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* [Qemu-devel] [PATCH v3] virtio-mmio: implement modern (v2) personality (virtio-1)
@ 2019-09-17 15:11 ` Michael S. Tsirkin
  0 siblings, 0 replies; 35+ messages in thread
From: Sergio Lopez @ 2019-09-13 12:06 UTC (permalink / raw)
  To: mst; +Cc: peter.maydell, Sergio Lopez, stefanha, cohuck, qemu-devel,
	abologna

Implement the modern (v2) personality, according to the VirtIO 1.0
specification.

Support for v2 among guests is not as widespread as it'd be
desirable. While the Linux driver has had it for a while, support is
missing, at least, from Tianocore EDK II, NetBSD and FreeBSD.

For this reason, the v2 personality is disabled, keeping the legacy
behavior as default. Machine types willing to use v2, can enable it
using MachineClass's compat_props.

Signed-off-by: Sergio Lopez <slp@redhat.com>
---
Changelog:

v3:
 - Use %HWADDR_PRIx instead of %x. (Stefan Hajnoczi)
 - Return 0 if host_features_sel > 0 for legacy mode. (Cornelia Huck)
 - Mask out legacy features in non-legacy mode. (Cornelia Huck)
 - Log an error in guest attempts to write guest_features with
   guest_features_sel > 0 in legacy mode. (Cornelia Huck)

v2:
 - Switch from RFC to PATCH.
 - Avoid the modern vs. legacy dichotomy. Use legacy or non-legacy
   instead. (Andrea Bolognani, Cornelia Huck)
 - Include the register offset in the warning messages. (Stefan
   Hajnoczi)
 - Fix device endianness for the non-legacy mode. (Michael S. Tsirkin)
 - Honor the specs in VIRTIO_MMIO_QUEUE_READY. (Michael S. Tsirkin)
---
 hw/virtio/virtio-mmio.c | 342 +++++++++++++++++++++++++++++++++++++---
 1 file changed, 319 insertions(+), 23 deletions(-)

diff --git a/hw/virtio/virtio-mmio.c b/hw/virtio/virtio-mmio.c
index 97b7f35496..3578ae37be 100644
--- a/hw/virtio/virtio-mmio.c
+++ b/hw/virtio/virtio-mmio.c
@@ -47,14 +47,24 @@
         OBJECT_CHECK(VirtIOMMIOProxy, (obj), TYPE_VIRTIO_MMIO)
 
 #define VIRT_MAGIC 0x74726976 /* 'virt' */
-#define VIRT_VERSION 1
+#define VIRT_VERSION 2
+#define VIRT_VERSION_LEGACY 1
 #define VIRT_VENDOR 0x554D4551 /* 'QEMU' */
 
+typedef struct VirtIOMMIOQueue {
+    uint16_t num;
+    bool enabled;
+    uint32_t desc[2];
+    uint32_t avail[2];
+    uint32_t used[2];
+} VirtIOMMIOQueue;
+
 typedef struct {
     /* Generic */
     SysBusDevice parent_obj;
     MemoryRegion iomem;
     qemu_irq irq;
+    bool legacy;
     /* Guest accessible state needing migration and reset */
     uint32_t host_features_sel;
     uint32_t guest_features_sel;
@@ -62,6 +72,9 @@ typedef struct {
     /* virtio-bus */
     VirtioBusState bus;
     bool format_transport_address;
+    /* Fields only used for non-legacy (v2) devices */
+    uint32_t guest_features[2];
+    VirtIOMMIOQueue vqs[VIRTIO_QUEUE_MAX];
 } VirtIOMMIOProxy;
 
