Merge tag 'mem-2024-12-21' of https://github.com/davidhildenbrand/qemu into staging

Hi,

"Host Memory Backends" and "Memory devices" queue ("mem"):
- Fixup handling of virtio-mem unplug during system resets, as
  preparation for s390x support (especially kdump in the Linux guest)
- virtio-mem support for s390x

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 # gpg:                using RSA key 1BD9CAAD735C4C3A460DFCCA4DDE10F700FF835A
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 # gpg: Good signature from "David Hildenbrand <[email protected]>" [unknown]
 # gpg:                 aka "David Hildenbrand <[email protected]>" [full]
 # gpg:                 aka "David Hildenbrand <[email protected]>" [unknown]
 # gpg: WARNING: The key's User ID is not certified with a trusted signature!
 # gpg:          There is no indication that the signature belongs to the owner.
 # Primary key fingerprint: 1BD9 CAAD 735C 4C3A 460D  FCCA 4DDE 10F7 00FF 835A

* tag 'mem-2024-12-21' of https://github.com/davidhildenbrand/qemu:
  s390x: virtio-mem support
  s390x/virtio-ccw: add support for virtio based memory devices
  s390x: remember the maximum page size
  s390x/pv: prepare for memory devices
  s390x/s390-virtio-ccw: prepare for memory devices
  s390x/s390-skeys: prepare for memory devices
  s390x/s390-stattrib-kvm: prepare for memory devices and sparse memory layouts
  s390x/s390-hypercall: introduce DIAG500 STORAGE_LIMIT
  s390x: introduce s390_get_memory_limit()
  s390x/s390-virtio-ccw: move setting the maximum guest size from sclp to machine code
  s390x: rename s390-virtio-hcall* to s390-hypercall*
  s390x/s390-virtio-hcall: prepare for more diag500 hypercalls
  s390x/s390-virtio-hcall: remove hypercall registration mechanism
  s390x/s390-virtio-ccw: don't crash on weird RAM sizes
  virtio-mem: unplug memory only during system resets, not device resets

Conflicts:
- hw/s390x/s390-stattrib-kvm.c
  sysemu/ -> system/ header rename conflict.
- hw/s390x/virtio-ccw-mem.c
  Make Property array const and removed DEFINE_PROP_END_OF_LIST() to
  conform to the latest conventions.

Signed-off-by: Stefan Hajnoczi <[email protected]>

Author: stefanhaRH

MAINTAINERS

@@ -2384,6 +2384,9 @@ F: include/hw/virtio/virtio-crypto.h
 virtio based memory device
 M: David Hildenbrand <[email protected]>
 S: Supported
+F: hw/s390x/virtio-ccw-md.c
+F: hw/s390x/virtio-ccw-md.h
+F: hw/s390x/virtio-ccw-md-stubs.c
 F: hw/virtio/virtio-md-pci.c
 F: include/hw/virtio/virtio-md-pci.h
 F: stubs/virtio-md-pci.c
@@ -2395,6 +2398,8 @@ W: https://virtio-mem.gitlab.io/
 F: hw/virtio/virtio-mem.c
 F: hw/virtio/virtio-mem-pci.h
 F: hw/virtio/virtio-mem-pci.c
+F: hw/s390x/virtio-ccw-mem.c
+F: hw/s390x/virtio-ccw-mem.h
 F: include/hw/virtio/virtio-mem.h
 
 virtio-snd

hw/s390x/Kconfig

@@ -16,3 +16,4 @@ config S390_CCW_VIRTIO
     select SCLPCONSOLE
     select VIRTIO_CCW
     select MSI_NONBROKEN
+    select VIRTIO_MEM_SUPPORTED

