spapr: fix the value of SDR1 in kvmppc_put_books_sregs()

When running with KVM PR, if a new HPT is allocated we need to inform
KVM about the HPT address and size. This is currently done by hacking
the value of SDR1 and pushing it to KVM in several places.

Also, migration breaks the guest since it is very unlikely the HPT has
the same address in source and destination, but we push the incoming
value of SDR1 to KVM anyway.

This patch introduces a new virtual hypervisor hook so that the spapr
code can provide the correct value of SDR1 to be pushed to KVM each
time kvmppc_put_books_sregs() is called.

It allows to get rid of all the hacking in the spapr/kvmppc code and
it fixes migration of nested KVM PR.

Suggested-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 0ce3ec87ac5976eb2b44a69d293b97cf6340ec24..ff87f155d55ec3d216ed8a2f62e2ea1148d9b0e3 100644 (file)
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -1240,6 +1240,19 @@ static hwaddr spapr_hpt_mask(PPCVirtualHypervisor *vhyp)
     return HTAB_SIZE(spapr) / HASH_PTEG_SIZE_64 - 1;
 }
 
+static target_ulong spapr_encode_hpt_for_kvm_pr(PPCVirtualHypervisor *vhyp)
+{
+    sPAPRMachineState *spapr = SPAPR_MACHINE(vhyp);
+
+    assert(kvm_enabled());
+
+    if (!spapr->htab) {
+        return 0;
+    }
+
+    return (target_ulong)(uintptr_t)spapr->htab | (spapr->htab_shift - 18);
+}
+
 static const ppc_hash_pte64_t *spapr_map_hptes(PPCVirtualHypervisor *vhyp,
                                                 hwaddr ptex, int n)
 {
@@ -3604,6 +3617,7 @@ static void spapr_machine_class_init(ObjectClass *oc, void *data)
     vhc->unmap_hptes = spapr_unmap_hptes;
     vhc->store_hpte = spapr_store_hpte;
     vhc->get_patbe = spapr_get_patbe;
+    vhc->encode_hpt_for_kvm_pr = spapr_encode_hpt_for_kvm_pr;
     xic->ics_get = spapr_ics_get;
     xic->ics_resend = spapr_ics_resend;
     xic->icp_get = spapr_icp_get;

diff --git a/hw/ppc/spapr_cpu_core.c b/hw/ppc/spapr_cpu_core.c
index c08ee7571a50933807dd76c3c573a6a376251acf..3e20b1d8864417be21d0052d0b80c9ce09164fa5 100644 (file)
--- a/hw/ppc/spapr_cpu_core.c
+++ b/hw/ppc/spapr_cpu_core.c
@@ -18,6 +18,7 @@
 #include "hw/ppc/ppc.h"
 #include "target/ppc/mmu-hash64.h"
 #include "sysemu/numa.h"
+#include "sysemu/hw_accel.h"
 #include "qemu/error-report.h"
 
 void spapr_cpu_parse_features(sPAPRMachineState *spapr)
@@ -73,7 +74,6 @@ void spapr_cpu_parse_features(sPAPRMachineState *spapr)
 
 static void spapr_cpu_reset(void *opaque)
 {
-    sPAPRMachineState *spapr = SPAPR_MACHINE(qdev_get_machine());
     PowerPCCPU *cpu = opaque;
     CPUState *cs = CPU(cpu);
     CPUPPCState *env = &cpu->env;
@@ -86,20 +86,6 @@ static void spapr_cpu_reset(void *opaque)
     cs->halted = 1;
 
     env->spr[SPR_HIOR] = 0;
-
-    /*
-     * This is a hack for the benefit of KVM PR - it abuses the SDR1
-     * slot in kvm_sregs to communicate the userspace address of the
-     * HPT
-     */
-    if (kvm_enabled()) {
-        env->spr[SPR_SDR1] = (target_ulong)(uintptr_t)spapr->htab
-            | (spapr->htab_shift - 18);
-        if (kvmppc_put_books_sregs(cpu) < 0) {
-            error_report("Unable to update SDR1 in KVM");
-            exit(1);
-        }
-    }
 }
 
