Used_memslots is shared by vhost kernel and user, it is equal to
dev->mem->nregions, which is correct for vhost kernel, but not for
vhost user, the latter one uses memory regions that have file
descriptor. E.g. a VM has a vhost-user NIC and 8(vhost user memslot
upper limit) memory slots, it will be failed to hotplug a new DIMM
device since vhost_has_free_slot() finds no free slot left. It
should be successful if only part of memory slots have file
descriptor, so setting used memslots for vhost-user and
vhost-kernel respectively.
Signed-off-by: Igor Mammedov <imamm...@redhat.com>
Signed-off-by: Jay Zhou <jianjay.z...@huawei.com>
Signed-off-by: Liuzhe <liuzh...@huawei.com>
---
v10:
- fix misaligned access to structures
- refine on setting used_memslots for vhost-user to
avoid side effect
v7 ... v9:
- rebased on the master
v2 ... v6:
- delete the "used_memslots" global variable, and add it
for vhost-user and vhost-kernel separately
- refine the function, commit log
- used_memslots refactoring
hw/virtio/vhost-backend.c | 15 ++++++++++++++-
hw/virtio/vhost-user.c | 30 +++++++++++++++++++++++++++---
hw/virtio/vhost.c | 13 ++++++-------
include/hw/virtio/vhost-backend.h | 6 ++++--
4 files changed, 51 insertions(+), 13 deletions(-)
diff --git a/hw/virtio/vhost-backend.c b/hw/virtio/vhost-backend.c
index 7f09efa..59def69 100644
--- a/hw/virtio/vhost-backend.c
+++ b/hw/virtio/vhost-backend.c
@@ -15,6 +15,8 @@
#include "hw/virtio/vhost-backend.h"
#include "qemu/error-report.h"
+static unsigned int vhost_kernel_used_memslots;
+
static int vhost_kernel_call(struct vhost_dev *dev, unsigned long int request,
void *arg)
{
@@ -62,6 +64,11 @@ static int vhost_kernel_memslots_limit(struct vhost_dev *dev)
return limit;
}
+static bool vhost_kernel_has_free_memslots(struct vhost_dev *dev)
+{
+ return vhost_kernel_used_memslots < vhost_kernel_memslots_limit(dev);
+}
+
static int vhost_kernel_net_set_backend(struct vhost_dev *dev,
struct vhost_vring_file *file)
{
@@ -233,11 +240,16 @@ static void vhost_kernel_set_iotlb_callback(struct
vhost_dev *dev,
qemu_set_fd_handler((uintptr_t)dev->opaque, NULL, NULL, NULL);
}
+static void vhost_kernel_set_used_memslots(struct vhost_dev *dev)
+{
+ vhost_kernel_used_memslots = dev->mem->nregions;
+}
+
static const VhostOps kernel_ops = {
.backend_type = VHOST_BACKEND_TYPE_KERNEL,
.vhost_backend_init = vhost_kernel_init,
.vhost_backend_cleanup = vhost_kernel_cleanup,
- .vhost_backend_memslots_limit = vhost_kernel_memslots_limit,
+ .vhost_backend_has_free_memslots = vhost_kernel_has_free_memslots,
.vhost_net_set_backend = vhost_kernel_net_set_backend,
.vhost_scsi_set_endpoint = vhost_kernel_scsi_set_endpoint,
.vhost_scsi_clear_endpoint = vhost_kernel_scsi_clear_endpoint,
@@ -264,6 +276,7 @@ static const VhostOps kernel_ops = {
#endif /* CONFIG_VHOST_VSOCK */
.vhost_set_iotlb_callback = vhost_kernel_set_iotlb_callback,
.vhost_send_device_iotlb_msg = vhost_kernel_send_device_iotlb_msg,
+ .vhost_set_used_memslots = vhost_kernel_set_used_memslots,
};
int vhost_set_backend_type(struct vhost_dev *dev, VhostBackendType
backend_type)
diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index 44aea5c..b9879ca 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -170,6 +170,8 @@ static VhostUserMsg m __attribute__ ((unused));
/* The version of the protocol we support */
#define VHOST_USER_VERSION (0x1)
+static int vhost_user_used_memslots;
+
struct vhost_user {
struct vhost_dev *dev;
CharBackend *chr;
@@ -1289,9 +1291,9 @@ static int vhost_user_get_vq_index(struct vhost_dev *dev,
int idx)
return idx;
}
-static int vhost_user_memslots_limit(struct vhost_dev *dev)
+static bool vhost_user_has_free_memslots(struct vhost_dev *dev)
{
- return VHOST_MEMORY_MAX_NREGIONS;
+ return vhost_user_used_memslots < VHOST_MEMORY_MAX_NREGIONS;
}
static bool vhost_user_requires_shm_log(struct vhost_dev *dev)
@@ -1559,11 +1561,32 @@ vhost_user_crypto_close_session(struct vhost_dev *dev,
uint64_t session_id)
return 0;
}
+static void vhost_user_set_used_memslots(struct vhost_dev *dev)
+{
+ int i, fd;
+ int fd_num = 0;
+
+ for (i = 0; i < dev->mem->nregions; ++i) {
+ struct vhost_memory_region *reg = dev->mem->regions + i;
+ ram_addr_t offset;
+ MemoryRegion *mr;
+
+ assert((uintptr_t)reg->userspace_addr == reg->userspace_addr);
