accel/mshv: Register memory region listeners

Add memory listener hooks for the MSHV accelerator to track guest
memory regions. This enables the backend to respond to region
additions, removals and will be used to manage guest memory mappings
inside the hypervisor.

Actually registering physical memory in the hypervisor is still stubbed
out.

Signed-off-by: Magnus Kulke <magnuskulke@linux.microsoft.com>
Link: https://lore.kernel.org/r/20250916164847.77883-9-magnuskulke@linux.microsoft.com
[mshv.h/mshv_int.h split. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/accel/mshv/mem.c b/accel/mshv/mem.c
new file mode 100644 (file)
index 0000000..9889918
--- /dev/null
+++ b/accel/mshv/mem.c
@@ -0,0 +1,25 @@
+/*
+ * QEMU MSHV support
+ *
+ * Copyright Microsoft, Corp. 2025
+ *
+ * Authors:
+ *  Magnus Kulke      <magnuskulke@microsoft.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/error-report.h"
+#include "system/address-spaces.h"
+#include "system/mshv.h"
+#include "system/mshv_int.h"
+
+void mshv_set_phys_mem(MshvMemoryListener *mml, MemoryRegionSection *section,
+                       bool add)
+{
+    error_report("unimplemented");
+    abort();
+}
+

diff --git a/accel/mshv/meson.build b/accel/mshv/meson.build
index 4c03ac792195b3bb2bbbe1418307dd36f72dc6f1..8a6beb3fb1e82a3fbc28bf0f8461b6b5b9970c78 100644 (file)
--- a/accel/mshv/meson.build
+++ b/accel/mshv/meson.build
@@ -1,5 +1,6 @@
 mshv_ss = ss.source_set()
 mshv_ss.add(if_true: files(
+  'mem.c',
   'mshv-all.c'
 ))
 

diff --git a/accel/mshv/mshv-all.c b/accel/mshv/mshv-all.c
index ae12f0f58b93aec288f89343c04b8959bb8233b1..a684a366775f94f6a1754ce5245fc1264c488aee 100644 (file)
--- a/accel/mshv/mshv-all.c
+++ b/accel/mshv/mshv-all.c
@@ -49,10 +49,73 @@ bool mshv_allowed;
 
 MshvState *mshv_state;
 
+static void mem_region_add(MemoryListener *listener,
+                           MemoryRegionSection *section)
+{
+    MshvMemoryListener *mml;
+    mml = container_of(listener, MshvMemoryListener, listener);
+    memory_region_ref(section->mr);
+    mshv_set_phys_mem(mml, section, true);
+}
+
+static void mem_region_del(MemoryListener *listener,
+                           MemoryRegionSection *section)
+{
+    MshvMemoryListener *mml;
+    mml = container_of(listener, MshvMemoryListener, listener);
+    mshv_set_phys_mem(mml, section, false);
+    memory_region_unref(section->mr);
+}
+
+static MemoryListener mshv_memory_listener = {
+    .name = "mshv",
+    .priority = MEMORY_LISTENER_PRIORITY_ACCEL,
+    .region_add = mem_region_add,
+    .region_del = mem_region_del,
+};
+
+static MemoryListener mshv_io_listener = {
+    .name = "mshv", .priority = MEMORY_LISTENER_PRIORITY_DEV_BACKEND,
+    /* MSHV does not support PIO eventfd */
+};
+
+static void register_mshv_memory_listener(MshvState *s, MshvMemoryListener *mml,
+                                          AddressSpace *as, int as_id,
+                                          const char *name)
+{
+    int i;
+
+    mml->listener = mshv_memory_listener;
+    mml->listener.name = name;
+    memory_listener_register(&mml->listener, as);
+    for (i = 0; i < s->nr_as; ++i) {
+        if (!s->as[i].as) {
+            s->as[i].as = as;
+            s->as[i].ml = mml;
+            break;
+        }
+    }
+}
+
 static int mshv_init(AccelState *as, MachineState *ms)
 {
-    error_report("unimplemented");
-    abort();
+    MshvState *s;
+    s = MSHV_STATE(as);
+
+    accel_blocker_init();
+
+    s->vm = 0;
+
+    s->nr_as = 1;
+    s->as = g_new0(MshvAddressSpace, s->nr_as);
+
+    mshv_state = s;
+
+    register_mshv_memory_listener(s, &s->memory_listener, &address_space_memory,
+                                  0, "mshv-memory");
+    memory_listener_register(&mshv_io_listener, &address_space_io);
+
+    return 0;
 }
 
 static void mshv_start_vcpu_thread(CPUState *cpu)

diff --git a/include/system/mshv_int.h b/include/system/mshv_int.h
index 132491b599d96df053241be04be7b2bc02f7bb54..cfa177ff72f9edb4efbbd29cebd6d76224b4b476 100644 (file)
--- a/include/system/mshv_int.h
+++ b/include/system/mshv_int.h
@@ -38,4 +38,8 @@ struct MshvState {
     MshvAddressSpace *as;
 };
 
+/* memory */
+void mshv_set_phys_mem(MshvMemoryListener *mml, MemoryRegionSection *section,
+                       bool add);
+
 #endif