hw/s390x/meson.build

@@ -12,7 +12,6 @@ s390x_ss.add(files(
   's390-pci-inst.c',
   's390-skeys.c',
   's390-stattrib.c',
-  's390-virtio-hcall.c',
   'sclp.c',
   'sclpcpu.c',
   'sclpquiesce.c',
@@ -28,7 +27,10 @@ s390x_ss.add(when: 'CONFIG_KVM', if_true: files(
 s390x_ss.add(when: 'CONFIG_TCG', if_true: files(
   'tod-tcg.c',
 ))
-s390x_ss.add(when: 'CONFIG_S390_CCW_VIRTIO', if_true: files('s390-virtio-ccw.c'))
+s390x_ss.add(when: 'CONFIG_S390_CCW_VIRTIO', if_true: files(
+  's390-virtio-ccw.c',
+  's390-hypercall.c',
+))
 s390x_ss.add(when: 'CONFIG_TERMINAL3270', if_true: files('3270-ccw.c'))
 s390x_ss.add(when: 'CONFIG_VFIO', if_true: files('s390-pci-vfio.c'))
 
@@ -48,8 +50,12 @@ endif
 virtio_ss.add(when: 'CONFIG_VHOST_SCSI', if_true: files('vhost-scsi-ccw.c'))
 virtio_ss.add(when: 'CONFIG_VHOST_VSOCK', if_true: files('vhost-vsock-ccw.c'))
 virtio_ss.add(when: 'CONFIG_VHOST_USER_FS', if_true: files('vhost-user-fs-ccw.c'))
+virtio_ss.add(when: 'CONFIG_VIRTIO_MD', if_true: files('virtio-ccw-md.c'))
+virtio_ss.add(when: 'CONFIG_VIRTIO_MEM', if_true: files('virtio-ccw-mem.c'))
 s390x_ss.add_all(when: 'CONFIG_VIRTIO_CCW', if_true: virtio_ss)
 
+s390x_ss.add(when: 'CONFIG_VIRTIO_MD', if_false: files('virtio-ccw-md-stubs.c'))
+
 hw_arch += {'s390x': s390x_ss}
 
 hw_s390x_modules = {}

hw/s390x/s390-hypercall.c

@@ -0,0 +1,85 @@
+/*
+ * Support for QEMU/KVM hypercalls on s390
+ *
+ * Copyright 2012 IBM Corp.
+ * Author(s): Cornelia Huck <[email protected]>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or (at
+ * your option) any later version. See the COPYING file in the top-level
+ * directory.
+ */
+
+#include "qemu/osdep.h"
+#include "cpu.h"
+#include "hw/s390x/s390-virtio-ccw.h"
+#include "hw/s390x/s390-hypercall.h"
+#include "hw/s390x/ioinst.h"
+#include "hw/s390x/css.h"
+#include "virtio-ccw.h"
+
+static int handle_virtio_notify(uint64_t mem)
+{
+    MachineState *ms = MACHINE(qdev_get_machine());
+
+    if (mem < ms->ram_size) {
+        /* Early printk */
+        return 0;
+    }
+    return -EINVAL;
+}
+
+static int handle_virtio_ccw_notify(uint64_t subch_id, uint64_t data)
+{
+    SubchDev *sch;
+    VirtIODevice *vdev;
+    int cssid, ssid, schid, m;
+    uint16_t vq_idx = data;
+
+    if (ioinst_disassemble_sch_ident(subch_id, &m, &cssid, &ssid, &schid)) {
+        return -EINVAL;
+    }
+    sch = css_find_subch(m, cssid, ssid, schid);
+    if (!sch || !css_subch_visible(sch)) {
+        return -EINVAL;
+    }
+
+    vdev = virtio_ccw_get_vdev(sch);
+    if (vq_idx >= VIRTIO_QUEUE_MAX || !virtio_queue_get_num(vdev, vq_idx)) {
+        return -EINVAL;
+    }
+
+    if (virtio_vdev_has_feature(vdev, VIRTIO_F_NOTIFICATION_DATA)) {
+        virtio_queue_set_shadow_avail_idx(virtio_get_queue(vdev, vq_idx),
+                                          (data >> 16) & 0xFFFF);
+    }
+
+    virtio_queue_notify(vdev, vq_idx);
+    return 0;
+}
+
+static uint64_t handle_storage_limit(void)
+{
+    S390CcwMachineState *s390ms = S390_CCW_MACHINE(qdev_get_machine());
+
+    return s390_get_memory_limit(s390ms) - 1;
+}
+
+void handle_diag_500(S390CPU *cpu, uintptr_t ra)
+{
+    CPUS390XState *env = &cpu->env;
+    const uint64_t subcode = env->regs[1];
+
+    switch (subcode) {
+    case DIAG500_VIRTIO_NOTIFY:
+        env->regs[2] = handle_virtio_notify(env->regs[2]);
+        break;
+    case DIAG500_VIRTIO_CCW_NOTIFY:
+        env->regs[2] = handle_virtio_ccw_notify(env->regs[2], env->regs[3]);
+        break;
+    case DIAG500_STORAGE_LIMIT:
+        env->regs[2] = handle_storage_limit();
+        break;
+    default:
+        s390_program_interrupt(env, PGM_SPECIFICATION, ra);
+    }
+}

