#include <linux/of.h>
#include <asm/reg.h>
+#include <asm/ppc-opcode.h>
+#include <asm/disassemble.h>
#include <asm/cputable.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
int thr;
struct kvmppc_vcore *vc;
+ if (vcpu->arch.doorbell_request)
+ return true;
+ /*
+ * Ensure that the read of vcore->dpdes comes after the read
+ * of vcpu->doorbell_request. This barrier matches the
+ * lwsync in book3s_hv_rmhandlers.S just before the
+ * fast_guest_return label.
+ */
+ smp_rmb();
vc = vcpu->arch.vcore;
thr = vcpu->vcpu_id - vc->first_vcpuid;
return !!(vc->dpdes & (1 << thr));
}
}
+static void do_nothing(void *x)
+{
+}
+
+static unsigned long kvmppc_read_dpdes(struct kvm_vcpu *vcpu)
+{
+ int thr, cpu, pcpu, nthreads;
+ struct kvm_vcpu *v;
+ unsigned long dpdes;
+
+ nthreads = vcpu->kvm->arch.emul_smt_mode;
+ dpdes = 0;
+ cpu = vcpu->vcpu_id & ~(nthreads - 1);
+ for (thr = 0; thr < nthreads; ++thr, ++cpu) {
+ v = kvmppc_find_vcpu(vcpu->kvm, cpu);
+ if (!v)
+ continue;
+ /*
+ * If the vcpu is currently running on a physical cpu thread,
+ * interrupt it in order to pull it out of the guest briefly,
+ * which will update its vcore->dpdes value.
+ */
+ pcpu = READ_ONCE(v->cpu);
+ if (pcpu >= 0)
+ smp_call_function_single(pcpu, do_nothing, NULL, 1);
+ if (kvmppc_doorbell_pending(v))
+ dpdes |= 1 << thr;
+ }
+ return dpdes;
+}
+
+/*
+ * On POWER9, emulate doorbell-related instructions in order to
+ * give the guest the illusion of running on a multi-threaded core.
+ * The instructions emulated are msgsndp, msgclrp, mfspr TIR,
+ * and mfspr DPDES.
+ */
+static int kvmppc_emulate_doorbell_instr(struct kvm_vcpu *vcpu)
+{
+ u32 inst, rb, thr;
+ unsigned long arg;
+ struct kvm *kvm = vcpu->kvm;
+ struct kvm_vcpu *tvcpu;
+
+ if (!cpu_has_feature(CPU_FTR_ARCH_300))
+ return EMULATE_FAIL;
+ if (kvmppc_get_last_inst(vcpu, INST_GENERIC, &inst) != EMULATE_DONE)
+ return RESUME_GUEST;
+ if (get_op(inst) != 31)
+ return EMULATE_FAIL;
+ rb = get_rb(inst);
+ thr = vcpu->vcpu_id & (kvm->arch.emul_smt_mode - 1);
+ switch (get_xop(inst)) {
+ case OP_31_XOP_MSGSNDP:
+ arg = kvmppc_get_gpr(vcpu, rb);
+ if (((arg >> 27) & 0xf) != PPC_DBELL_SERVER)
+ break;
+ arg &= 0x3f;
+ if (arg >= kvm->arch.emul_smt_mode)
+ break;
+ tvcpu = kvmppc_find_vcpu(kvm, vcpu->vcpu_id - thr + arg);
+ if (!tvcpu)
+ break;
+ if (!tvcpu->arch.doorbell_request) {
+ tvcpu->arch.doorbell_request = 1;
+ kvmppc_fast_vcpu_kick_hv(tvcpu);
+ }
+ break;
+ case OP_31_XOP_MSGCLRP:
+ arg = kvmppc_get_gpr(vcpu, rb);
+ if (((arg >> 27) & 0xf) != PPC_DBELL_SERVER)
+ break;
+ vcpu->arch.vcore->dpdes = 0;
+ vcpu->arch.doorbell_request = 0;
+ break;
+ case OP_31_XOP_MFSPR:
+ switch (get_sprn(inst)) {
+ case SPRN_TIR:
+ arg = thr;
+ break;
+ case SPRN_DPDES:
+ arg = kvmppc_read_dpdes(vcpu);
+ break;
+ default:
+ return EMULATE_FAIL;
+ }
+ kvmppc_set_gpr(vcpu, get_rt(inst), arg);
+ break;
+ default:
+ return EMULATE_FAIL;
+ }
+ kvmppc_set_pc(vcpu, kvmppc_get_pc(vcpu) + 4);
+ return RESUME_GUEST;
+}
+
static int kvmppc_handle_exit_hv(struct kvm_run *run, struct kvm_vcpu *vcpu,
struct task_struct *tsk)
{
break;
/*
* This occurs if the guest (kernel or userspace), does something that
- * is prohibited by HFSCR. We just generate a program interrupt to
- * the guest.
+ * is prohibited by HFSCR.
+ * On POWER9, this could be a doorbell instruction that we need
+ * to emulate.
+ * Otherwise, we just generate a program interrupt to the guest.
*/
case BOOK3S_INTERRUPT_H_FAC_UNAVAIL:
- kvmppc_core_queue_program(vcpu, SRR1_PROGILL);
- r = RESUME_GUEST;
+ r = EMULATE_FAIL;
+ if ((vcpu->arch.hfscr >> 56) == FSCR_MSGP_LG)
+ r = kvmppc_emulate_doorbell_instr(vcpu);
+ if (r == EMULATE_FAIL) {
+ kvmppc_core_queue_program(vcpu, SRR1_PROGILL);
+ r = RESUME_GUEST;
+ }
break;
case BOOK3S_INTERRUPT_HV_RM_HARD:
r = RESUME_PASSTHROUGH;
* This value is only used on POWER9.
* On POWER9 DD1, TM doesn't work, so we make sure to
* prevent the guest from using it.
+ * On POWER9, we want to virtualize the doorbell facility, so we
+ * turn off the HFSCR bit, which causes those instructions to trap.
*/
vcpu->arch.hfscr = mfspr(SPRN_HFSCR);
if (!cpu_has_feature(CPU_FTR_TM))
vcpu->arch.hfscr &= ~HFSCR_TM;
+ if (cpu_has_feature(CPU_FTR_ARCH_300))
+ vcpu->arch.hfscr &= ~HFSCR_MSGP;
kvmppc_mmu_book3s_hv_init(vcpu);
unsigned long flags)
{
int err;
+ int esmt = 0;
if (flags)
return -EINVAL;
* On POWER9, the threading mode is "loose",
* so each vcpu gets its own vcore.
*/
+ esmt = smt_mode;
smt_mode = 1;
}
mutex_lock(&kvm->lock);
err = -EBUSY;
if (!kvm->arch.online_vcores) {
kvm->arch.smt_mode = smt_mode;
+ kvm->arch.emul_smt_mode = esmt;
err = 0;
}
mutex_unlock(&kvm->lock);
tpaca->kvm_hstate.kvm_split_mode = NULL;
}
-static void do_nothing(void *x)
-{
-}
-
static void radix_flush_cpu(struct kvm *kvm, int cpu, struct kvm_vcpu *vcpu)
{
int i;
kvm->arch.smt_mode = threads_per_subcore;
else
kvm->arch.smt_mode = 1;
+ kvm->arch.emul_smt_mode = 1;
/*
* Create a debugfs directory for the VM
projects / linux.git / commitdiff