[PULL 18/41] KVM: PPC: Book3S PR: Handle Facility interrupt and FSCR

Alexander Graf
2014-05-30T12:43:04Z

POWER8 introduced a new interrupt type called "Facility unavailable interrupt"
which contains its status message in a new register called FSCR.

Handle these exits and try to emulate instructions for unhandled facilities.
Follow-on patches enable KVM to expose specific facilities into the guest.

Signed-off-by: Alexander Graf <agraf@suse.de>
---
arch/powerpc/include/asm/kvm_asm.h | 18 ++++----
arch/powerpc/include/asm/kvm_book3s_asm.h | 2 +
arch/powerpc/include/asm/kvm_host.h | 1 +
arch/powerpc/kernel/asm-offsets.c | 3 ++
arch/powerpc/kvm/book3s.c | 10 +++++
arch/powerpc/kvm/book3s_emulate.c | 6 +++
arch/powerpc/kvm/book3s_hv.c | 6 ---
arch/powerpc/kvm/book3s_pr.c | 68 +++++++++++++++++++++++++++++++
arch/powerpc/kvm/book3s_segment.S | 25 ++++++++++++
9 files changed, 125 insertions(+), 14 deletions(-)

diff --git a/arch/powerpc/include/asm/kvm_asm.h b/arch/powerpc/include/asm/kvm_asm.h
index 19eb74a..9601741 100644
--- a/arch/powerpc/include/asm/kvm_asm.h
+++ b/arch/powerpc/include/asm/kvm_asm.h
@@ -102,6 +102,7 @@
#define BOOK3S_INTERRUPT_PERFMON 0xf00
#define BOOK3S_INTERRUPT_ALTIVEC 0xf20
#define BOOK3S_INTERRUPT_VSX 0xf40
+#define BOOK3S_INTERRUPT_FAC_UNAVAIL 0xf60
#define BOOK3S_INTERRUPT_H_FAC_UNAVAIL 0xf80

#define BOOK3S_IRQPRIO_SYSTEM_RESET 0
@@ -114,14 +115,15 @@
#define BOOK3S_IRQPRIO_FP_UNAVAIL 7
#define BOOK3S_IRQPRIO_ALTIVEC 8
#define BOOK3S_IRQPRIO_VSX 9
-#define BOOK3S_IRQPRIO_SYSCALL 10
-#define BOOK3S_IRQPRIO_MACHINE_CHECK 11
-#define BOOK3S_IRQPRIO_DEBUG 12
-#define BOOK3S_IRQPRIO_EXTERNAL 13
-#define BOOK3S_IRQPRIO_DECREMENTER 14
-#define BOOK3S_IRQPRIO_PERFORMANCE_MONITOR 15
-#define BOOK3S_IRQPRIO_EXTERNAL_LEVEL 16
-#define BOOK3S_IRQPRIO_MAX 17
+#define BOOK3S_IRQPRIO_FAC_UNAVAIL 10
+#define BOOK3S_IRQPRIO_SYSCALL 11
+#define BOOK3S_IRQPRIO_MACHINE_CHECK 12
+#define BOOK3S_IRQPRIO_DEBUG 13
+#define BOOK3S_IRQPRIO_EXTERNAL 14
+#define BOOK3S_IRQPRIO_DECREMENTER 15
+#define BOOK3S_IRQPRIO_PERFORMANCE_MONITOR 16
+#define BOOK3S_IRQPRIO_EXTERNAL_LEVEL 17
+#define BOOK3S_IRQPRIO_MAX 18

#define BOOK3S_HFLAG_DCBZ32 0x1
#define BOOK3S_HFLAG_SLB 0x2
diff --git a/arch/powerpc/include/asm/kvm_book3s_asm.h b/arch/powerpc/include/asm/kvm_book3s_asm.h
index 821725c..5bdfb5d 100644
--- a/arch/powerpc/include/asm/kvm_book3s_asm.h
+++ b/arch/powerpc/include/asm/kvm_book3s_asm.h
@@ -104,6 +104,7 @@ struct kvmppc_host_state {
#ifdef CONFIG_PPC_BOOK3S_64
u64 cfar;
u64 ppr;
+ u64 host_fscr;
#endif
};