 static bool virtio_mmio_ioeventfd_enabled(DeviceState *d)
@@ -115,7 +128,11 @@ static uint64_t virtio_mmio_read(void *opaque, hwaddr offset, unsigned size)
         case VIRTIO_MMIO_MAGIC_VALUE:
             return VIRT_MAGIC;
         case VIRTIO_MMIO_VERSION:
-            return VIRT_VERSION;
+            if (proxy->legacy) {
+                return VIRT_VERSION_LEGACY;
+            } else {
+                return VIRT_VERSION;
+            }
         case VIRTIO_MMIO_VENDOR_ID:
             return VIRT_VENDOR;
         default:
@@ -146,28 +163,64 @@ static uint64_t virtio_mmio_read(void *opaque, hwaddr offset, unsigned size)
     case VIRTIO_MMIO_MAGIC_VALUE:
         return VIRT_MAGIC;
     case VIRTIO_MMIO_VERSION:
-        return VIRT_VERSION;
+        if (proxy->legacy) {
+            return VIRT_VERSION_LEGACY;
+        } else {
+            return VIRT_VERSION;
+        }
     case VIRTIO_MMIO_DEVICE_ID:
         return vdev->device_id;
     case VIRTIO_MMIO_VENDOR_ID:
         return VIRT_VENDOR;
     case VIRTIO_MMIO_DEVICE_FEATURES:
-        if (proxy->host_features_sel) {
-            return 0;
+        if (proxy->legacy) {
+            if (proxy->host_features_sel) {
+                return 0;
+            } else {
+                return vdev->host_features;
+            }
+        } else {
+            VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
+            return (vdev->host_features & ~vdc->legacy_features)
+                >> (32 * proxy->host_features_sel);
         }
-        return vdev->host_features;
     case VIRTIO_MMIO_QUEUE_NUM_MAX:
         if (!virtio_queue_get_num(vdev, vdev->queue_sel)) {
             return 0;
         }
         return VIRTQUEUE_MAX_SIZE;
     case VIRTIO_MMIO_QUEUE_PFN:
+        if (!proxy->legacy) {
+            qemu_log_mask(LOG_GUEST_ERROR,
+                          "%s: read from legacy register (0x%"
+                          HWADDR_PRIx ") in non-legacy mode\n",
+                          __func__, offset);
+            return 0;
+        }
         return virtio_queue_get_addr(vdev, vdev->queue_sel)
             >> proxy->guest_page_shift;
+    case VIRTIO_MMIO_QUEUE_READY:
+        if (proxy->legacy) {
+            qemu_log_mask(LOG_GUEST_ERROR,
+                          "%s: read from non-legacy register (0x%"
+                          HWADDR_PRIx ") in legacy mode\n",
+                          __func__, offset);
+            return 0;
+        }
+        return proxy->vqs[vdev->queue_sel].enabled;
     case VIRTIO_MMIO_INTERRUPT_STATUS:
         return atomic_read(&vdev->isr);
     case VIRTIO_MMIO_STATUS:
         return vdev->status;
+    case VIRTIO_MMIO_CONFIG_GENERATION:
+        if (proxy->legacy) {
+            qemu_log_mask(LOG_GUEST_ERROR,
+                          "%s: read from non-legacy register (0x%"
+                          HWADDR_PRIx ") in legacy mode\n",
+                          __func__, offset);
+            return 0;
+        }
+        return vdev->generation;
     case VIRTIO_MMIO_DEVICE_FEATURES_SEL:
     case VIRTIO_MMIO_DRIVER_FEATURES:
     case VIRTIO_MMIO_DRIVER_FEATURES_SEL:
@@ -177,12 +230,20 @@ static uint64_t virtio_mmio_read(void *opaque, hwaddr offset, unsigned size)
     case VIRTIO_MMIO_QUEUE_ALIGN:
     case VIRTIO_MMIO_QUEUE_NOTIFY:
     case VIRTIO_MMIO_INTERRUPT_ACK:
+    case VIRTIO_MMIO_QUEUE_DESC_LOW:
+    case VIRTIO_MMIO_QUEUE_DESC_HIGH:
+    case VIRTIO_MMIO_QUEUE_AVAIL_LOW:
+    case VIRTIO_MMIO_QUEUE_AVAIL_HIGH:
+    case VIRTIO_MMIO_QUEUE_USED_LOW:
+    case VIRTIO_MMIO_QUEUE_USED_HIGH:
         qemu_log_mask(LOG_GUEST_ERROR,
-                      "%s: read of write-only register\n",
-                      __func__);
+                      "%s: read of write-only register (0x%" HWADDR_PRIx ")\n",
+                      __func__, offset);
         return 0;
     default:
-        qemu_log_mask(LOG_GUEST_ERROR, "%s: bad register offset\n", __func__);
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: bad register offset (0x%" HWADDR_PRIx ")\n",
+                      __func__, offset);
         return 0;
     }
     return 0;
@@ -229,17 +290,41 @@ static void virtio_mmio_write(void *opaque, hwaddr offset, uint64_t value,
     }
     switch (offset) {
     case VIRTIO_MMIO_DEVICE_FEATURES_SEL:
-        proxy->host_features_sel = value;
+        if (value) {
+            proxy->host_features_sel = 1;
+        } else {
+            proxy->host_features_sel = 0;
+        }
         break;
     case VIRTIO_MMIO_DRIVER_FEATURES:
-        if (!proxy->guest_features_sel) {
-            virtio_set_features(vdev, value);
+        if (proxy->legacy) {
+            if (proxy->guest_features_sel) {
+                qemu_log_mask(LOG_GUEST_ERROR,
+                              "%s: attempt to write guest features with "
+                              "guest_features_sel > 0 in legacy mode\n",
+                              __func__);
+            } else {
+                virtio_set_features(vdev, value);
+            }
+        } else {
+            proxy->guest_features[proxy->guest_features_sel] = value;
         }
         break;
     case VIRTIO_MMIO_DRIVER_FEATURES_SEL:
-        proxy->guest_features_sel = value;
+        if (value) {
+            proxy->guest_features_sel = 1;
+        } else {
+            proxy->guest_features_sel = 0;
+        }
         break;
     case VIRTIO_MMIO_GUEST_PAGE_SIZE:
+        if (!proxy->legacy) {
+            qemu_log_mask(LOG_GUEST_ERROR,
+                          "%s: write to legacy register (0x%"
+                          HWADDR_PRIx ") in non-legacy mode\n",
+                          __func__, offset);
+            return;
+        }
         proxy->guest_page_shift = ctz32(value);
         if (proxy->guest_page_shift > 31) {
             proxy->guest_page_shift = 0;
@@ -253,15 +338,31 @@ static void virtio_mmio_write(void *opaque, hwaddr offset, uint64_t value,
         break;
     case VIRTIO_MMIO_QUEUE_NUM:
         trace_virtio_mmio_queue_write(value, VIRTQUEUE_MAX_SIZE);
-        virtio_queue_set_num(vdev, vdev->queue_sel, value);
-        /* Note: only call this function for legacy devices */
-        virtio_queue_update_rings(vdev, vdev->queue_sel);
+        if (proxy->legacy) {
+            virtio_queue_set_num(vdev, vdev->queue_sel, value);
+            virtio_queue_update_rings(vdev, vdev->queue_sel);
+        } else {
+            proxy->vqs[vdev->queue_sel].num = value;
+        }
         break;
     case VIRTIO_MMIO_QUEUE_ALIGN:
-        /* Note: this is only valid for legacy devices */
+        if (!proxy->legacy) {
+            qemu_log_mask(LOG_GUEST_ERROR,
+                          "%s: write to legacy register (0x%"
+                          HWADDR_PRIx ") in non-legacy mode\n",
+                          __func__, offset);
+            return;
+        }
         virtio_queue_set_align(vdev, vdev->queue_sel, value);
         break;
     case VIRTIO_MMIO_QUEUE_PFN:
+        if (!proxy->legacy) {
+            qemu_log_mask(LOG_GUEST_ERROR,
+                          "%s: write to legacy register (0x%"
+                          HWADDR_PRIx ") in non-legacy mode\n",
+                          __func__, offset);
+            return;
+        }
         if (value == 0) {
             virtio_reset(vdev);
         } else {
@@ -269,6 +370,29 @@ static void virtio_mmio_write(void *opaque, hwaddr offset, uint64_t value,
                                   value << proxy->guest_page_shift);
         }
         break;
+    case VIRTIO_MMIO_QUEUE_READY:
+        if (proxy->legacy) {
+            qemu_log_mask(LOG_GUEST_ERROR,
+                          "%s: write to non-legacy register (0x%"
+                          HWADDR_PRIx ") in legacy mode\n",
+                          __func__, offset);
+            return;
+        }
+        if (value) {
+            virtio_queue_set_num(vdev, vdev->queue_sel,
+                                 proxy->vqs[vdev->queue_sel].num);
+            virtio_queue_set_rings(vdev, vdev->queue_sel,
+                ((uint64_t)proxy->vqs[vdev->queue_sel].desc[1]) << 32 |
+                proxy->vqs[vdev->queue_sel].desc[0],
+                ((uint64_t)proxy->vqs[vdev->queue_sel].avail[1]) << 32 |
+                proxy->vqs[vdev->queue_sel].avail[0],
+                ((uint64_t)proxy->vqs[vdev->queue_sel].used[1]) << 32 |
+                proxy->vqs[vdev->queue_sel].used[0]);
+            proxy->vqs[vdev->queue_sel].enabled = 1;
+        } else {
+            proxy->vqs[vdev->queue_sel].enabled = 0;
+        }
+        break;
     case VIRTIO_MMIO_QUEUE_NOTIFY:
         if (value < VIRTIO_QUEUE_MAX) {
             virtio_queue_notify(vdev, value);
@@ -283,6 +407,12 @@ static void virtio_mmio_write(void *opaque, hwaddr offset, uint64_t value,
             virtio_mmio_stop_ioeventfd(proxy);
         }
 
