3 files changed, 374 insertions, 10 deletions

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 51ba8615f2..f0b75b22bb 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -1270,6 +1270,8 @@ static void emulate_spapr_hypercall(PPCVirtualHypervisor *vhyp,
     /* The TCG path should also be holding the BQL at this point */
     g_assert(qemu_mutex_iothread_locked());
 
+    g_assert(!vhyp_cpu_in_nested(cpu));
+
     if (msr_pr) {
         hcall_dprintf("Hypercall made with MSR[PR]=1\n");
         env->gpr[3] = H_PRIVILEGE;
@@ -1313,12 +1315,34 @@ static bool spapr_get_pate(PPCVirtualHypervisor *vhyp, PowerPCCPU *cpu,
                            target_ulong lpid, ppc_v3_pate_t *entry)
 {
     SpaprMachineState *spapr = SPAPR_MACHINE(vhyp);
+    SpaprCpuState *spapr_cpu = spapr_cpu_state(cpu);
 
-    assert(lpid == 0);
+    if (!spapr_cpu->in_nested) {
+        assert(lpid == 0);
 
-    /* Copy PATE1:GR into PATE0:HR */
-    entry->dw0 = spapr->patb_entry & PATE0_HR;
-    entry->dw1 = spapr->patb_entry;
+        /* Copy PATE1:GR into PATE0:HR */
+        entry->dw0 = spapr->patb_entry & PATE0_HR;
+        entry->dw1 = spapr->patb_entry;
+
+    } else {
+        uint64_t patb, pats;
+
+        assert(lpid != 0);
+
+        patb = spapr->nested_ptcr & PTCR_PATB;
+        pats = spapr->nested_ptcr & PTCR_PATS;
+
+        /* Calculate number of entries */
+        pats = 1ull << (pats + 12 - 4);
+        if (pats <= lpid) {
+            return false;
+        }
+
+        /* Grab entry */
+        patb += 16 * lpid;
+        entry->dw0 = ldq_phys(CPU(cpu)->as, patb);
+        entry->dw1 = ldq_phys(CPU(cpu)->as, patb + 8);
+    }
 
     return true;
 }
@@ -4474,7 +4498,9 @@ PowerPCCPU *spapr_find_cpu(int vcpu_id)
 
 static bool spapr_cpu_in_nested(PowerPCCPU *cpu)
 {
-    return false;
+    SpaprCpuState *spapr_cpu = spapr_cpu_state(cpu);
+
+    return spapr_cpu->in_nested;
 }
 
 static void spapr_cpu_exec_enter(PPCVirtualHypervisor *vhyp, PowerPCCPU *cpu)
@@ -4586,6 +4612,7 @@ static void spapr_machine_class_init(ObjectClass *oc, void *data)
     nc->nmi_monitor_handler = spapr_nmi;
     smc->phb_placement = spapr_phb_placement;
     vhc->cpu_in_nested = spapr_cpu_in_nested;
+    vhc->deliver_hv_excp = spapr_exit_nested;
     vhc->hypercall = emulate_spapr_hypercall;
     vhc->hpt_mask = spapr_hpt_mask;
     vhc->map_hptes = spapr_map_hptes;
diff --git a/hw/ppc/spapr_caps.c b/hw/ppc/spapr_caps.c
index ed7c077a0d..6167431271 100644
--- a/hw/ppc/spapr_caps.c
+++ b/hw/ppc/spapr_caps.c
@@ -444,19 +444,23 @@ static void cap_nested_kvm_hv_apply(SpaprMachineState *spapr,
 {
     ERRP_GUARD();
     PowerPCCPU *cpu = POWERPC_CPU(first_cpu);
+    CPUPPCState *env = &cpu->env;
 
     if (!val) {
         /* capability disabled by default */
         return;
     }
 