@@ -133,6 +134,7 @@ struct kvmppc_book3s_shadow_vcpu {
u64 esid;
u64 vsid;
} slb[64]; /* guest SLB */
+ u64 shadow_fscr;
#endif
};

diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 15f19d3..232ec5f 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -475,6 +475,7 @@ struct kvm_vcpu_arch {
ulong ppr;
ulong pspb;
ulong fscr;
+ ulong shadow_fscr;
ulong ebbhr;
ulong ebbrr;
ulong bescr;
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index bbf3b9a..e2b86b5 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -537,6 +537,7 @@ int main(void)
DEFINE(VCPU_CFAR, offsetof(struct kvm_vcpu, arch.cfar));
DEFINE(VCPU_PPR, offsetof(struct kvm_vcpu, arch.ppr));
DEFINE(VCPU_FSCR, offsetof(struct kvm_vcpu, arch.fscr));
+ DEFINE(VCPU_SHADOW_FSCR, offsetof(struct kvm_vcpu, arch.shadow_fscr));
DEFINE(VCPU_PSPB, offsetof(struct kvm_vcpu, arch.pspb));
DEFINE(VCPU_EBBHR, offsetof(struct kvm_vcpu, arch.ebbhr));
DEFINE(VCPU_EBBRR, offsetof(struct kvm_vcpu, arch.ebbrr));
@@ -618,6 +619,7 @@ int main(void)
#ifdef CONFIG_PPC64
SVCPU_FIELD(SVCPU_SLB, slb);
SVCPU_FIELD(SVCPU_SLB_MAX, slb_max);
+ SVCPU_FIELD(SVCPU_SHADOW_FSCR, shadow_fscr);
#endif

HSTATE_FIELD(HSTATE_HOST_R1, host_r1);
@@ -653,6 +655,7 @@ int main(void)
#ifdef CONFIG_PPC_BOOK3S_64
HSTATE_FIELD(HSTATE_CFAR, cfar);
HSTATE_FIELD(HSTATE_PPR, ppr);
+ HSTATE_FIELD(HSTATE_HOST_FSCR, host_fscr);
#endif /* CONFIG_PPC_BOOK3S_64 */

#else /* CONFIG_PPC_BOOK3S */
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index 81abc5c..79cfa2d 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -145,6 +145,7 @@ static int kvmppc_book3s_vec2irqprio(unsigned int vec)
case 0xd00: prio = BOOK3S_IRQPRIO_DEBUG; break;
case 0xf20: prio = BOOK3S_IRQPRIO_ALTIVEC; break;
case 0xf40: prio = BOOK3S_IRQPRIO_VSX; break;
+ case 0xf60: prio = BOOK3S_IRQPRIO_FAC_UNAVAIL; break;
default: prio = BOOK3S_IRQPRIO_MAX; break;
}