+        if (!proxy->legacy && (value & VIRTIO_CONFIG_S_FEATURES_OK)) {
+            virtio_set_features(vdev,
+                                ((uint64_t)proxy->guest_features[1]) << 32 |
+                                proxy->guest_features[0]);
+        }
+
         virtio_set_status(vdev, value & 0xff);
 
         if (value & VIRTIO_CONFIG_S_DRIVER_OK) {
@@ -293,6 +423,66 @@ static void virtio_mmio_write(void *opaque, hwaddr offset, uint64_t value,
             virtio_reset(vdev);
         }
         break;
+    case VIRTIO_MMIO_QUEUE_DESC_LOW:
+        if (proxy->legacy) {
+            qemu_log_mask(LOG_GUEST_ERROR,
+                          "%s: write to non-legacy register (0x%"
+                          HWADDR_PRIx ") in legacy mode\n",
+                          __func__, offset);
+            return;
+        }
+        proxy->vqs[vdev->queue_sel].desc[0] = value;
+        break;
+    case VIRTIO_MMIO_QUEUE_DESC_HIGH:
+        if (proxy->legacy) {
+            qemu_log_mask(LOG_GUEST_ERROR,
+                          "%s: write to non-legacy register (0x%"
+                          HWADDR_PRIx ") in legacy mode\n",
+                          __func__, offset);
+            return;
+        }
+        proxy->vqs[vdev->queue_sel].desc[1] = value;
+        break;
+    case VIRTIO_MMIO_QUEUE_AVAIL_LOW:
+        if (proxy->legacy) {
+            qemu_log_mask(LOG_GUEST_ERROR,
+                          "%s: write to non-legacy register (0x%"
+                          HWADDR_PRIx ") in legacy mode\n",
+                          __func__, offset);
+            return;
+        }
+        proxy->vqs[vdev->queue_sel].avail[0] = value;
+        break;
+    case VIRTIO_MMIO_QUEUE_AVAIL_HIGH:
+        if (proxy->legacy) {
+            qemu_log_mask(LOG_GUEST_ERROR,
+                          "%s: write to non-legacy register (0x%"
+                          HWADDR_PRIx ") in legacy mode\n",
+                          __func__, offset);
+            return;
+        }
+        proxy->vqs[vdev->queue_sel].avail[1] = value;
+        break;
+    case VIRTIO_MMIO_QUEUE_USED_LOW:
+        if (proxy->legacy) {
+            qemu_log_mask(LOG_GUEST_ERROR,
+                          "%s: write to non-legacy register (0x%"
+                          HWADDR_PRIx ") in legacy mode\n",
+                          __func__, offset);
+            return;
+        }
+        proxy->vqs[vdev->queue_sel].used[0] = value;
+        break;
+    case VIRTIO_MMIO_QUEUE_USED_HIGH:
+        if (proxy->legacy) {
+            qemu_log_mask(LOG_GUEST_ERROR,
+                          "%s: write to non-legacy register (0x%"
+                          HWADDR_PRIx ") in legacy mode\n",
+                          __func__, offset);
+            return;
+        }
+        proxy->vqs[vdev->queue_sel].used[1] = value;
+        break;
     case VIRTIO_MMIO_MAGIC_VALUE:
     case VIRTIO_MMIO_VERSION:
     case VIRTIO_MMIO_DEVICE_ID:
@@ -300,22 +490,31 @@ static void virtio_mmio_write(void *opaque, hwaddr offset, uint64_t value,
     case VIRTIO_MMIO_DEVICE_FEATURES:
     case VIRTIO_MMIO_QUEUE_NUM_MAX:
     case VIRTIO_MMIO_INTERRUPT_STATUS:
+    case VIRTIO_MMIO_CONFIG_GENERATION:
         qemu_log_mask(LOG_GUEST_ERROR,
-                      "%s: write to readonly register\n",
-                      __func__);
+                      "%s: write to read-only register (0x%" HWADDR_PRIx ")\n",
+                      __func__, offset);
         break;
 
