KVM: PPC: e500: Save/restore SPE state

This is done lazily.  The SPE save will be done only if the guest has
used SPE since the last preemption or heavyweight exit.  Restore will be
done only on demand, when enabling MSR_SPE in the shadow MSR, in response
to an SPE fault or mtmsr emulation.

For SPEFSCR, Linux already switches it on context switch (non-lazily), so
the only remaining bit is to save it between qemu and the guest.

Signed-off-by: Liu Yu <yu.liu@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>

diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 12cb1807e8d7f96d1a1bcfc18d93160705b46c33..c4ce1054b866b62c7d4748bc8ad9b44d26b80864 100644 (file)
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -195,6 +195,12 @@ struct kvm_vcpu_arch {
        u64 fpr[32];
        u64 fpscr;
 
+#ifdef CONFIG_SPE
+       ulong evr[32];
+       ulong spefscr;
+       ulong host_spefscr;
+       u64 acc;
+#endif
 #ifdef CONFIG_ALTIVEC
        vector128 vr[32];
        vector128 vscr;

diff --git a/arch/powerpc/include/asm/reg_booke.h b/arch/powerpc/include/asm/reg_booke.h
index 0f0ad9fa01c1f91b992c45d9342fc7261fef2747..9ec0b39f9ddc3cf98a65c67b452e021519783d1e 100644 (file)
--- a/arch/powerpc/include/asm/reg_booke.h
+++ b/arch/powerpc/include/asm/reg_booke.h
@@ -318,6 +318,7 @@
 #define ESR_ILK                0x00100000      /* Instr. Cache Locking */
 #define ESR_PUO                0x00040000      /* Unimplemented Operation exception */
 #define ESR_BO         0x00020000      /* Byte Ordering */
+#define ESR_SPV                0x00000080      /* Signal Processing operation */
 
 /* Bit definitions related to the DBCR0. */
 #if defined(CONFIG_40x)

diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 25de8e4808a45fd6f75c366731b66fc8d73b20bc..ecd2b3ad7ff633bff7bd346fec275a744b36f44f 100644 (file)
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -497,6 +497,13 @@ int main(void)
        DEFINE(TLBCAM_MAS7, offsetof(struct tlbcam, MAS7));
 #endif
 
+#if defined(CONFIG_KVM) && defined(CONFIG_SPE)
+       DEFINE(VCPU_EVR, offsetof(struct kvm_vcpu, arch.evr[0]));
+       DEFINE(VCPU_ACC, offsetof(struct kvm_vcpu, arch.acc));
+       DEFINE(VCPU_SPEFSCR, offsetof(struct kvm_vcpu, arch.spefscr));
+       DEFINE(VCPU_HOST_SPEFSCR, offsetof(struct kvm_vcpu, arch.host_spefscr));
+#endif
+
 #ifdef CONFIG_KVM_EXIT_TIMING
        DEFINE(VCPU_TIMING_EXIT_TBU, offsetof(struct kvm_vcpu,
                                                arch.timing_exit.tv32.tbu));

diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index 05cedb5f82100a01351c465d757cb5309ab0edeb..0ecbecb2f7cc83baba524ae782efd833c664cf84 100644 (file)
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -13,6 +13,7 @@
  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  *
  * Copyright IBM Corp. 2007
+ * Copyright 2010-2011 Freescale Semiconductor, Inc.
  *
  * Authors: Hollis Blanchard <hollisb@us.ibm.com>
  *          Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
@@ -78,6 +79,57 @@ void kvmppc_dump_vcpu(struct kvm_vcpu *vcpu)
        }
 }
 
+#ifdef CONFIG_SPE
+void kvmppc_vcpu_disable_spe(struct kvm_vcpu *vcpu)
+{
+       preempt_disable();
+       enable_kernel_spe();
+       kvmppc_save_guest_spe(vcpu);
+       vcpu->arch.shadow_msr &= ~MSR_SPE;
+       preempt_enable();
+}
+
+static void kvmppc_vcpu_enable_spe(struct kvm_vcpu *vcpu)
+{
+       preempt_disable();
+       enable_kernel_spe();
+       kvmppc_load_guest_spe(vcpu);
+       vcpu->arch.shadow_msr |= MSR_SPE;
+       preempt_enable();
+}
+
+static void kvmppc_vcpu_sync_spe(struct kvm_vcpu *vcpu)
+{
+       if (vcpu->arch.shared->msr & MSR_SPE) {
+               if (!(vcpu->arch.shadow_msr & MSR_SPE))
+                       kvmppc_vcpu_enable_spe(vcpu);
+       } else if (vcpu->arch.shadow_msr & MSR_SPE) {
+               kvmppc_vcpu_disable_spe(vcpu);
+       }
+}
+#else
+static void kvmppc_vcpu_sync_spe(struct kvm_vcpu *vcpu)
+{
+}
+#endif
+
+/* Helper function for "full" MSR writes. No need to call this if only EE is
+ * changing. */
+void kvmppc_set_msr(struct kvm_vcpu *vcpu, u32 new_msr)
+{
+       if ((new_msr & MSR_PR) != (vcpu->arch.shared->msr & MSR_PR))
+               kvmppc_mmu_priv_switch(vcpu, new_msr & MSR_PR);
+
+       vcpu->arch.shared->msr = new_msr;
+
+       if (vcpu->arch.shared->msr & MSR_WE) {
+               kvm_vcpu_block(vcpu);
+               kvmppc_set_exit_type(vcpu, EMULATED_MTMSRWE_EXITS);
+       };
+
+       kvmppc_vcpu_sync_spe(vcpu);
+}
+
 static void kvmppc_booke_queue_irqprio(struct kvm_vcpu *vcpu,
                                        unsigned int priority)
 {
@@ -344,10 +396,16 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
                r = RESUME_GUEST;
                break;
 
