diff options
Diffstat (limited to 'hw/vfio/common.c')
| -rw-r--r-- | hw/vfio/common.c | 53 |
1 files changed, 29 insertions, 24 deletions
diff --git a/hw/vfio/common.c b/hw/vfio/common.c index 0b3593b3c0..33357140b8 100644 --- a/hw/vfio/common.c +++ b/hw/vfio/common.c @@ -33,7 +33,6 @@ #include "qemu/error-report.h" #include "qemu/main-loop.h" #include "qemu/range.h" -#include "sysemu/balloon.h" #include "sysemu/kvm.h" #include "sysemu/reset.h" #include "trace.h" @@ -1215,31 +1214,36 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as, space = vfio_get_address_space(as); /* - * VFIO is currently incompatible with memory ballooning insofar as the + * VFIO is currently incompatible with discarding of RAM insofar as the * madvise to purge (zap) the page from QEMU's address space does not * interact with the memory API and therefore leaves stale virtual to * physical mappings in the IOMMU if the page was previously pinned. We - * therefore add a balloon inhibit for each group added to a container, + * therefore set discarding broken for each group added to a container, * whether the container is used individually or shared. This provides * us with options to allow devices within a group to opt-in and allow - * ballooning, so long as it is done consistently for a group (for instance + * discarding, so long as it is done consistently for a group (for instance * if the device is an mdev device where it is known that the host vendor * driver will never pin pages outside of the working set of the guest - * driver, which would thus not be ballooning candidates). + * driver, which would thus not be discarding candidates). * * The first opportunity to induce pinning occurs here where we attempt to * attach the group to existing containers within the AddressSpace. If any - * pages are already zapped from the virtual address space, such as from a - * previous ballooning opt-in, new pinning will cause valid mappings to be + * pages are already zapped from the virtual address space, such as from + * previous discards, new pinning will cause valid mappings to be * re-established. Likewise, when the overall MemoryListener for a new * container is registered, a replay of mappings within the AddressSpace * will occur, re-establishing any previously zapped pages as well. * - * NB. Balloon inhibiting does not currently block operation of the - * balloon driver or revoke previously pinned pages, it only prevents - * calling madvise to modify the virtual mapping of ballooned pages. + * Especially virtio-balloon is currently only prevented from discarding + * new memory, it will not yet set ram_block_discard_set_required() and + * therefore, neither stops us here or deals with the sudden memory + * consumption of inflated memory. */ - qemu_balloon_inhibit(true); + ret = ram_block_discard_disable(true); + if (ret) { + error_setg_errno(errp, -ret, "Cannot set discarding of RAM broken"); + return ret; + } QLIST_FOREACH(container, &space->containers, next) { if (!ioctl(group->fd, VFIO_GROUP_SET_CONTAINER, &container->fd)) { @@ -1405,7 +1409,7 @@ close_fd_exit: close(fd); put_space_exit: - qemu_balloon_inhibit(false); + ram_block_discard_disable(false); vfio_put_address_space(space); return ret; @@ -1526,8 +1530,8 @@ void vfio_put_group(VFIOGroup *group) return; } - if (!group->balloon_allowed) { - qemu_balloon_inhibit(false); + if (!group->ram_block_discard_allowed) { + ram_block_discard_disable(false); } vfio_kvm_device_del_group(group); vfio_disconnect_container(group); @@ -1565,22 +1569,23 @@ int vfio_get_device(VFIOGroup *group, const char *name, } /* - * Clear the balloon inhibitor for this group if the driver knows the - * device operates compatibly with ballooning. Setting must be consistent - * per group, but since compatibility is really only possible with mdev - * currently, we expect singleton groups. + * Set discarding of RAM as not broken for this group if the driver knows + * the device operates compatibly with discarding. Setting must be + * consistent per group, but since compatibility is really only possible + * with mdev currently, we expect singleton groups. */ - if (vbasedev->balloon_allowed != group->balloon_allowed) { + if (vbasedev->ram_block_discard_allowed != + group->ram_block_discard_allowed) { if (!QLIST_EMPTY(&group->device_list)) { - error_setg(errp, - "Inconsistent device balloon setting within group"); + error_setg(errp, "Inconsistent setting of support for discarding " + "RAM (e.g., balloon) within group"); close(fd); return -1; } - if (!group->balloon_allowed) { - group->balloon_allowed = true; - qemu_balloon_inhibit(false); + if (!group->ram_block_discard_allowed) { + group->ram_block_discard_allowed = true; + ram_block_discard_disable(false); } } |