     default:
-        qemu_log_mask(LOG_GUEST_ERROR, "%s: bad register offset\n", __func__);
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: bad register offset (0x%" HWADDR_PRIx ")\n",
+                      __func__, offset);
     }
 }
 
-static const MemoryRegionOps virtio_mem_ops = {
+static const MemoryRegionOps virtio_legacy_mem_ops = {
     .read = virtio_mmio_read,
     .write = virtio_mmio_write,
     .endianness = DEVICE_NATIVE_ENDIAN,
 };
 
+static const MemoryRegionOps virtio_mem_ops = {
+    .read = virtio_mmio_read,
+    .write = virtio_mmio_write,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+};
+
 static void virtio_mmio_update_irq(DeviceState *opaque, uint16_t vector)
 {
     VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
@@ -349,15 +548,90 @@ static void virtio_mmio_save_config(DeviceState *opaque, QEMUFile *f)
     qemu_put_be32(f, proxy->guest_page_shift);
 }
 
+static const VMStateDescription vmstate_virtio_mmio_queue_state = {
+    .name = "virtio_mmio/queue_state",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT16(num, VirtIOMMIOQueue),
+        VMSTATE_BOOL(enabled, VirtIOMMIOQueue),
+        VMSTATE_UINT32_ARRAY(desc, VirtIOMMIOQueue, 2),
+        VMSTATE_UINT32_ARRAY(avail, VirtIOMMIOQueue, 2),
+        VMSTATE_UINT32_ARRAY(used, VirtIOMMIOQueue, 2),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static const VMStateDescription vmstate_virtio_mmio_state_sub = {
+    .name = "virtio_mmio/state",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT32_ARRAY(guest_features, VirtIOMMIOProxy, 2),
+        VMSTATE_STRUCT_ARRAY(vqs, VirtIOMMIOProxy, VIRTIO_QUEUE_MAX, 0,
+                             vmstate_virtio_mmio_queue_state,
+                             VirtIOMMIOQueue),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static const VMStateDescription vmstate_virtio_mmio = {
+    .name = "virtio_mmio",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .minimum_version_id_old = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_END_OF_LIST()
+    },
+    .subsections = (const VMStateDescription * []) {
+        &vmstate_virtio_mmio_state_sub,
+        NULL
+    }
+};
+
+static void virtio_mmio_save_extra_state(DeviceState *opaque, QEMUFile *f)
+{
+    VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
+
+    vmstate_save_state(f, &vmstate_virtio_mmio, proxy, NULL);
+}
+
+static int virtio_mmio_load_extra_state(DeviceState *opaque, QEMUFile *f)
+{
+    VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
+
+    return vmstate_load_state(f, &vmstate_virtio_mmio, proxy, 1);
+}
+
+static bool virtio_mmio_has_extra_state(DeviceState *opaque)
+{
+    VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
+
+    return !proxy->legacy;
+}
+
 static void virtio_mmio_reset(DeviceState *d)
 {
     VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
+    int i;
 
     virtio_mmio_stop_ioeventfd(proxy);
     virtio_bus_reset(&proxy->bus);
     proxy->host_features_sel = 0;
     proxy->guest_features_sel = 0;
     proxy->guest_page_shift = 0;
+
+    if (!proxy->legacy) {
+        proxy->guest_features[0] = proxy->guest_features[1] = 0;
+
+        for (i = 0; i < VIRTIO_QUEUE_MAX; i++) {
+            proxy->vqs[i].enabled = 0;
+            proxy->vqs[i].num = 0;
+            proxy->vqs[i].desc[0] = proxy->vqs[i].desc[1] = 0;
+            proxy->vqs[i].avail[0] = proxy->vqs[i].avail[1] = 0;
+            proxy->vqs[i].used[0] = proxy->vqs[i].used[1] = 0;
+        }
+    }
 }
 
 static int virtio_mmio_set_guest_notifier(DeviceState *d, int n, bool assign,
@@ -420,11 +694,22 @@ assign_error:
     return r;
 }
 
+static void virtio_mmio_pre_plugged(DeviceState *d, Error **errp)
+{
+    VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
+    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
+
+    if (!proxy->legacy) {
+        virtio_add_feature(&vdev->host_features, VIRTIO_F_VERSION_1);
+    }
+}
+
 /* virtio-mmio device */
 
 static Property virtio_mmio_properties[] = {
     DEFINE_PROP_BOOL("format_transport_address", VirtIOMMIOProxy,
                      format_transport_address, true),
+    DEFINE_PROP_BOOL("force-legacy", VirtIOMMIOProxy, legacy, true),
     DEFINE_PROP_END_OF_LIST(),
 };
 