hw/s390x/s390-hypercall.h

@@ -0,0 +1,25 @@
+/*
+ * Support for QEMU/KVM hypercalls on s390x
+ *
+ * Copyright IBM Corp. 2012, 2017
+ * Author(s): Cornelia Huck <[email protected]>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or (at
+ * your option) any later version. See the COPYING file in the top-level
+ * directory.
+ */
+
+#ifndef HW_S390_HYPERCALL_H
+#define HW_S390_HYPERCALL_H
+
+#include "cpu.h"
+
+#define DIAG500_VIRTIO_NOTIFY           0 /* legacy, implemented as a NOP */
+#define DIAG500_VIRTIO_RESET            1 /* legacy */
+#define DIAG500_VIRTIO_SET_STATUS       2 /* legacy */
+#define DIAG500_VIRTIO_CCW_NOTIFY       3 /* KVM_S390_VIRTIO_CCW_NOTIFY */
+#define DIAG500_STORAGE_LIMIT           4
+
+void handle_diag_500(S390CPU *cpu, uintptr_t ra);
+
+#endif /* HW_S390_HYPERCALL_H */

hw/s390x/s390-skeys.c

@@ -11,7 +11,7 @@
 
 #include "qemu/osdep.h"
 #include "qemu/units.h"
-#include "hw/boards.h"
+#include "hw/s390x/s390-virtio-ccw.h"
 #include "hw/qdev-properties.h"
 #include "hw/s390x/storage-keys.h"
 #include "qapi/error.h"
@@ -251,9 +251,9 @@ static bool qemu_s390_enable_skeys(S390SKeysState *ss)
      *    g_once_init_enter() is good enough.
      */
     if (g_once_init_enter(&initialized)) {
-        MachineState *machine = MACHINE(qdev_get_machine());
+        S390CcwMachineState *s390ms = S390_CCW_MACHINE(qdev_get_machine());
 
-        skeys->key_count = machine->ram_size / TARGET_PAGE_SIZE;
+        skeys->key_count = s390_get_memory_limit(s390ms) / TARGET_PAGE_SIZE;
         skeys->keydata = g_malloc0(skeys->key_count);
         g_once_init_leave(&initialized, 1);
     }

hw/s390x/s390-stattrib-kvm.c

@@ -10,11 +10,12 @@
  */
 
 #include "qemu/osdep.h"
-#include "hw/boards.h"
+#include "hw/s390x/s390-virtio-ccw.h"
 #include "migration/qemu-file.h"
 #include "hw/s390x/storage-attributes.h"
 #include "qemu/error-report.h"
 #include "system/kvm.h"
+#include "system/memory_mapping.h"
 #include "exec/ram_addr.h"
 #include "kvm/kvm_s390x.h"
 #include "qapi/error.h"
@@ -84,8 +85,8 @@ static int kvm_s390_stattrib_set_stattr(S390StAttribState *sa,
                                         uint8_t *values)
 {
     KVMS390StAttribState *sas = KVM_S390_STATTRIB(sa);
-    MachineState *machine = MACHINE(qdev_get_machine());
-    unsigned long max = machine->ram_size / TARGET_PAGE_SIZE;
+    S390CcwMachineState *s390ms = S390_CCW_MACHINE(qdev_get_machine());
+    unsigned long max = s390_get_memory_limit(s390ms) / TARGET_PAGE_SIZE;
 