+ mr = memory_region_from_host((void *)(uintptr_t)reg->userspace_addr,
+ &offset);
+ fd = memory_region_get_fd(mr);
+ if (fd > 0) {
+ fd_num++;
+ }
+ }
+ vhost_user_used_memslots = fd_num;
+}
+
const VhostOps user_ops = {
.backend_type = VHOST_BACKEND_TYPE_USER,
.vhost_backend_init = vhost_user_init,
.vhost_backend_cleanup = vhost_user_cleanup,
- .vhost_backend_memslots_limit = vhost_user_memslots_limit,
+ .vhost_backend_has_free_memslots = vhost_user_has_free_memslots,
.vhost_set_log_base = vhost_user_set_log_base,
.vhost_set_mem_table = vhost_user_set_mem_table,
.vhost_set_vring_addr = vhost_user_set_vring_addr,
@@ -1589,4 +1612,5 @@ const VhostOps user_ops = {
.vhost_set_config = vhost_user_set_config,
.vhost_crypto_create_session = vhost_user_crypto_create_session,
.vhost_crypto_close_session = vhost_user_crypto_close_session,
+ .vhost_set_used_memslots = vhost_user_set_used_memslots,
};
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 250f886..5bd4081 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -44,20 +44,19 @@
static struct vhost_log *vhost_log;
static struct vhost_log *vhost_log_shm;
-static unsigned int used_memslots;
static QLIST_HEAD(, vhost_dev) vhost_devices =
QLIST_HEAD_INITIALIZER(vhost_devices);
bool vhost_has_free_slot(void)
{
- unsigned int slots_limit = ~0U;
struct vhost_dev *hdev;
QLIST_FOREACH(hdev, &vhost_devices, entry) {
- unsigned int r = hdev->vhost_ops->vhost_backend_memslots_limit(hdev);
- slots_limit = MIN(slots_limit, r);
+ if (!hdev->vhost_ops->vhost_backend_has_free_memslots(hdev)) {
+ return false;
+ }
}
- return slots_limit > used_memslots;
+ return true;
}
static void vhost_dev_sync_region(struct vhost_dev *dev,
@@ -446,7 +445,6 @@ static void vhost_commit(MemoryListener *listener)
dev->n_mem_sections * sizeof dev->mem->regions[0];
dev->mem = g_realloc(dev->mem, regions_size);
dev->mem->nregions = dev->n_mem_sections;
- used_memslots = dev->mem->nregions;
for (i = 0; i < dev->n_mem_sections; i++) {
struct vhost_memory_region *cur_vmr = dev->mem->regions + i;
struct MemoryRegionSection *mrs = dev->mem_sections + i;
@@ -458,6 +456,7 @@ static void vhost_commit(MemoryListener *listener)
mrs->offset_within_region;
cur_vmr->flags_padding = 0;
}
+ dev->vhost_ops->vhost_set_used_memslots(dev);
if (!dev->started) {
goto out;
@@ -1248,7 +1247,7 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
memory_listener_register(&hdev->memory_listener, &address_space_memory);
QLIST_INSERT_HEAD(&vhost_devices, hdev, entry);
- if (used_memslots > hdev->vhost_ops->vhost_backend_memslots_limit(hdev)) {
+ if (!hdev->vhost_ops->vhost_backend_has_free_memslots(hdev)) {
error_report("vhost backend memory slots limit is less"
" than current number of present memory slots");
r = -1;
diff --git a/include/hw/virtio/vhost-backend.h
b/include/hw/virtio/vhost-backend.h
index 5dac61f..b604521 100644
--- a/include/hw/virtio/vhost-backend.h
+++ b/include/hw/virtio/vhost-backend.h
@@ -36,7 +36,7 @@ struct vhost_iotlb_msg;
typedef int (*vhost_backend_init)(struct vhost_dev *dev, void *opaque);
typedef int (*vhost_backend_cleanup)(struct vhost_dev *dev);
-typedef int (*vhost_backend_memslots_limit)(struct vhost_dev *dev);
+typedef bool (*vhost_backend_has_free_memslots)(struct vhost_dev *dev);
typedef int (*vhost_net_set_backend_op)(struct vhost_dev *dev,
struct vhost_vring_file *file);
@@ -100,12 +100,13 @@ typedef int (*vhost_crypto_create_session_op)(struct
vhost_dev *dev,
uint64_t *session_id);
typedef int (*vhost_crypto_close_session_op)(struct vhost_dev *dev,
uint64_t session_id);
+typedef void (*vhost_set_used_memslots_op)(struct vhost_dev *dev);
typedef struct VhostOps {
VhostBackendType backend_type;
vhost_backend_init vhost_backend_init;
vhost_backend_cleanup vhost_backend_cleanup;
- vhost_backend_memslots_limit vhost_backend_memslots_limit;
+ vhost_backend_has_free_memslots vhost_backend_has_free_memslots;
vhost_net_set_backend_op vhost_net_set_backend;
vhost_net_set_mtu_op vhost_net_set_mtu;
vhost_scsi_set_endpoint_op vhost_scsi_set_endpoint;
@@ -138,6 +139,7 @@ typedef struct VhostOps {
vhost_set_config_op vhost_set_config;
vhost_crypto_create_session_op vhost_crypto_create_session;
vhost_crypto_close_session_op vhost_crypto_close_session;
+ vhost_set_used_memslots_op vhost_set_used_memslots;
} VhostOps;
extern const VhostOps user_ops;
--
1.8.3.1