@@ -436,8 +721,15 @@ static void virtio_mmio_realizefn(DeviceState *d, Error **errp)
     qbus_create_inplace(&proxy->bus, sizeof(proxy->bus), TYPE_VIRTIO_MMIO_BUS,
                         d, NULL);
     sysbus_init_irq(sbd, &proxy->irq);
-    memory_region_init_io(&proxy->iomem, OBJECT(d), &virtio_mem_ops, proxy,
-                          TYPE_VIRTIO_MMIO, 0x200);
+    if (proxy->legacy) {
+        memory_region_init_io(&proxy->iomem, OBJECT(d),
+                              &virtio_legacy_mem_ops, proxy,
+                              TYPE_VIRTIO_MMIO, 0x200);
+    } else {
+        memory_region_init_io(&proxy->iomem, OBJECT(d),
+                              &virtio_mem_ops, proxy,
+                              TYPE_VIRTIO_MMIO, 0x200);
+    }
     sysbus_init_mmio(sbd, &proxy->iomem);
 }
 
@@ -508,9 +800,13 @@ static void virtio_mmio_bus_class_init(ObjectClass *klass, void *data)
     k->notify = virtio_mmio_update_irq;
     k->save_config = virtio_mmio_save_config;
     k->load_config = virtio_mmio_load_config;
+    k->save_extra_state = virtio_mmio_save_extra_state;
+    k->load_extra_state = virtio_mmio_load_extra_state;
+    k->has_extra_state = virtio_mmio_has_extra_state;
     k->set_guest_notifiers = virtio_mmio_set_guest_notifiers;
     k->ioeventfd_enabled = virtio_mmio_ioeventfd_enabled;
     k->ioeventfd_assign = virtio_mmio_ioeventfd_assign;
+    k->pre_plugged = virtio_mmio_pre_plugged;
     k->has_variable_vring_alignment = true;
     bus_class->max_dev = 1;
     bus_class->get_dev_path = virtio_mmio_bus_get_dev_path;
-- 
2.21.0



^ permalink raw reply related	[flat|nested] 35+ messages in thread
* [Qemu-devel] [PULL 00/10] virtio, vhost, pc: features, fixes, cleanups.
@ 2019-09-17 15:10 Michael S. Tsirkin
  2019-09-19 10:13 ` Peter Maydell
  0 siblings, 1 reply; 35+ messages in thread
From: Michael S. Tsirkin @ 2019-09-17 15:10 UTC (permalink / raw)
  To: qemu-devel; +Cc: Peter Maydell

The following changes since commit 138985c1ef8b66e4e5b383354e133e05d01d0b5f:

  Merge remote-tracking branch 'remotes/amarkovic/tags/mips-queue-sep-12-2019' into staging (2019-09-13 16:04:46 +0100)

are available in the Git repository at:

  git://git.kernel.org/pub/scm/virt/kvm/mst/qemu.git tags/for_upstream

for you to fetch changes up to 44e687a4d9ab327761e221844ced7dc9c23350a5:

  virtio-mmio: implement modern (v2) personality (virtio-1) (2019-09-16 11:17:06 -0400)

----------------------------------------------------------------
virtio,vhost,pc: features, fixes, cleanups.

Virtio 1.0 support for virtio-mmio.
Misc fixes, cleanups.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

----------------------------------------------------------------
Laurent Vivier (1):
      MAINTAINERS: update virtio-rng and virtio-serial maintainer

Pankaj Gupta (1):
      virtio pmem: user document

Peter Xu (4):
      intel_iommu: Sanity check vfio-pci config on machine init done
      qdev/machine: Introduce hotplug_allowed hook
      pc/q35: Disallow vfio-pci hotplug without VT-d caching mode
      intel_iommu: Remove the caching-mode check during flag change

Raphael Norwitz (2):
      vhost-user-blk: prevent using uninitialized vqs
      backends/vhost-user.c: prevent using uninitialized vqs

Sergio Lopez (1):
      virtio-mmio: implement modern (v2) personality (virtio-1)

Wei Yang (1):
      docs/nvdimm: add example on persistent backend setup

 docs/nvdimm.txt           |  31 +++++
 include/hw/boards.h       |   9 ++
 include/hw/qdev-core.h    |   1 +
 backends/vhost-user.c     |   2 +-
 hw/block/vhost-user-blk.c |   2 +-
 hw/core/qdev.c            |  17 +++
 hw/i386/intel_iommu.c     |  41 +++++-
 hw/i386/pc.c              |  21 +++
 hw/virtio/virtio-mmio.c   | 342 ++++++++++++++++++++++++++++++++++++++++++----
 qdev-monitor.c            |   7 +
 MAINTAINERS               |   6 +-
 docs/virtio-pmem.rst      |  75 ++++++++++
 12 files changed, 521 insertions(+), 33 deletions(-)
 create mode 100644 docs/virtio-pmem.rst



^ permalink raw reply	[flat|nested] 35+ messages in thread
* [Qemu-devel] [PATCH v3 0/4] intel_iommu: Do sanity check of vfio-pci earlier
@ 2019-09-16  8:07 Peter Xu
  2019-09-17 15:10   ` [Qemu-devel] [PULL 05/10] " Michael S. Tsirkin
                   ` (3 more replies)
  0 siblings, 4 replies; 35+ messages in thread
From: Peter Xu @ 2019-09-16  8:07 UTC (permalink / raw)
  To: qemu-devel
  Cc: Daniel P. Berrangé, Eduardo Habkost, Michael S. Tsirkin,
	Jason Wang, Alex Williamson, peterx, Eric Auger, Bandan Das,
	Igor Mammedov, Paolo Bonzini, Richard Henderson

v3:
- repost with the correct tree

v2:
- rebase to master [Eric]
- add r-bs for Eric
- remove RFC tag

The VT-d code has some defects, one of them is that we cannot detect
the misuse of vIOMMU and vfio-pci early enough.