-    if (tcg_enabled()) {
-        error_setg(errp, "No Nested KVM-HV support in TCG");
+    if (!(env->insns_flags2 & PPC2_ISA300)) {
+        error_setg(errp, "Nested-HV only supported on POWER9 and later");
         error_append_hint(errp, "Try appending -machine cap-nested-hv=off\n");
-    } else if (kvm_enabled()) {
+        return;
+    }
+
+    if (kvm_enabled()) {
         if (!ppc_check_compat(cpu, CPU_POWERPC_LOGICAL_3_00, 0,
                               spapr->max_compat_pvr)) {
-            error_setg(errp, "Nested KVM-HV only supported on POWER9");
+            error_setg(errp, "Nested-HV only supported on POWER9 and later");
             error_append_hint(errp,
                               "Try appending -machine max-cpu-compat=power9\n");
             return;
@@ -464,7 +468,7 @@ static void cap_nested_kvm_hv_apply(SpaprMachineState *spapr,
 
         if (!kvmppc_has_cap_nested_kvm_hv()) {
             error_setg(errp,
-                       "KVM implementation does not support Nested KVM-HV");
+                       "KVM implementation does not support Nested-HV");
             error_append_hint(errp,
                               "Try appending -machine cap-nested-hv=off\n");
         } else if (kvmppc_set_cap_nested_kvm_hv(val) < 0) {
diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
index 222c1b6bbd..f008290787 100644
--- a/hw/ppc/spapr_hcall.c
+++ b/hw/ppc/spapr_hcall.c
@@ -9,6 +9,7 @@
 #include "qemu/error-report.h"
 #include "exec/exec-all.h"
 #include "helper_regs.h"
+#include "hw/ppc/ppc.h"
 #include "hw/ppc/spapr.h"
 #include "hw/ppc/spapr_cpu_core.h"
 #include "mmu-hash64.h"
@@ -1497,6 +1498,333 @@ static void hypercall_register_softmmu(void)
 }
 #endif
 