 static void spapr_cpu_destroy(PowerPCCPU *cpu)

diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
index 57bb411394ed00f486ebd1b2623cf4c346ff341f..8d72bb7c1c34f762394c3204b5526ff72bcda017 100644 (file)
--- a/hw/ppc/spapr_hcall.c
+++ b/hw/ppc/spapr_hcall.c
@@ -686,6 +686,37 @@ static int rehash_hpt(PowerPCCPU *cpu,
     return H_SUCCESS;
 }
 
+static void do_push_sregs_to_kvm_pr(CPUState *cs, run_on_cpu_data data)
+{
+    int ret;
+
+    cpu_synchronize_state(cs);
+
+    ret = kvmppc_put_books_sregs(POWERPC_CPU(cs));
+    if (ret < 0) {
+        error_report("failed to push sregs to KVM: %s", strerror(-ret));
+        exit(1);
+    }
+}
+
+static void push_sregs_to_kvm_pr(sPAPRMachineState *spapr)
+{
+    CPUState *cs;
+
+    /*
+     * This is a hack for the benefit of KVM PR - it abuses the SDR1
+     * slot in kvm_sregs to communicate the userspace address of the
+     * HPT
+     */
+    if (!kvm_enabled() || !spapr->htab) {
+        return;
+    }
+
+    CPU_FOREACH(cs) {
+        run_on_cpu(cs, do_push_sregs_to_kvm_pr, RUN_ON_CPU_NULL);
+    }
+}
+
 static target_ulong h_resize_hpt_commit(PowerPCCPU *cpu,
                                         sPAPRMachineState *spapr,
                                         target_ulong opcode,
@@ -733,12 +764,7 @@ static target_ulong h_resize_hpt_commit(PowerPCCPU *cpu,
         spapr->htab = pending->hpt;
         spapr->htab_shift = pending->shift;
 
-        if (kvm_enabled()) {
-            /* For KVM PR, update the HPT pointer */
-            target_ulong sdr1 = (target_ulong)(uintptr_t)spapr->htab
-                | (spapr->htab_shift - 18);
-            kvmppc_update_sdr1(sdr1);
-        }
+        push_sregs_to_kvm_pr(spapr);
 
         pending->hpt = NULL; /* so it's not free()d */
     }
@@ -1564,12 +1590,7 @@ static target_ulong h_client_architecture_support(PowerPCCPU *cpu,
              * the point this is called, nothing should have been
              * entered into the existing HPT */
             spapr_reallocate_hpt(spapr, maxshift, &error_fatal);
-            if (kvm_enabled()) {
-                /* For KVM PR, update the HPT pointer */
-                target_ulong sdr1 = (target_ulong)(uintptr_t)spapr->htab
-                    | (spapr->htab_shift - 18);
-                kvmppc_update_sdr1(sdr1);
-            }
+            push_sregs_to_kvm_pr(spapr);
         }
     }
 

diff --git a/target/ppc/cpu.h b/target/ppc/cpu.h
index c9d3ffa89bcb9c59e27e5d847cb6be83709d7fed..64aef17f6fb7a0b7ecc753e8df36d8c2875630fc 100644 (file)
--- a/target/ppc/cpu.h
+++ b/target/ppc/cpu.h
@@ -1243,6 +1243,7 @@ struct PPCVirtualHypervisorClass {
     void (*store_hpte)(PPCVirtualHypervisor *vhyp, hwaddr ptex,
                        uint64_t pte0, uint64_t pte1);
     uint64_t (*get_patbe)(PPCVirtualHypervisor *vhyp);
+    target_ulong (*encode_hpt_for_kvm_pr)(PPCVirtualHypervisor *vhyp);
 };
 
