5 files changed, 31 insertions, 30 deletions

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 70b150b098..0d032a1ad0 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -3192,11 +3192,13 @@ static void spapr_memory_pre_plug(HotplugHandler *hotplug_dev, DeviceState *dev,
                                   Error **errp)
 {
     const sPAPRMachineClass *smc = SPAPR_MACHINE_GET_CLASS(hotplug_dev);
+    sPAPRMachineState *spapr = SPAPR_MACHINE(hotplug_dev);
     PCDIMMDevice *dimm = PC_DIMM(dev);
     PCDIMMDeviceClass *ddc = PC_DIMM_GET_CLASS(dimm);
     MemoryRegion *mr;
     uint64_t size;
-    char *mem_dev;
+    Object *memdev;
+    hwaddr pagesize;
 
     if (!smc->dr_lmb_enabled) {
         error_setg(errp, "Memory hotplug not supported for this machine");
@@ -3215,15 +3217,10 @@ static void spapr_memory_pre_plug(HotplugHandler *hotplug_dev, DeviceState *dev,
         return;
     }
 
-    mem_dev = object_property_get_str(OBJECT(dimm), PC_DIMM_MEMDEV_PROP, NULL);
-    if (mem_dev && !kvmppc_is_mem_backend_page_size_ok(mem_dev)) {
-        error_setg(errp, "Memory backend has bad page size. "
-                   "Use 'memory-backend-file' with correct mem-path.");
-        goto out;
-    }
-
-out:
-    g_free(mem_dev);
+    memdev = object_property_get_link(OBJECT(dimm), PC_DIMM_MEMDEV_PROP,
+                                      &error_abort);
+    pagesize = host_memory_backend_pagesize(MEMORY_BACKEND(memdev));
+    spapr_check_pagesize(spapr, pagesize, errp);
 }
 
 struct sPAPRDIMMState {
diff --git a/hw/ppc/spapr_caps.c b/hw/ppc/spapr_caps.c
index 6cdc0c94e7..722b213d9a 100644
--- a/hw/ppc/spapr_caps.c
+++ b/hw/ppc/spapr_caps.c
@@ -26,6 +26,7 @@
 #include "qapi/error.h"
 #include "qapi/visitor.h"
 #include "sysemu/hw_accel.h"
+#include "exec/ram_addr.h"
 #include "target/ppc/cpu.h"
 #include "target/ppc/mmu-hash64.h"
 #include "cpu-models.h"
@@ -304,14 +305,34 @@ static void cap_safe_indirect_branch_apply(sPAPRMachineState *spapr,
 
 #define VALUE_DESC_TRISTATE     " (broken, workaround, fixed)"
 
+void spapr_check_pagesize(sPAPRMachineState *spapr, hwaddr pagesize,
+                          Error **errp)
+{
+    hwaddr maxpagesize = (1ULL << spapr->eff.caps[SPAPR_CAP_HPT_MAXPAGESIZE]);
+
+    if (!kvmppc_hpt_needs_host_contiguous_pages()) {
+        return;
+    }
+
+    if (maxpagesize > pagesize) {
+        error_setg(errp,
+                   "Can't support %"HWADDR_PRIu" kiB guest pages with %"
+                   HWADDR_PRIu" kiB host pages with this KVM implementation",
+                   maxpagesize >> 10, pagesize >> 10);
+    }
+}
+
 static void cap_hpt_maxpagesize_apply(sPAPRMachineState *spapr,
                                       uint8_t val, Error **errp)
 {
     if (val < 12) {
         error_setg(errp, "Require at least 4kiB hpt-max-page-size");
+        return;
     } else if (val < 16) {
         warn_report("Many guests require at least 64kiB hpt-max-page-size");
     }
+
+    spapr_check_pagesize(spapr, qemu_getrampagesize(), errp);
 }
 
 sPAPRCapabilityInfo capability_table[SPAPR_CAP_NUM] = {
diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
index 4bc9dbff96..7e028164ba 100644
--- a/include/hw/ppc/spapr.h
+++ b/include/hw/ppc/spapr.h
@@ -806,4 +806,7 @@ void spapr_caps_cpu_apply(sPAPRMachineState *spapr, PowerPCCPU *cpu);
 void spapr_caps_add_properties(sPAPRMachineClass *smc, Error **errp);
 int spapr_caps_post_migration(sPAPRMachineState *spapr);
 
+void spapr_check_pagesize(sPAPRMachineState *spapr, hwaddr pagesize,
+                          Error **errp);
+
 #endif /* HW_SPAPR_H */
diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
index 50b5d01432..9cfbd388ad 100644
--- a/target/ppc/kvm.c
+++ b/target/ppc/kvm.c
@@ -500,26 +500,12 @@ static void kvm_fixup_page_sizes(PowerPCCPU *cpu)
         cpu->hash64_opts->flags &= ~PPC_HASH64_1TSEG;
     }
 }
-
-bool kvmppc_is_mem_backend_page_size_ok(const char *obj_path)
-{
-    Object *mem_obj = object_resolve_path(obj_path, NULL);
-    long pagesize = host_memory_backend_pagesize(MEMORY_BACKEND(mem_obj));
-
-    return pagesize >= max_cpu_page_size;
-}
-
 #else /* defined (TARGET_PPC64) */
 
 static inline void kvm_fixup_page_sizes(PowerPCCPU *cpu)
 {
 }
 
-bool kvmppc_is_mem_backend_page_size_ok(const char *obj_path)
-{
-    return true;
-}
-
 #endif /* !defined (TARGET_PPC64) */
 
 unsigned long kvm_arch_vcpu_id(CPUState *cpu)
diff --git a/target/ppc/kvm_ppc.h b/target/ppc/kvm_ppc.h
index a7ddb8a5d6..443fca0a4e 100644
--- a/target/ppc/kvm_ppc.h
+++ b/target/ppc/kvm_ppc.h
@@ -71,7 +71,6 @@ int kvmppc_resize_hpt_commit(PowerPCCPU *cpu, target_ulong flags, int shift);
 bool kvmppc_pvr_workaround_required(PowerPCCPU *cpu);
 
 bool kvmppc_hpt_needs_host_contiguous_pages(void);
-bool kvmppc_is_mem_backend_page_size_ok(const char *obj_path);
 
 #else
 
@@ -228,11 +227,6 @@ static inline bool kvmppc_hpt_needs_host_contiguous_pages(void)
     return false;
 }
 
-static inline bool kvmppc_is_mem_backend_page_size_ok(const char *obj_path)
-{
-    return true;
-}
-
 static inline bool kvmppc_has_cap_spapr_vfio(void)
 {
     return false;