At vfio creation time, save the value of vfio container, group, and device
descriptors in CPR state. On qemu restart, vfio_realize() finds and uses
the saved descriptors.
During reuse, device and iommu state is already configured, so operations
in vfio_realize that would modify the configuration, such as vfio ioctl's,
are skipped. The result is that vfio_realize constructs qemu data
structures that reflect the current state of the device.
Signed-off-by: Steve Sistare <steven.sist...@oracle.com>
---
include/hw/vfio/vfio-cpr.h | 6 +++++
hw/vfio/container.c | 67 +++++++++++++++++++++++++++++++++++-----------
hw/vfio/cpr-legacy.c | 42 +++++++++++++++++++++++++++++
3 files changed, 100 insertions(+), 15 deletions(-)
diff --git a/include/hw/vfio/vfio-cpr.h b/include/hw/vfio/vfio-cpr.h
index d4e0bd5..5a2e5f6 100644
--- a/include/hw/vfio/vfio-cpr.h
+++ b/include/hw/vfio/vfio-cpr.h
@@ -13,6 +13,7 @@
struct VFIOContainer;
struct VFIOContainerBase;
+struct VFIOGroup;
typedef struct VFIOContainerCPR {
Error *blocker;
@@ -30,4 +31,9 @@ bool vfio_cpr_register_container(struct VFIOContainerBase
*bcontainer,
Error **errp);
void vfio_cpr_unregister_container(struct VFIOContainerBase *bcontainer);
+int vfio_cpr_group_get_device_fd(int d, const char *name);
+
+bool vfio_cpr_container_match(struct VFIOContainer *container,
+ struct VFIOGroup *group, int fd);
+
#endif /* HW_VFIO_VFIO_CPR_H */
diff --git a/hw/vfio/container.c b/hw/vfio/container.c
index 7d2035c..798abda 100644
--- a/hw/vfio/container.c
+++ b/hw/vfio/container.c
@@ -31,6 +31,8 @@
#include "system/reset.h"
#include "trace.h"
#include "qapi/error.h"
+#include "migration/cpr.h"
+#include "migration/blocker.h"
#include "pci.h"
#include "hw/vfio/vfio-container.h"
#include "hw/vfio/vfio-cpr.h"
@@ -426,7 +428,12 @@ static VFIOContainer *vfio_create_container(int fd,
VFIOGroup *group,
return NULL;
}
- if (!vfio_set_iommu(fd, group->fd, &iommu_type, errp)) {
+ /*
+ * During CPR, just set the container type and skip the ioctls, as the
+ * container and group are already configured in the kernel.
+ */
+ if (!cpr_is_incoming() &&
+ !vfio_set_iommu(fd, group->fd, &iommu_type, errp)) {
return NULL;
}
@@ -593,6 +600,11 @@ static bool vfio_container_group_add(VFIOContainer
*container, VFIOGroup *group,
group->container = container;
QLIST_INSERT_HEAD(&container->group_list, group, container_next);
vfio_group_add_kvm_device(group);
+ /*
+ * Remember the container fd for each group, so we can attach to the same
+ * container after CPR.
+ */
+ cpr_resave_fd("vfio_container_for_group", group->groupid, container->fd);
return true;
}
@@ -602,6 +614,7 @@ static void vfio_container_group_del(VFIOContainer
*container, VFIOGroup *group)
group->container = NULL;
vfio_group_del_kvm_device(group);
vfio_ram_block_discard_disable(container, false);
+ cpr_delete_fd("vfio_container_for_group", group->groupid);
}
static bool vfio_container_connect(VFIOGroup *group, AddressSpace *as,
@@ -616,17 +629,34 @@ static bool vfio_container_connect(VFIOGroup *group,
AddressSpace *as,
bool group_was_added = false;
space = vfio_address_space_get(as);
+ fd = cpr_find_fd("vfio_container_for_group", group->groupid);
- QLIST_FOREACH(bcontainer, &space->containers, next) {
- container = container_of(bcontainer, VFIOContainer, bcontainer);
- if (!ioctl(group->fd, VFIO_GROUP_SET_CONTAINER, &container->fd)) {
- return vfio_container_group_add(container, group, errp);
+ if (!cpr_is_incoming()) {
+ QLIST_FOREACH(bcontainer, &space->containers, next) {
+ container = container_of(bcontainer, VFIOContainer, bcontainer);
+ if (!ioctl(group->fd, VFIO_GROUP_SET_CONTAINER, &container->fd)) {
+ return vfio_container_group_add(container, group, errp);
+ }
}
- }
- fd = qemu_open("/dev/vfio/vfio", O_RDWR, errp);
- if (fd < 0) {
- goto fail;
+ fd = qemu_open("/dev/vfio/vfio", O_RDWR, errp);
+ if (fd < 0) {
+ goto fail;
+ }
+ } else {
+ /*
+ * For incoming CPR, the group is already attached in the kernel.
+ * If a container with matching fd is found, then update the
+ * userland group list and return. If not, then after the loop,
+ * create the container struct and group list.