For example, logically this is not allowed:

  -device intel-iommu,caching-mode=off \
  -device vfio-pci,host=05:00.0

Because the caching mode is required to make vfio-pci devices
functional.

Previously we did this sanity check in vtd_iommu_notify_flag_changed()
as when the memory regions change their attributes.  However that's
too late in most cases!  Because the memory region layouts will only
change after IOMMU is enabled, and that's in most cases during the
guest OS boots.  So when the configuration is wrong, we will only bail
out during the guest boots rather than simply telling the user before
QEMU starts.

The same problem happens on device hotplug, say, when we have this:

  -device intel-iommu,caching-mode=off

Then we do something like:

  (HMP) device_add vfio-pci,host=05:00.0,bus=pcie.1

If at that time the vIOMMU is enabled in the guest then the QEMU
process will simply quit directly due to this hotplug event.  This is
a bit insane...

This series tries to solve above two problems by introducing two
sanity checks upon these places separately:

  - machine done
  - hotplug device

This is a bit awkward but I hope this could be better than before.
There is of course other solutions like hard-code the check into
vfio-pci but I feel it even more unpretty.  I didn't think out any
better way to do this, if there is please kindly shout out.

Please have a look to see whether this would be acceptable, thanks.

Peter Xu (4):
  intel_iommu: Sanity check vfio-pci config on machine init done
  qdev/machine: Introduce hotplug_allowed hook
  pc/q35: Disallow vfio-pci hotplug without VT-d caching mode
  intel_iommu: Remove the caching-mode check during flag change

 hw/core/qdev.c         | 17 +++++++++++++++++
 hw/i386/intel_iommu.c  | 41 +++++++++++++++++++++++++++++++++++------
 hw/i386/pc.c           | 21 +++++++++++++++++++++
 include/hw/boards.h    |  9 +++++++++
 include/hw/qdev-core.h |  1 +
 qdev-monitor.c         |  7 +++++++
 6 files changed, 90 insertions(+), 6 deletions(-)

-- 
2.21.0



^ permalink raw reply	[flat|nested] 35+ messages in thread
* [Qemu-devel] [PATCH v2] MAINTAINERS: update virtio-rng and virtio-serial maintainer
@ 2019-09-17 15:10 ` Michael S. Tsirkin
  0 siblings, 0 replies; 35+ messages in thread
From: Laurent Vivier @ 2019-09-10 14:03 UTC (permalink / raw)
  To: qemu-devel
  Cc: Laurent Vivier, Peter Maydell, Michael S . Tsirkin, Amit Shah,
	Amit Shah

As discussed with Amit, I volunteer to maintain virtio-rng and virtio-serial
previously maintained by Amit.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Acked-by: Amit Shah <amit@kernel.org>
---

Notes:
    v2: CC Michael
        add Acked-by from Amit

 MAINTAINERS | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/MAINTAINERS b/MAINTAINERS
index 50eaf005f40e..db916ade55cd 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1554,7 +1554,8 @@ F: include/hw/virtio/virtio-input.h
 F: contrib/vhost-user-input/*
 
 virtio-serial
-M: Amit Shah <amit@kernel.org>
+M: Laurent Vivier <lvivier@redhat.com>
+R: Amit Shah <amit@kernel.org>
 S: Supported
 F: hw/char/virtio-serial-bus.c
 F: hw/char/virtio-console.c
@@ -1563,7 +1564,8 @@ F: tests/virtio-console-test.c
 F: tests/virtio-serial-test.c
 
 virtio-rng
-M: Amit Shah <amit@kernel.org>
+M: Laurent Vivier <lvivier@redhat.com>
+R: Amit Shah <amit@kernel.org>
 S: Supported
 F: hw/virtio/virtio-rng.c
 F: include/hw/virtio/virtio-rng.h
-- 
2.21.0



^ permalink raw reply related	[flat|nested] 35+ messages in thread
* [Qemu-devel] [PATCH 1/2] vhost-user-blk: prevent using uninitialized vqs
@ 2019-09-17 15:10 ` Michael S. Tsirkin
  0 siblings, 0 replies; 35+ messages in thread
From: Raphael Norwitz @ 2019-08-22 18:34 UTC (permalink / raw)
  To: qemu-devel
  Cc: Kevin Wolf, Michael S. Tsirkin, Max Reitz,
	open list:Block layer core, Raphael Norwitz

Same rational as: e6cc11d64fc998c11a4dfcde8fda3fc33a74d844

Of the 3 virtqueues, seabios only sets cmd, leaving ctrl
and event without a physical address. This can cause
vhost_verify_ring_part_mapping to return ENOMEM, causing
the following logs:

qemu-system-x86_64: Unable to map available ring for ring 0
qemu-system-x86_64: Verify ring failure on region 0

This has already been fixed for vhost scsi devices and was
recently vhost-user scsi devices. This commit fixes it for
vhost-user-blk devices.

Suggested-by: Phillippe Mathieu-Daude <philmd@redhat.com>
Signed-off-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
---
 hw/block/vhost-user-blk.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c
index 0b8c5df..63da9bb 100644
--- a/hw/block/vhost-user-blk.c
+++ b/hw/block/vhost-user-blk.c
@@ -421,7 +421,7 @@ static void vhost_user_blk_device_realize(DeviceState *dev, Error **errp)
     }
 
     s->inflight = g_new0(struct vhost_inflight, 1);
-    s->vqs = g_new(struct vhost_virtqueue, s->num_queues);
+    s->vqs = g_new0(struct vhost_virtqueue, s->num_queues);
     s->watch = 0;
     s->connected = false;
 
-- 
1.9.4



^ permalink raw reply related	[flat|nested] 35+ messages in thread
* [Qemu-devel] [PATCH v3] virtio pmem: user document
@ 2019-09-17 15:11 ` Michael S. Tsirkin
  0 siblings, 0 replies; 35+ messages in thread
From: Pankaj Gupta @ 2019-08-21 12:16 UTC (permalink / raw)
  To: qemu-devel
  Cc: pagupta, david, cohuck, lcapitulino, mst, stefanha, riel, nilal

This patch documents the steps to use virtio pmem.
It also documents other useful information about
virtio pmem e.g use-case, comparison with Qemu NVDIMM
backend and current limitations.

