From: "Dr. David Alan Gilbert"
Add a cache BAR into which files will be directly mapped.
The size cacn be set with the cache-size= property, e.g.
-device vhost-user-fs-pci,chardev=char0,tag=myfs,cache-size=16G
Signed-off-by: Dr. David Alan Gilbert
---
hw/virtio/vhost-user-fs.c | 16
hw/virtio/virtio-pci.c | 19 +++
hw/virtio/virtio-pci.h | 1 +
include/hw/virtio/vhost-user-fs.h | 2 ++
include/standard-headers/linux/virtio_fs.h | 5 +
5 files changed, 43 insertions(+)
diff --git a/hw/virtio/vhost-user-fs.c b/hw/virtio/vhost-user-fs.c
index bc21beeac3..14ee922661 100644
--- a/hw/virtio/vhost-user-fs.c
+++ b/hw/virtio/vhost-user-fs.c
@@ -195,6 +195,21 @@ static void vuf_device_realize(DeviceState *dev, Error
**errp)
VIRTQUEUE_MAX_SIZE);
return;
}
+if (!is_power_of_2(fs->conf.cache_size) ||
+fs->conf.cache_size < sysconf(_SC_PAGESIZE)) {
+error_setg(errp, "cache-size property must be a power of 2 "
+ "no smaller than the page size");
+return;
+}
+/* We need a region with some host memory, 'ram' is the easiest */
+memory_region_init_ram_nomigrate(>cache, OBJECT(vdev),
+ "virtio-fs-cache",
+ fs->conf.cache_size, NULL);
+/* But we don't actually want anyone reading/writing the raw
+ * area with no cache data.
+ */
+mprotect(memory_region_get_ram_ptr(>cache), fs->conf.cache_size,
+ PROT_NONE);
fs->vhost_user = vhost_user_init();
if (!fs->vhost_user) {
@@ -263,6 +278,7 @@ static Property vuf_properties[] = {
DEFINE_PROP_UINT16("num-queues", VHostUserFS, conf.num_queues, 1),
DEFINE_PROP_UINT16("queue-size", VHostUserFS, conf.queue_size, 128),
DEFINE_PROP_STRING("vhostfd", VHostUserFS, conf.vhostfd),
+DEFINE_PROP_SIZE("cache-size", VHostUserFS, conf.cache_size, 1ull << 30),
DEFINE_PROP_END_OF_LIST(),
};
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index d744f93655..e819a29fb1 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -18,6 +18,7 @@
#include "qemu/osdep.h"
#include "standard-headers/linux/virtio_pci.h"
+#include "standard-headers/linux/virtio_fs.h"
#include "hw/virtio/virtio.h"
#include "hw/virtio/virtio-blk.h"
#include "hw/virtio/virtio-net.h"
@@ -2678,9 +2679,27 @@ static void vhost_user_fs_pci_realize(VirtIOPCIProxy
*vpci_dev, Error **errp)
{
VHostUserFSPCI *dev = VHOST_USER_FS_PCI(vpci_dev);
DeviceState *vdev = DEVICE(>vdev);
+uint64_t cachesize;
qdev_set_parent_bus(vdev, BUS(_dev->bus));
object_property_set_bool(OBJECT(vdev), true, "realized", errp);
+cachesize = memory_region_size(>vdev.cache);
+
+/* The bar starts with the data/DAX cache
+ * Others will be added later.
+ */
+memory_region_init(>cachebar, OBJECT(vpci_dev),
+ "vhost-fs-pci-cachebar", cachesize);
+memory_region_add_subregion(>cachebar, 0, >vdev.cache);
+virtio_pci_add_shm_cap(vpci_dev, VIRTIO_FS_PCI_CACHE_BAR, 0, cachesize,
+ VIRTIO_FS_PCI_SHMCAP_ID_CACHE);
+
+/* After 'realized' so the memory region exists */
+pci_register_bar(_dev->pci_dev, VIRTIO_FS_PCI_CACHE_BAR,
+ PCI_BASE_ADDRESS_SPACE_MEMORY |
+ PCI_BASE_ADDRESS_MEM_PREFETCH |
+ PCI_BASE_ADDRESS_MEM_TYPE_64,
+ >cachebar);
}
static void vhost_user_fs_pci_class_init(ObjectClass *klass, void *data)
diff --git a/hw/virtio/virtio-pci.h b/hw/virtio/virtio-pci.h
index a635dc564c..53b87f245c 100644
--- a/hw/virtio/virtio-pci.h
+++ b/hw/virtio/virtio-pci.h
@@ -429,6 +429,7 @@ struct VirtIOCryptoPCI {
struct VHostUserFSPCI {
VirtIOPCIProxy parent_obj;
VHostUserFS vdev;
+MemoryRegion cachebar;
};
#endif
diff --git a/include/hw/virtio/vhost-user-fs.h
b/include/hw/virtio/vhost-user-fs.h
index 29629acc54..be153e1c7a 100644
--- a/include/hw/virtio/vhost-user-fs.h
+++ b/include/hw/virtio/vhost-user-fs.h
@@ -29,6 +29,7 @@ typedef struct {
uint16_t num_queues;
uint16_t queue_size;
char *vhostfd;
+size_t cache_size;
} VHostUserFSConf;
typedef struct {
@@ -40,6 +41,7 @@ typedef struct {
VhostUserState *vhost_user;
/*< public >*/
+MemoryRegion cache;
} VHostUserFS;
#endif /* _QEMU_VHOST_USER_FS_H */
diff --git a/include/standard-headers/linux/virtio_fs.h
b/include/standard-headers/linux/virtio_fs.h
index 4f811a0b70..b5f137ca79 100644
--- a/include/standard-headers/linux/virtio_fs.h
+++ b/include/standard-headers/linux/virtio_fs.h
@@ -38,4 +38,9 @@ struct virtio_fs_config {
uint32_t num_queues;
} QEMU_PACKED;
+#define VIRTIO_FS_PCI_CACHE_BAR 2
+
+/* For the id field in virtio_pci_shm_cap */
+#define VIRTIO_FS_PCI_SHMCAP_ID_CACHE 0
+
#endif /* _LINUX_VIRTIO_FS_H */
--
2.19.2