 #define TYPE_PPC_VIRTUAL_HYPERVISOR "ppc-virtual-hypervisor"

diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
index 5b281b2f1b6da6d09235dc95b1bcde81f0a3ec59..171d3d8040db02051d21e889171d2da903eced19 100644 (file)
--- a/target/ppc/kvm.c
+++ b/target/ppc/kvm.c
@@ -941,7 +941,13 @@ int kvmppc_put_books_sregs(PowerPCCPU *cpu)
 
     sregs.pvr = env->spr[SPR_PVR];
 
-    sregs.u.s.sdr1 = env->spr[SPR_SDR1];
+    if (cpu->vhyp) {
+        PPCVirtualHypervisorClass *vhc =
+            PPC_VIRTUAL_HYPERVISOR_GET_CLASS(cpu->vhyp);
+        sregs.u.s.sdr1 = vhc->encode_hpt_for_kvm_pr(cpu->vhyp);
+    } else {
+        sregs.u.s.sdr1 = env->spr[SPR_SDR1];
+    }
 
     /* Sync SLB */
 #ifdef TARGET_PPC64
@@ -2798,30 +2804,6 @@ int kvmppc_resize_hpt_commit(PowerPCCPU *cpu, target_ulong flags, int shift)
     return kvm_vm_ioctl(cs->kvm_state, KVM_PPC_RESIZE_HPT_COMMIT, &rhpt);
 }
 
-static void kvmppc_pivot_hpt_cpu(CPUState *cs, run_on_cpu_data arg)
-{
-    target_ulong sdr1 = arg.target_ptr;
-    PowerPCCPU *cpu = POWERPC_CPU(cs);
-    CPUPPCState *env = &cpu->env;
-
-    /* This is just for the benefit of PR KVM */
-    cpu_synchronize_state(cs);
-    env->spr[SPR_SDR1] = sdr1;
-    if (kvmppc_put_books_sregs(cpu) < 0) {
-        error_report("Unable to update SDR1 in KVM");
-        exit(1);
-    }
-}
-
-void kvmppc_update_sdr1(target_ulong sdr1)
-{
-    CPUState *cs;
-
-    CPU_FOREACH(cs) {
-        run_on_cpu(cs, kvmppc_pivot_hpt_cpu, RUN_ON_CPU_TARGET_PTR(sdr1));
-    }
-}
-
 /*
  * This is a helper function to detect a post migration scenario
  * in which a guest, running as KVM-HV, freezes in cpu_post_load because

diff --git a/target/ppc/kvm_ppc.h b/target/ppc/kvm_ppc.h
index 349f892631bf702b09b91c1eea3d512e73145314..d6be38ecafbddae8b4b7455add9d3ee366ae495d 100644 (file)
--- a/target/ppc/kvm_ppc.h
+++ b/target/ppc/kvm_ppc.h
@@ -67,7 +67,6 @@ PowerPCCPUClass *kvm_ppc_get_host_cpu_class(void);
 void kvmppc_check_papr_resize_hpt(Error **errp);
 int kvmppc_resize_hpt_prepare(PowerPCCPU *cpu, target_ulong flags, int shift);
 int kvmppc_resize_hpt_commit(PowerPCCPU *cpu, target_ulong flags, int shift);
-void kvmppc_update_sdr1(target_ulong sdr1);
 bool kvmppc_pvr_workaround_required(PowerPCCPU *cpu);
 
 bool kvmppc_is_mem_backend_page_size_ok(const char *obj_path);
@@ -325,11 +324,6 @@ static inline int kvmppc_resize_hpt_commit(PowerPCCPU *cpu,
     return -ENOSYS;
 }
 
-static inline void kvmppc_update_sdr1(target_ulong sdr1)
-{
-    abort();
-}
-
 #endif
 
 #ifndef CONFIG_KVM