+/* TCG only */
+#define PRTS_MASK      0x1f
+
+static target_ulong h_set_ptbl(PowerPCCPU *cpu,
+                               SpaprMachineState *spapr,
+                               target_ulong opcode,
+                               target_ulong *args)
+{
+    target_ulong ptcr = args[0];
+
+    if (!spapr_get_cap(spapr, SPAPR_CAP_NESTED_KVM_HV)) {
+        return H_FUNCTION;
+    }
+
+    if ((ptcr & PRTS_MASK) + 12 - 4 > 12) {
+        return H_PARAMETER;
+    }
+
+    spapr->nested_ptcr = ptcr; /* Save new partition table */
+
+    return H_SUCCESS;
+}
+
+static target_ulong h_tlb_invalidate(PowerPCCPU *cpu,
+                                     SpaprMachineState *spapr,
+                                     target_ulong opcode,
+                                     target_ulong *args)
+{
+    /*
+     * The spapr virtual hypervisor nested HV implementation retains no L2
+     * translation state except for TLB. And the TLB is always invalidated
+     * across L1<->L2 transitions, so nothing is required here.
+     */
+
+    return H_SUCCESS;
+}
+
+static target_ulong h_copy_tofrom_guest(PowerPCCPU *cpu,
+                                        SpaprMachineState *spapr,
+                                        target_ulong opcode,
+                                        target_ulong *args)
+{
+    /*
+     * This HCALL is not required, L1 KVM will take a slow path and walk the
+     * page tables manually to do the data copy.
+     */
+    return H_FUNCTION;
+}
+
+/*
+ * When this handler returns, the environment is switched to the L2 guest
+ * and TCG begins running that. spapr_exit_nested() performs the switch from
+ * L2 back to L1 and returns from the H_ENTER_NESTED hcall.
+ */
+static target_ulong h_enter_nested(PowerPCCPU *cpu,
+                                   SpaprMachineState *spapr,
+                                   target_ulong opcode,
+                                   target_ulong *args)
+{
+    PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cpu);
+    CPUState *cs = CPU(cpu);
+    CPUPPCState *env = &cpu->env;
+    SpaprCpuState *spapr_cpu = spapr_cpu_state(cpu);
+    target_ulong hv_ptr = args[0];
+    target_ulong regs_ptr = args[1];
+    target_ulong hdec, now = cpu_ppc_load_tbl(env);
+    target_ulong lpcr, lpcr_mask;
+    struct kvmppc_hv_guest_state *hvstate;
+    struct kvmppc_hv_guest_state hv_state;
+    struct kvmppc_pt_regs *regs;
+    hwaddr len;
+    uint64_t cr;
+    int i;
+
+    if (spapr->nested_ptcr == 0) {
+        return H_NOT_AVAILABLE;
+    }
+
+    len = sizeof(*hvstate);
+    hvstate = address_space_map(CPU(cpu)->as, hv_ptr, &len, false,
+                                MEMTXATTRS_UNSPECIFIED);
+    if (len != sizeof(*hvstate)) {
+        address_space_unmap(CPU(cpu)->as, hvstate, len, 0, false);
+        return H_PARAMETER;
+    }
+
+    memcpy(&hv_state, hvstate, len);
+
+    address_space_unmap(CPU(cpu)->as, hvstate, len, len, false);
+
+    /*
+     * We accept versions 1 and 2. Version 2 fields are unused because TCG
+     * does not implement DAWR*.
+     */
+    if (hv_state.version > HV_GUEST_STATE_VERSION) {
+        return H_PARAMETER;
+    }
+
+    spapr_cpu->nested_host_state = g_try_malloc(sizeof(CPUPPCState));
+    if (!spapr_cpu->nested_host_state) {
+        return H_NO_MEM;
+    }
+
+    memcpy(spapr_cpu->nested_host_state, env, sizeof(CPUPPCState));
+
+    len = sizeof(*regs);
+    regs = address_space_map(CPU(cpu)->as, regs_ptr, &len, false,
+                                MEMTXATTRS_UNSPECIFIED);
+    if (!regs || len != sizeof(*regs)) {
+        address_space_unmap(CPU(cpu)->as, regs, len, 0, false);
+        g_free(spapr_cpu->nested_host_state);
+        return H_P2;
+    }
+
+    len = sizeof(env->gpr);
+    assert(len == sizeof(regs->gpr));
+    memcpy(env->gpr, regs->gpr, len);
+
+    env->lr = regs->link;
+    env->ctr = regs->ctr;
+    cpu_write_xer(env, regs->xer);
+
+    cr = regs->ccr;
+    for (i = 7; i >= 0; i--) {
+        env->crf[i] = cr & 15;
+        cr >>= 4;
+    }
+
+    env->msr = regs->msr;