@@ -275,6 +276,9 @@ int kvmppc_book3s_irqprio_deliver(struct kvm_vcpu *vcpu, unsigned int priority)
case BOOK3S_IRQPRIO_PERFORMANCE_MONITOR:
vec = BOOK3S_INTERRUPT_PERFMON;
break;
+ case BOOK3S_IRQPRIO_FAC_UNAVAIL:
+ vec = BOOK3S_INTERRUPT_FAC_UNAVAIL;
+ break;
default:
deliver = 0;
printk(KERN_ERR "KVM: Unknown interrupt: 0x%x\n", priority);
@@ -627,6 +631,9 @@ int kvm_vcpu_ioctl_get_one_reg(struct kvm_vcpu *vcpu, struct kvm_one_reg *reg)
val = get_reg_val(reg->id, kvmppc_xics_get_icp(vcpu));
break;
#endif /* CONFIG_KVM_XICS */
+ case KVM_REG_PPC_FSCR:
+ val = get_reg_val(reg->id, vcpu->arch.fscr);
+ break;
default:
r = -EINVAL;
break;
@@ -716,6 +723,9 @@ int kvm_vcpu_ioctl_set_one_reg(struct kvm_vcpu *vcpu, struct kvm_one_reg *reg)
set_reg_val(reg->id, val));
break;
#endif /* CONFIG_KVM_XICS */
+ case KVM_REG_PPC_FSCR:
+ vcpu->arch.fscr = set_reg_val(reg->id, val);
+ break;
default:
r = -EINVAL;
break;
diff --git a/arch/powerpc/kvm/book3s_emulate.c b/arch/powerpc/kvm/book3s_emulate.c
index 0a1de29..e8133e5 100644
--- a/arch/powerpc/kvm/book3s_emulate.c
+++ b/arch/powerpc/kvm/book3s_emulate.c
@@ -438,6 +438,9 @@ int kvmppc_core_emulate_mtspr_pr(struct kvm_vcpu *vcpu, int sprn, ulong spr_val)
case SPRN_GQR7:
to_book3s(vcpu)->gqr[sprn - SPRN_GQR0] = spr_val;
break;
+ case SPRN_FSCR:
+ vcpu->arch.fscr = spr_val;
+ break;
case SPRN_ICTC:
case SPRN_THRM1:
case SPRN_THRM2:
@@ -545,6 +548,9 @@ int kvmppc_core_emulate_mfspr_pr(struct kvm_vcpu *vcpu, int sprn, ulong *spr_val
case SPRN_GQR7:
*spr_val = to_book3s(vcpu)->gqr[sprn - SPRN_GQR0];
break;
+ case SPRN_FSCR:
+ *spr_val = vcpu->arch.fscr;
+ break;
case SPRN_THRM1:
case SPRN_THRM2:
case SPRN_THRM3:
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 030821a..0092e12 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -879,9 +879,6 @@ static int kvmppc_get_one_reg_hv(struct kvm_vcpu *vcpu, u64 id,
case KVM_REG_PPC_IAMR:
*val = get_reg_val(id, vcpu->arch.iamr);
break;
- case KVM_REG_PPC_FSCR:
- *val = get_reg_val(id, vcpu->arch.fscr);
- break;
case KVM_REG_PPC_PSPB:
*val = get_reg_val(id, vcpu->arch.pspb);
break;
@@ -1091,9 +1088,6 @@ static int kvmppc_set_one_reg_hv(struct kvm_vcpu *vcpu, u64 id,
case KVM_REG_PPC_IAMR:
vcpu->arch.iamr = set_reg_val(id, *val);
break;
- case KVM_REG_PPC_FSCR:
- vcpu->arch.fscr = set_reg_val(id, *val);
- break;
case KVM_REG_PPC_PSPB:
vcpu->arch.pspb = set_reg_val(id, *val);
break;
diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index 6e55934..ddc626e 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -53,6 +53,7 @@

static int kvmppc_handle_ext(struct kvm_vcpu *vcpu, unsigned int exit_nr,
ulong msr);
+static void kvmppc_giveup_fac(struct kvm_vcpu *vcpu, ulong fac);

/* Some compatibility defines */
#ifdef CONFIG_PPC_BOOK3S_32
@@ -115,6 +116,9 @@ void kvmppc_copy_to_svcpu(struct kvmppc_book3s_shadow_vcpu *svcpu,
svcpu->ctr = vcpu->arch.ctr;
svcpu->lr = vcpu->arch.lr;
svcpu->pc = vcpu->arch.pc;
+#ifdef CONFIG_PPC_BOOK3S_64
+ svcpu->shadow_fscr = vcpu->arch.shadow_fscr;
+#endif
svcpu->in_use = true;
}

@@ -158,6 +162,9 @@ void kvmppc_copy_from_svcpu(struct kvm_vcpu *vcpu,
vcpu->arch.fault_dar = svcpu->fault_dar;
vcpu->arch.fault_dsisr = svcpu->fault_dsisr;
vcpu->arch.last_inst = svcpu->last_inst;
+#ifdef CONFIG_PPC_BOOK3S_64
+ vcpu->arch.shadow_fscr = svcpu->shadow_fscr;
+#endif
svcpu->in_use = false;

out:
@@ -610,6 +617,17 @@ void kvmppc_giveup_ext(struct kvm_vcpu *vcpu, ulong msr)
kvmppc_recalc_shadow_msr(vcpu);
}

+/* Give up facility (TAR / EBB / DSCR) */
+static void kvmppc_giveup_fac(struct kvm_vcpu *vcpu, ulong fac)
+{
+#ifdef CONFIG_PPC_BOOK3S_64
+ if (!(vcpu->arch.shadow_fscr & (1ULL << fac))) {
+ /* Facility not available to the guest, ignore giveup request*/
+ return;
+ }
+#endif
+}
+
static int kvmppc_read_inst(struct kvm_vcpu *vcpu)
{
ulong srr0 = kvmppc_get_pc(vcpu);
@@ -741,6 +759,50 @@ static void kvmppc_handle_lost_ext(struct kvm_vcpu *vcpu)
current->thread.regs->msr |= lost_ext;
}

