
 #define KVM_INTERNAL_ERROR_EMULATION 1
@@ -259,6 +260,10 @@ struct kvm_run {
                         __u32 ndata;
                         __u64 data[16];
                 } internal;
+                /* KVM_EXIT_OSI */
+                struct {
+                        __u64 gprs[32];
+                } osi;
                 /* Fix the size of the union. */
                 char padding[256];
         };
@@ -516,6 +521,7 @@ struct kvm_enable_cap {
 #define KVM_CAP_DEBUGREGS 50
 #endif
 #define KVM_CAP_X86_ROBUST_SINGLESTEP 51
+#define KVM_CAP_PPC_OSI 52
 #define KVM_CAP_PPC_UNSET_IRQ 53
 #define KVM_CAP_ENABLE_CAP 54