     if (start_gfn + count > max) {
         error_report("Out of memory bounds when setting storage attributes");
@@ -103,39 +104,57 @@ static int kvm_s390_stattrib_set_stattr(S390StAttribState *sa,
 static void kvm_s390_stattrib_synchronize(S390StAttribState *sa)
 {
     KVMS390StAttribState *sas = KVM_S390_STATTRIB(sa);
-    MachineState *machine = MACHINE(qdev_get_machine());
-    unsigned long max = machine->ram_size / TARGET_PAGE_SIZE;
-    /* We do not need to reach the maximum buffer size allowed */
-    unsigned long cx, len = KVM_S390_SKEYS_MAX / 2;
+    S390CcwMachineState *s390ms = S390_CCW_MACHINE(qdev_get_machine());
+    unsigned long max = s390_get_memory_limit(s390ms) / TARGET_PAGE_SIZE;
+    unsigned long start_gfn, end_gfn, pages;
+    GuestPhysBlockList guest_phys_blocks;
+    GuestPhysBlock *block;
     int r;
     struct kvm_s390_cmma_log clog = {
         .flags = 0,
         .mask = ~0ULL,
     };
 
-    if (sas->incoming_buffer) {
-        for (cx = 0; cx + len <= max; cx += len) {
-            clog.start_gfn = cx;
-            clog.count = len;
-            clog.values = (uint64_t)(sas->incoming_buffer + cx);
-            r = kvm_vm_ioctl(kvm_state, KVM_S390_SET_CMMA_BITS, &clog);
-            if (r) {
-                error_report("KVM_S390_SET_CMMA_BITS failed: %s", strerror(-r));
-                return;
-            }
-        }
-        if (cx < max) {
-            clog.start_gfn = cx;
-            clog.count = max - cx;
-            clog.values = (uint64_t)(sas->incoming_buffer + cx);
+    if (!sas->incoming_buffer) {
+        return;
+    }
+    guest_phys_blocks_init(&guest_phys_blocks);
+    guest_phys_blocks_append(&guest_phys_blocks);
+
+    QTAILQ_FOREACH(block, &guest_phys_blocks.head, next) {
+        assert(QEMU_IS_ALIGNED(block->target_start, TARGET_PAGE_SIZE));
+        assert(QEMU_IS_ALIGNED(block->target_end, TARGET_PAGE_SIZE));
+
+        start_gfn = block->target_start / TARGET_PAGE_SIZE;
+        end_gfn = block->target_end / TARGET_PAGE_SIZE;
+
+        while (start_gfn < end_gfn) {
+            /* Don't exceed the maximum buffer size. */
+            pages = MIN(end_gfn - start_gfn, KVM_S390_SKEYS_MAX / 2);
+
+            /*
+             * If we ever get guest physical memory beyond the configured
+             * memory limit, something went very wrong.
+             */
+            assert(start_gfn + pages <= max);
+
+            clog.start_gfn = start_gfn;
+            clog.count = pages;
+            clog.values = (uint64_t)(sas->incoming_buffer + start_gfn);
             r = kvm_vm_ioctl(kvm_state, KVM_S390_SET_CMMA_BITS, &clog);
             if (r) {
                 error_report("KVM_S390_SET_CMMA_BITS failed: %s", strerror(-r));
+                goto out;
             }
+
+            start_gfn += pages;
         }
-        g_free(sas->incoming_buffer);
-        sas->incoming_buffer = NULL;
     }
+
+out:
+    guest_phys_blocks_free(&guest_phys_blocks);
+    g_free(sas->incoming_buffer);
+    sas->incoming_buffer = NULL;
 }
 
 static int kvm_s390_stattrib_set_migrationmode(S390StAttribState *sa, bool val,