+    env->nip = regs->nip;
+
+    address_space_unmap(CPU(cpu)->as, regs, len, len, false);
+
+    env->cfar = hv_state.cfar;
+
+    assert(env->spr[SPR_LPIDR] == 0);
+    env->spr[SPR_LPIDR] = hv_state.lpid;
+
+    lpcr_mask = LPCR_DPFD | LPCR_ILE | LPCR_AIL | LPCR_LD | LPCR_MER;
+    lpcr = (env->spr[SPR_LPCR] & ~lpcr_mask) | (hv_state.lpcr & lpcr_mask);
+    lpcr |= LPCR_HR | LPCR_UPRT | LPCR_GTSE | LPCR_HVICE | LPCR_HDICE;
+    lpcr &= ~LPCR_LPES0;
+    env->spr[SPR_LPCR] = lpcr & pcc->lpcr_mask;
+
+    env->spr[SPR_PCR] = hv_state.pcr;
+    /* hv_state.amor is not used */
+    env->spr[SPR_DPDES] = hv_state.dpdes;
+    env->spr[SPR_HFSCR] = hv_state.hfscr;
+    hdec = hv_state.hdec_expiry - now;
+    spapr_cpu->nested_tb_offset = hv_state.tb_offset;
+    /* TCG does not implement DAWR*, CIABR, PURR, SPURR, IC, VTB, HEIR SPRs*/
+    env->spr[SPR_SRR0] = hv_state.srr0;
+    env->spr[SPR_SRR1] = hv_state.srr1;
+    env->spr[SPR_SPRG0] = hv_state.sprg[0];
+    env->spr[SPR_SPRG1] = hv_state.sprg[1];
+    env->spr[SPR_SPRG2] = hv_state.sprg[2];
+    env->spr[SPR_SPRG3] = hv_state.sprg[3];
+    env->spr[SPR_BOOKS_PID] = hv_state.pidr;
+    env->spr[SPR_PPR] = hv_state.ppr;
+
+    cpu_ppc_hdecr_init(env);
+    cpu_ppc_store_hdecr(env, hdec);
+
+    /*
+     * The hv_state.vcpu_token is not needed. It is used by the KVM
+     * implementation to remember which L2 vCPU last ran on which physical
+     * CPU so as to invalidate process scope translations if it is moved
+     * between physical CPUs. For now TLBs are always flushed on L1<->L2
+     * transitions so this is not a problem.
+     *
+     * Could validate that the same vcpu_token does not attempt to run on
+     * different L1 vCPUs at the same time, but that would be a L1 KVM bug
+     * and it's not obviously worth a new data structure to do it.
+     */
+
+    env->tb_env->tb_offset += spapr_cpu->nested_tb_offset;
+    spapr_cpu->in_nested = true;
+
+    hreg_compute_hflags(env);
+    tlb_flush(cs);
+    env->reserve_addr = -1; /* Reset the reservation */
+
+    /*
+     * The spapr hcall helper sets env->gpr[3] to the return value, but at
+     * this point the L1 is not returning from the hcall but rather we
+     * start running the L2, so r3 must not be clobbered, so return env->gpr[3]
+     * to leave it unchanged.
+     */
+    return env->gpr[3];
+}
+
+void spapr_exit_nested(PowerPCCPU *cpu, int excp)
+{
+    CPUState *cs = CPU(cpu);
+    CPUPPCState *env = &cpu->env;
+    SpaprCpuState *spapr_cpu = spapr_cpu_state(cpu);
+    target_ulong r3_return = env->excp_vectors[excp]; /* hcall return value */
+    target_ulong hv_ptr = spapr_cpu->nested_host_state->gpr[4];
+    target_ulong regs_ptr = spapr_cpu->nested_host_state->gpr[5];
+    struct kvmppc_hv_guest_state *hvstate;
+    struct kvmppc_pt_regs *regs;
+    hwaddr len;
+    uint64_t cr;
+    int i;
+
+    assert(spapr_cpu->in_nested);
+
+    cpu_ppc_hdecr_exit(env);
+
+    len = sizeof(*hvstate);
+    hvstate = address_space_map(CPU(cpu)->as, hv_ptr, &len, true,
+                                MEMTXATTRS_UNSPECIFIED);
+    if (len != sizeof(*hvstate)) {
+        address_space_unmap(CPU(cpu)->as, hvstate, len, 0, true);
+        r3_return = H_PARAMETER;
+        goto out_restore_l1;
+    }
+
+    hvstate->cfar = env->cfar;
+    hvstate->lpcr = env->spr[SPR_LPCR];
+    hvstate->pcr = env->spr[SPR_PCR];
+    hvstate->dpdes = env->spr[SPR_DPDES];
+    hvstate->hfscr = env->spr[SPR_HFSCR];
+
+    if (excp == POWERPC_EXCP_HDSI) {
+        hvstate->hdar = env->spr[SPR_HDAR];
+        hvstate->hdsisr = env->spr[SPR_HDSISR];
+        hvstate->asdr = env->spr[SPR_ASDR];
+    } else if (excp == POWERPC_EXCP_HISI) {
+        hvstate->asdr = env->spr[SPR_ASDR];
+    }
+
+    /* HEIR should be implemented for HV mode and saved here. */
+    hvstate->srr0 = env->spr[SPR_SRR0];
+    hvstate->srr1 = env->spr[SPR_SRR1];
+    hvstate->sprg[0] = env->spr[SPR_SPRG0];
+    hvstate->sprg[1] = env->spr[SPR_SPRG1];
+    hvstate->sprg[2] = env->spr[SPR_SPRG2];
+    hvstate->sprg[3] = env->spr[SPR_SPRG3];