+ */
+ QLIST_FOREACH(bcontainer, &space->containers, next) {
+ container = container_of(bcontainer, VFIOContainer, bcontainer);
+
+ if (vfio_cpr_container_match(container, group, fd)) {
+ return vfio_container_group_add(container, group, errp);
+ }
+ }
}
ret = ioctl(fd, VFIO_GET_API_VERSION);
@@ -698,6 +728,7 @@ static void vfio_container_disconnect(VFIOGroup *group)
QLIST_REMOVE(group, container_next);
group->container = NULL;
+ cpr_delete_fd("vfio_container_for_group", group->groupid);
/*
* Explicitly release the listener first before unset container,
@@ -751,7 +782,7 @@ static VFIOGroup *vfio_group_get(int groupid, AddressSpace
*as, Error **errp)
group = g_malloc0(sizeof(*group));
snprintf(path, sizeof(path), "/dev/vfio/%d", groupid);
- group->fd = qemu_open(path, O_RDWR, errp);
+ group->fd = cpr_open_fd(path, O_RDWR, "vfio_group", groupid, errp);
if (group->fd < 0) {
goto free_group_exit;
}
@@ -783,6 +814,7 @@ static VFIOGroup *vfio_group_get(int groupid, AddressSpace
*as, Error **errp)
return group;
close_fd_exit:
+ cpr_delete_fd("vfio_group", groupid);
close(group->fd);
free_group_exit:
@@ -804,6 +836,7 @@ static void vfio_group_put(VFIOGroup *group)
vfio_container_disconnect(group);
QLIST_REMOVE(group, next);
trace_vfio_group_put(group->fd);
+ cpr_delete_fd("vfio_group", group->groupid);
close(group->fd);
g_free(group);
}
@@ -814,7 +847,7 @@ static bool vfio_device_get(VFIOGroup *group, const char
*name,
g_autofree struct vfio_device_info *info = NULL;
int fd;
- fd = ioctl(group->fd, VFIO_GROUP_GET_DEVICE_FD, name);
+ fd = vfio_cpr_group_get_device_fd(group->fd, name);
if (fd < 0) {
error_setg_errno(errp, errno, "error getting device from group %d",
group->groupid);
@@ -827,8 +860,7 @@ static bool vfio_device_get(VFIOGroup *group, const char
*name,
info = vfio_get_device_info(fd);
if (!info) {
error_setg_errno(errp, errno, "error getting device info");
- close(fd);
- return false;
+ goto fail;
}
/*
@@ -842,8 +874,7 @@ static bool vfio_device_get(VFIOGroup *group, const char
*name,
if (!QLIST_EMPTY(&group->device_list)) {
error_setg(errp, "Inconsistent setting of support for discarding "
"RAM (e.g., balloon) within group");
- close(fd);
- return false;
+ goto fail;
}
if (!group->ram_block_discard_allowed) {
@@ -861,6 +892,11 @@ static bool vfio_device_get(VFIOGroup *group, const char
*name,
trace_vfio_device_get(name, info->flags, info->num_regions,
info->num_irqs);
return true;
+
+fail:
+ close(fd);
+ cpr_delete_fd(name, 0);
+ return false;
}
static void vfio_device_put(VFIODevice *vbasedev)
@@ -871,6 +907,7 @@ static void vfio_device_put(VFIODevice *vbasedev)
QLIST_REMOVE(vbasedev, next);
vbasedev->group = NULL;
trace_vfio_device_put(vbasedev->fd);
+ cpr_delete_fd(vbasedev->name, 0);
close(vbasedev->fd);
}
diff --git a/hw/vfio/cpr-legacy.c b/hw/vfio/cpr-legacy.c
index 419b9fb..29be64f 100644
--- a/hw/vfio/cpr-legacy.c
+++ b/hw/vfio/cpr-legacy.c
@@ -9,6 +9,7 @@
#include "qemu/osdep.h"
#include "hw/vfio/vfio-container.h"
#include "hw/vfio/vfio-cpr.h"
+#include "hw/vfio/vfio-device.h"
#include "migration/blocker.h"
#include "migration/cpr.h"
#include "migration/migration.h"
@@ -67,3 +68,44 @@ void vfio_legacy_cpr_unregister_container(VFIOContainer
*container)
migrate_del_blocker(&container->cpr.blocker);
vmstate_unregister(NULL, &vfio_container_vmstate, container);
}
+
+int vfio_cpr_group_get_device_fd(int d, const char *name)
+{
+ const int id = 0;
+ int fd = cpr_find_fd(name, id);
+
+ if (fd < 0) {
+ fd = ioctl(d, VFIO_GROUP_GET_DEVICE_FD, name);
+ if (fd >= 0) {
+ cpr_save_fd(name, id, fd);
+ }
+ }
+ return fd;
+}
+
+static bool same_device(int fd1, int fd2)
+{
+ struct stat st1, st2;
+
+ return !fstat(fd1, &st1) && !fstat(fd2, &st2) && st1.st_dev == st2.st_dev;
+}
+
+bool vfio_cpr_container_match(VFIOContainer *container, VFIOGroup *group,
+ int fd)
+{
+ if (container->fd == fd) {
+ return true;
+ }
+ if (!same_device(container->fd, fd)) {
+ return false;
+ }
+ /*
+ * Same device, different fd. This occurs when the container fd is
+ * cpr_save'd multiple times, once for each groupid, so SCM_RIGHTS
+ * produces duplicates. De-dup it.
+ */
+ cpr_delete_fd("vfio_container_for_group", group->groupid);
+ close(fd);
+ cpr_save_fd("vfio_container_for_group", group->groupid, container->fd);
+ return true;
+}
--
1.8.3.1