-       case BOOKE_INTERRUPT_SPE_UNAVAIL:
-               kvmppc_booke_queue_irqprio(vcpu, BOOKE_IRQPRIO_SPE_UNAVAIL);
+#ifdef CONFIG_SPE
+       case BOOKE_INTERRUPT_SPE_UNAVAIL: {
+               if (vcpu->arch.shared->msr & MSR_SPE)
+                       kvmppc_vcpu_enable_spe(vcpu);
+               else
+                       kvmppc_booke_queue_irqprio(vcpu,
+                                                  BOOKE_IRQPRIO_SPE_UNAVAIL);
                r = RESUME_GUEST;
                break;
+       }
 
        case BOOKE_INTERRUPT_SPE_FP_DATA:
                kvmppc_booke_queue_irqprio(vcpu, BOOKE_IRQPRIO_SPE_FP_DATA);
@@ -358,6 +416,28 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
                kvmppc_booke_queue_irqprio(vcpu, BOOKE_IRQPRIO_SPE_FP_ROUND);
                r = RESUME_GUEST;
                break;
+#else
+       case BOOKE_INTERRUPT_SPE_UNAVAIL:
+               /*
+                * Guest wants SPE, but host kernel doesn't support it.  Send
+                * an "unimplemented operation" program check to the guest.
+                */
+               kvmppc_core_queue_program(vcpu, ESR_PUO | ESR_SPV);
+               r = RESUME_GUEST;
+               break;
+
+       /*
+        * These really should never happen without CONFIG_SPE,
+        * as we should never enable the real MSR[SPE] in the guest.
+        */
+       case BOOKE_INTERRUPT_SPE_FP_DATA:
+       case BOOKE_INTERRUPT_SPE_FP_ROUND:
+               printk(KERN_CRIT "%s: unexpected SPE interrupt %u at %08lx\n",
+                      __func__, exit_nr, vcpu->arch.pc);
+               run->hw.hardware_exit_reason = exit_nr;
+               r = RESUME_HOST;
+               break;
+#endif
 
        case BOOKE_INTERRUPT_DATA_STORAGE:
                kvmppc_core_queue_data_storage(vcpu, vcpu->arch.fault_dear,

diff --git a/arch/powerpc/kvm/booke.h b/arch/powerpc/kvm/booke.h
index 492bb7030358275c9fd6e4977e7d8e819cfd6f9e..0fa1732ddcb7894be9121e71a67db57681fe21a1 100644 (file)
--- a/arch/powerpc/kvm/booke.h
+++ b/arch/powerpc/kvm/booke.h
@@ -52,24 +52,18 @@
 
 extern unsigned long kvmppc_booke_handlers;
 
-/* Helper function for "full" MSR writes. No need to call this if only EE is
- * changing. */
-static inline void kvmppc_set_msr(struct kvm_vcpu *vcpu, u32 new_msr)
-{
-       if ((new_msr & MSR_PR) != (vcpu->arch.shared->msr & MSR_PR))
-               kvmppc_mmu_priv_switch(vcpu, new_msr & MSR_PR);
-
-       vcpu->arch.shared->msr = new_msr;
-
-       if (vcpu->arch.shared->msr & MSR_WE) {
-               kvm_vcpu_block(vcpu);
-               kvmppc_set_exit_type(vcpu, EMULATED_MTMSRWE_EXITS);
-       };
-}
+void kvmppc_set_msr(struct kvm_vcpu *vcpu, u32 new_msr);
 
 int kvmppc_booke_emulate_op(struct kvm_run *run, struct kvm_vcpu *vcpu,
                             unsigned int inst, int *advance);
 int kvmppc_booke_emulate_mfspr(struct kvm_vcpu *vcpu, int sprn, int rt);
 int kvmppc_booke_emulate_mtspr(struct kvm_vcpu *vcpu, int sprn, int rs);
 