Signed-off-by: Pankaj Gupta <pagupta@redhat.com>
---
v3->v3
 - Text format fixes - Cornerlia
v1->v2
 - Fixes on text format and 'Guest Data persistence'
   section - Cornelia

 docs/virtio-pmem.rst | 75 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 75 insertions(+)
 create mode 100644 docs/virtio-pmem.rst

diff --git a/docs/virtio-pmem.rst b/docs/virtio-pmem.rst
new file mode 100644
index 0000000000..e77881b26f
--- /dev/null
+++ b/docs/virtio-pmem.rst
@@ -0,0 +1,75 @@
+
+========================
+QEMU virtio pmem
+========================
+
+ This document explains the setup and usage of the virtio pmem device
+ which is available since QEMU v4.1.0.
+
+ The virtio pmem device is a paravirtualized persistent memory device
+ on regular (i.e non-NVDIMM) storage.
+
+Usecase
+--------
+
+  Virtio pmem allows to bypass the guest page cache and directly use
+  host page cache. This reduces guest memory footprint as the host can
+  make efficient memory reclaim decisions under memory pressure.
+
+o How does virtio-pmem compare to the nvdimm emulation supported by QEMU?
+
+  NVDIMM emulation on regular (i.e. non-NVDIMM) host storage does not
+  persist the guest writes as there are no defined semantics in the device
+  specification. The virtio pmem device provides guest write persistence
+  on non-NVDIMM host storage.
+
+virtio pmem usage
+-----------------
+
+  A virtio pmem device backed by a memory-backend-file can be created on
+  the QEMU command line as in the following example:
+
+  -object memory-backend-file,id=mem1,share,mem-path=./virtio_pmem.img,size=4G
+  -device virtio-pmem-pci,memdev=mem1,id=nv1
+
+   where:
+   - "object memory-backend-file,id=mem1,share,mem-path=<image>, size=<image size>"
+     creates a backend file with the specified size.
+
+   - "device virtio-pmem-pci,id=nvdimm1,memdev=mem1" creates a virtio pmem
+     pci device whose storage is provided by above memory backend device.
+
+  Multiple virtio pmem devices can be created if multiple pairs of "-object"
+  and "-device" are provided.
+
+Hotplug
+-------
+
+Virtio pmem devices can be hotplugged via the QEMU monitor. First, the
+memory backing has to be added via 'object_add'; afterwards, the virtio
+pmem device can be added via 'device_add'.
+
+For example, the following commands add another 4GB virtio pmem device to
+the guest:
+
+ (qemu) object_add memory-backend-file,id=mem2,share=on,mem-path=virtio_pmem2.img,size=4G
+ (qemu) device_add virtio-pmem-pci,id=virtio_pmem2,memdev=mem2
+
+Guest Data Persistence
+----------------------
+
+ Guest data persistence on non-NVDIMM requires guest userspace applications
+ to perform fsync/msync. This is different from a real nvdimm backend where
+ no additional fsync/msync is required. This is to persist guest writes in
+ host backing file which otherwise remains in host page cache and there is
+ risk of losing the data in case of power failure.
+
+ With virtio pmem device, MAP_SYNC mmap flag is not supported. This provides
+ a hint to application to perform fsync for write persistence.
+
+Limitations
+------------
+- Real nvdimm device backend is not supported.
+- virtio pmem hotunplug is not supported.
+- ACPI NVDIMM features like regions/namespaces are not supported.
+- ndctl command is not supported.
-- 
2.21.0



^ permalink raw reply related	[flat|nested] 35+ messages in thread
* [Qemu-devel] [PATCH v2] docs/nvdimm: add example on persistent backend setup
@ 2019-09-17 15:10 ` Michael S. Tsirkin
  0 siblings, 0 replies; 35+ messages in thread
From: Wei Yang @ 2019-08-01  0:40 UTC (permalink / raw)
  To: qemu-devel; +Cc: pagupta, Wei Yang, xiaoguangrong.eric, stefanha, mst

Persistent backend setup requires some knowledge about nvdimm and ndctl
tool. Some users report they may struggle to gather these knowledge and
have difficulty to setup it properly.

Here we provide two examples for persistent backend and gives the link
to ndctl. By doing so, user could try it directly and do more
investigation on persistent backend setup with ndctl.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Reviewed-by: Pankaj Gupta <pagupta@redhat.com>

---
v2: rephrase the doc based on Stefan Hajnoczi's suggestion
---
 docs/nvdimm.txt | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/docs/nvdimm.txt b/docs/nvdimm.txt
index b531cacd35..362e99109e 100644
--- a/docs/nvdimm.txt
+++ b/docs/nvdimm.txt
@@ -171,6 +171,35 @@ guest software that this vNVDIMM device contains a region that cannot
 accept persistent writes. In result, for example, the guest Linux
 NVDIMM driver, marks such vNVDIMM device as read-only.
 