+#ifdef CONFIG_PPC_BOOK3S_64
+
+static void kvmppc_trigger_fac_interrupt(struct kvm_vcpu *vcpu, ulong fac)
+{
+ /* Inject the Interrupt Cause field and trigger a guest interrupt */
+ vcpu->arch.fscr &= ~(0xffULL << 56);
+ vcpu->arch.fscr |= (fac << 56);
+ kvmppc_book3s_queue_irqprio(vcpu, BOOK3S_INTERRUPT_FAC_UNAVAIL);
+}
+
+static void kvmppc_emulate_fac(struct kvm_vcpu *vcpu, ulong fac)
+{
+ enum emulation_result er = EMULATE_FAIL;
+
+ if (!(kvmppc_get_msr(vcpu) & MSR_PR))
+ er = kvmppc_emulate_instruction(vcpu->run, vcpu);
+
+ if ((er != EMULATE_DONE) && (er != EMULATE_AGAIN)) {
+ /* Couldn't emulate, trigger interrupt in guest */
+ kvmppc_trigger_fac_interrupt(vcpu, fac);
+ }
+}
+
+/* Enable facilities (TAR, EBB, DSCR) for the guest */
+static int kvmppc_handle_fac(struct kvm_vcpu *vcpu, ulong fac)
+{
+ BUG_ON(!cpu_has_feature(CPU_FTR_ARCH_207S));
+
+ if (!(vcpu->arch.fscr & (1ULL << fac))) {
+ /* Facility not enabled by the guest */
+ kvmppc_trigger_fac_interrupt(vcpu, fac);
+ return RESUME_GUEST;
+ }
+
+ switch (fac) {
+ default:
+ kvmppc_emulate_fac(vcpu, fac);
+ break;
+ }
+
+ return RESUME_GUEST;
+}
+#endif
+
int kvmppc_handle_exit_pr(struct kvm_run *run, struct kvm_vcpu *vcpu,
unsigned int exit_nr)
{
@@ -1015,6 +1077,12 @@ program_interrupt:
}
r = RESUME_GUEST;
break;
+#ifdef CONFIG_PPC_BOOK3S_64
+ case BOOK3S_INTERRUPT_FAC_UNAVAIL:
+ kvmppc_handle_fac(vcpu, vcpu->arch.shadow_fscr >> 56);
+ r = RESUME_GUEST;
+ break;
+#endif
case BOOK3S_INTERRUPT_MACHINE_CHECK:
case BOOK3S_INTERRUPT_TRACE:
kvmppc_book3s_queue_irqprio(vcpu, exit_nr);
diff --git a/arch/powerpc/kvm/book3s_segment.S b/arch/powerpc/kvm/book3s_segment.S
index 1e0cc2a..acee37c 100644
--- a/arch/powerpc/kvm/book3s_segment.S
+++ b/arch/powerpc/kvm/book3s_segment.S
@@ -90,6 +90,15 @@ kvmppc_handler_trampoline_enter:
LOAD_GUEST_SEGMENTS

#ifdef CONFIG_PPC_BOOK3S_64
+BEGIN_FTR_SECTION
+ /* Save host FSCR */
+ mfspr r8, SPRN_FSCR
+ std r8, HSTATE_HOST_FSCR(r13)
+ /* Set FSCR during guest execution */
+ ld r9, SVCPU_SHADOW_FSCR(r13)
+ mtspr SPRN_FSCR, r9
+END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
+
/* Some guests may need to have dcbz set to 32 byte length.
*
* Usually we ensure that by patching the guest's instructions
@@ -255,6 +264,10 @@ BEGIN_FTR_SECTION
cmpwi r12, BOOK3S_INTERRUPT_H_EMUL_ASSIST
beq- ld_last_inst
END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
+BEGIN_FTR_SECTION
+ cmpwi r12, BOOK3S_INTERRUPT_FAC_UNAVAIL
+ beq- ld_last_inst
+END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
#endif

b no_ld_last_inst
@@ -311,6 +324,18 @@ no_ld_last_inst:

no_dcbz32_off:

+BEGIN_FTR_SECTION
+ /* Save guest FSCR on a FAC_UNAVAIL interrupt */
+ cmpwi r12, BOOK3S_INTERRUPT_FAC_UNAVAIL
+ bne+ no_fscr_save
+ mfspr r7, SPRN_FSCR
+ std r7, SVCPU_SHADOW_FSCR(r13)
+no_fscr_save:
+ /* Restore host FSCR */
+ ld r8, HSTATE_HOST_FSCR(r13)
+ mtspr SPRN_FSCR, r8
+END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
+
#endif /* CONFIG_PPC_BOOK3S_64 */

/*
--
1.8.1.4