+/* low-level asm code to transfer guest state */
+void kvmppc_load_guest_spe(struct kvm_vcpu *vcpu);
+void kvmppc_save_guest_spe(struct kvm_vcpu *vcpu);
+
+/* high-level function, manages flags, host state */
+void kvmppc_vcpu_disable_spe(struct kvm_vcpu *vcpu);
+
 #endif /* __KVM_BOOKE_H__ */

diff --git a/arch/powerpc/kvm/booke_interrupts.S b/arch/powerpc/kvm/booke_interrupts.S
index 55410cc45ad734b898d588bd6e2fb35a233dfa4e..8cb3dfe29f7549fbe3c0da5e8a24dcec7551b67d 100644 (file)
--- a/arch/powerpc/kvm/booke_interrupts.S
+++ b/arch/powerpc/kvm/booke_interrupts.S
@@ -13,6 +13,7 @@
  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  *
  * Copyright IBM Corp. 2007
+ * Copyright 2011 Freescale Semiconductor, Inc.
  *
  * Authors: Hollis Blanchard <hollisb@us.ibm.com>
  */
@@ -239,6 +240,14 @@ _GLOBAL(kvmppc_resume_host)
 heavyweight_exit:
        /* Not returning to guest. */
 
+#ifdef CONFIG_SPE
+       /* save guest SPEFSCR and load host SPEFSCR */
+       mfspr   r9, SPRN_SPEFSCR
+       stw     r9, VCPU_SPEFSCR(r4)
+       lwz     r9, VCPU_HOST_SPEFSCR(r4)
+       mtspr   SPRN_SPEFSCR, r9
+#endif
+
        /* We already saved guest volatile register state; now save the
         * non-volatiles. */
        stw     r15, VCPU_GPR(r15)(r4)
@@ -340,6 +349,14 @@ _GLOBAL(__kvmppc_vcpu_run)
        lwz     r30, VCPU_GPR(r30)(r4)
        lwz     r31, VCPU_GPR(r31)(r4)
 
+#ifdef CONFIG_SPE
+       /* save host SPEFSCR and load guest SPEFSCR */
+       mfspr   r3, SPRN_SPEFSCR
+       stw     r3, VCPU_HOST_SPEFSCR(r4)
+       lwz     r3, VCPU_SPEFSCR(r4)
+       mtspr   SPRN_SPEFSCR, r3
+#endif
+
 lightweight_exit:
        stw     r2, HOST_R2(r1)
 
@@ -425,3 +442,24 @@ lightweight_exit:
        lwz     r3, VCPU_GPR(r3)(r4)
        lwz     r4, VCPU_GPR(r4)(r4)
        rfi
+
+#ifdef CONFIG_SPE
+_GLOBAL(kvmppc_save_guest_spe)
+       cmpi    0,r3,0
+       beqlr-
+       SAVE_32EVRS(0, r4, r3, VCPU_EVR)
+       evxor   evr6, evr6, evr6
+       evmwumiaa evr6, evr6, evr6
+       li      r4,VCPU_ACC
+       evstddx evr6, r4, r3            /* save acc */
+       blr
+
+_GLOBAL(kvmppc_load_guest_spe)
+       cmpi    0,r3,0
+       beqlr-
+       li      r4,VCPU_ACC
+       evlddx  evr6,r4,r3
+       evmra   evr6,evr6               /* load acc */
+       REST_32EVRS(0, r4, r3, VCPU_EVR)
+       blr
+#endif

diff --git a/arch/powerpc/kvm/e500.c b/arch/powerpc/kvm/e500.c
index 318dbc61ba447e7352107de95daa59053e191d16..797a7447c268aff9f0ee603ab8c22c0546ba4d4c 100644 (file)
--- a/arch/powerpc/kvm/e500.c
+++ b/arch/powerpc/kvm/e500.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2008 Freescale Semiconductor, Inc. All rights reserved.
+ * Copyright (C) 2008-2011 Freescale Semiconductor, Inc. All rights reserved.
  *
  * Author: Yu Liu, <yu.liu@freescale.com>
  *
@@ -41,6 +41,11 @@ void kvmppc_core_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 void kvmppc_core_vcpu_put(struct kvm_vcpu *vcpu)
 {
        kvmppc_e500_tlb_put(vcpu);
+
+#ifdef CONFIG_SPE
+       if (vcpu->arch.shadow_msr & MSR_SPE)
+               kvmppc_vcpu_disable_spe(vcpu);
+#endif
 }
 
 int kvmppc_core_check_processor_compat(void)