+Backend File Setup Example
+--------------------------
+
+Here are two examples showing how to setup these persistent backends on
+linux using the tool ndctl [3].
+
+A. DAX device
+
+Use the following command to set up /dev/dax0.0 so that the entirety of
+namespace0.0 can be exposed as an emulated NVDIMM to the guest:
+
+    ndctl create-namespace -f -e namespace0.0 -m devdax
+
+The /dev/dax0.0 could be used directly in "mem-path" option.
+
+B. DAX file
+
+Individual files on a DAX host file system can be exposed as emulated
+NVDIMMS.  First an fsdax block device is created, partitioned, and then
+mounted with the "dax" mount option:
+
+    ndctl create-namespace -f -e namespace0.0 -m fsdax
+    (partition /dev/pmem0 with name pmem0p1)
+    mount -o dax /dev/pmem0p1 /mnt
+    (create or copy a disk image file with qemu-img(1), cp(1), or dd(1)
+     in /mnt)
+
+Then the new file in /mnt could be used in "mem-path" option.
+
 NVDIMM Persistence
 ------------------
 
@@ -212,3 +241,5 @@ References
     https://www.snia.org/sites/default/files/technical_work/final/NVMProgrammingModel_v1.2.pdf
 [2] Persistent Memory Development Kit (PMDK), formerly known as NVML project, home page:
     http://pmem.io/pmdk/
+[3] ndctl-create-namespace - provision or reconfigure a namespace
+    http://pmem.io/ndctl/ndctl-create-namespace.html
-- 
2.17.1



^ permalink raw reply related	[flat|nested] 35+ messages in thread

end of thread, other threads:[~2019-09-23 14:01 UTC | newest]

Thread overview: 35+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2019-09-13 12:06 [Qemu-devel] [PATCH v3] virtio-mmio: implement modern (v2) personality (virtio-1) Sergio Lopez
2019-09-17 15:11 ` [Qemu-devel] [PULL 10/10] " Michael S. Tsirkin
2019-09-16 14:40 ` [Qemu-devel] [PATCH v3] " Cornelia Huck
2019-09-21  7:06 ` [Qemu-devel] [PATCH v3] virtio-mmio: implement modern (v2), " Vasyl Vavrychuk
2019-09-23 13:58   ` Sergio Lopez
  -- strict thread matches above, loose matches on Subject: below --
2019-09-17 15:10 [Qemu-devel] [PULL 00/10] virtio, vhost, pc: features, fixes, cleanups Michael S. Tsirkin
2019-09-19 10:13 ` Peter Maydell
2019-09-16  8:07 [Qemu-devel] [PATCH v3 0/4] intel_iommu: Do sanity check of vfio-pci earlier Peter Xu
2019-09-16  8:07 ` [Qemu-devel] [PATCH v3 1/4] intel_iommu: Sanity check vfio-pci config on machine init done Peter Xu
2019-09-17 15:10   ` [Qemu-devel] [PULL 05/10] " Michael S. Tsirkin
2019-09-16  8:07 ` [Qemu-devel] [PATCH v3 2/4] qdev/machine: Introduce hotplug_allowed hook Peter Xu
2019-09-17 15:10   ` [Qemu-devel] [PULL 06/10] " Michael S. Tsirkin
2019-09-16  8:07 ` [Qemu-devel] [PATCH v3 3/4] pc/q35: Disallow vfio-pci hotplug without VT-d caching mode Peter Xu
2019-09-17 15:11   ` [Qemu-devel] [PULL 07/10] " Michael S. Tsirkin
2019-09-16  8:07 ` [Qemu-devel] [PATCH v3 4/4] intel_iommu: Remove the caching-mode check during flag change Peter Xu
2019-09-17 15:11   ` [Qemu-devel] [PULL 08/10] " Michael S. Tsirkin
2019-09-10 14:03 [Qemu-devel] [PATCH v2] MAINTAINERS: update virtio-rng and virtio-serial maintainer Laurent Vivier
2019-09-17 15:10 ` [Qemu-devel] [PULL 01/10] " Michael S. Tsirkin
2019-08-22 18:34 [Qemu-devel] [PATCH 1/2] vhost-user-blk: prevent using uninitialized vqs Raphael Norwitz
2019-09-17 15:10 ` [Qemu-devel] [PULL 03/10] " Michael S. Tsirkin
2019-08-22 18:34 ` [Qemu-devel] [PATCH 2/2] backends/vhost-user.c: " Raphael Norwitz
2019-09-17 15:10   ` [Qemu-devel] [PULL 04/10] " Michael S. Tsirkin
2019-08-28  8:29   ` [Qemu-devel] [PATCH 2/2] " Stefan Hajnoczi
2019-08-23  3:43 ` [Qemu-devel] [Qemu-block] [PATCH 1/2] vhost-user-blk: " yuchenlin via Qemu-devel
2019-08-28  8:28 ` [Qemu-devel] " Stefan Hajnoczi
2019-08-21 12:16 [Qemu-devel] [PATCH v3] virtio pmem: user document Pankaj Gupta
2019-09-17 15:11 ` [Qemu-devel] [PULL 09/10] " Michael S. Tsirkin
2019-08-26 12:46 ` [Qemu-devel] [PATCH v3] " Cornelia Huck
2019-09-16  6:30   ` Pankaj Gupta
2019-08-01  0:40 [Qemu-devel] [PATCH v2] docs/nvdimm: add example on persistent backend setup Wei Yang
2019-09-17 15:10 ` [Qemu-devel] [PULL 02/10] " Michael S. Tsirkin
2019-08-01  8:05 ` [Qemu-devel] [PATCH v2] " Stefan Hajnoczi
2019-09-11  8:51 ` Wei Yang
2019-09-12 12:16 ` Stefan Hajnoczi
2019-09-12 21:44   ` Wei Yang

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