+    hvstate->pidr = env->spr[SPR_BOOKS_PID];
+    hvstate->ppr = env->spr[SPR_PPR];
+
+    /* Is it okay to specify write length larger than actual data written? */
+    address_space_unmap(CPU(cpu)->as, hvstate, len, len, true);
+
+    len = sizeof(*regs);
+    regs = address_space_map(CPU(cpu)->as, regs_ptr, &len, true,
+                                MEMTXATTRS_UNSPECIFIED);
+    if (!regs || len != sizeof(*regs)) {
+        address_space_unmap(CPU(cpu)->as, regs, len, 0, true);
+        r3_return = H_P2;
+        goto out_restore_l1;
+    }
+
+    len = sizeof(env->gpr);
+    assert(len == sizeof(regs->gpr));
+    memcpy(regs->gpr, env->gpr, len);
+
+    regs->link = env->lr;
+    regs->ctr = env->ctr;
+    regs->xer = cpu_read_xer(env);
+
+    cr = 0;
+    for (i = 0; i < 8; i++) {
+        cr |= (env->crf[i] & 15) << (4 * (7 - i));
+    }
+    regs->ccr = cr;
+
+    if (excp == POWERPC_EXCP_MCHECK ||
+        excp == POWERPC_EXCP_RESET ||
+        excp == POWERPC_EXCP_SYSCALL) {
+        regs->nip = env->spr[SPR_SRR0];
+        regs->msr = env->spr[SPR_SRR1] & env->msr_mask;
+    } else {
+        regs->nip = env->spr[SPR_HSRR0];
+        regs->msr = env->spr[SPR_HSRR1] & env->msr_mask;
+    }
+
+    /* Is it okay to specify write length larger than actual data written? */
+    address_space_unmap(CPU(cpu)->as, regs, len, len, true);
+
+out_restore_l1:
+    memcpy(env->gpr, spapr_cpu->nested_host_state->gpr, sizeof(env->gpr));
+    env->lr = spapr_cpu->nested_host_state->lr;
+    env->ctr = spapr_cpu->nested_host_state->ctr;
+    memcpy(env->crf, spapr_cpu->nested_host_state->crf, sizeof(env->crf));
+    env->cfar = spapr_cpu->nested_host_state->cfar;
+    env->xer = spapr_cpu->nested_host_state->xer;
+    env->so = spapr_cpu->nested_host_state->so;
+    env->ov = spapr_cpu->nested_host_state->ov;
+    env->ov32 = spapr_cpu->nested_host_state->ov32;
+    env->ca32 = spapr_cpu->nested_host_state->ca32;
+    env->msr = spapr_cpu->nested_host_state->msr;
+    env->nip = spapr_cpu->nested_host_state->nip;
+
+    assert(env->spr[SPR_LPIDR] != 0);
+    env->spr[SPR_LPCR] = spapr_cpu->nested_host_state->spr[SPR_LPCR];
+    env->spr[SPR_LPIDR] = spapr_cpu->nested_host_state->spr[SPR_LPIDR];
+    env->spr[SPR_PCR] = spapr_cpu->nested_host_state->spr[SPR_PCR];
+    env->spr[SPR_DPDES] = 0;
+    env->spr[SPR_HFSCR] = spapr_cpu->nested_host_state->spr[SPR_HFSCR];
+    env->spr[SPR_SRR0] = spapr_cpu->nested_host_state->spr[SPR_SRR0];
+    env->spr[SPR_SRR1] = spapr_cpu->nested_host_state->spr[SPR_SRR1];
+    env->spr[SPR_SPRG0] = spapr_cpu->nested_host_state->spr[SPR_SPRG0];
+    env->spr[SPR_SPRG1] = spapr_cpu->nested_host_state->spr[SPR_SPRG1];
+    env->spr[SPR_SPRG2] = spapr_cpu->nested_host_state->spr[SPR_SPRG2];
+    env->spr[SPR_SPRG3] = spapr_cpu->nested_host_state->spr[SPR_SPRG3];
+    env->spr[SPR_BOOKS_PID] = spapr_cpu->nested_host_state->spr[SPR_BOOKS_PID];
+    env->spr[SPR_PPR] = spapr_cpu->nested_host_state->spr[SPR_PPR];
+
+    /*
+     * Return the interrupt vector address from H_ENTER_NESTED to the L1
+     * (or error code).
+     */
+    env->gpr[3] = r3_return;
+
+    env->tb_env->tb_offset -= spapr_cpu->nested_tb_offset;
+    spapr_cpu->in_nested = false;
+
+    hreg_compute_hflags(env);
+    tlb_flush(cs);
+    env->reserve_addr = -1; /* Reset the reservation */
+
+    g_free(spapr_cpu->nested_host_state);
+    spapr_cpu->nested_host_state = NULL;
+}
+
 static void hypercall_register_types(void)
 {
     hypercall_register_softmmu();
@@ -1552,6 +1880,11 @@ static void hypercall_register_types(void)
     spapr_register_hypercall(KVMPPC_H_CAS, h_client_architecture_support);
 
     spapr_register_hypercall(KVMPPC_H_UPDATE_DT, h_update_dt);
+
+    spapr_register_hypercall(KVMPPC_H_SET_PARTITION_TABLE, h_set_ptbl);
+    spapr_register_hypercall(KVMPPC_H_ENTER_NESTED, h_enter_nested);
+    spapr_register_hypercall(KVMPPC_H_TLB_INVALIDATE, h_tlb_invalidate);
+    spapr_register_hypercall(KVMPPC_H_COPY_TOFROM_GUEST, h_copy_tofrom_guest);
 }
 
 type_init(hypercall_register_types)