From: David Hildenbrand <david@redhat.com>
To: qemu-devel@nongnu.org
Cc: Marek Kedzierski <mkedzier@redhat.com>,
Pankaj Gupta <pankaj.gupta.linux@gmail.com>,
Wei Yang <richard.weiyang@linux.alibaba.com>,
David Hildenbrand <david@redhat.com>,
"Michael S. Tsirkin" <mst@redhat.com>,
Alex Williamson <alex.williamson@redhat.com>,
Peter Xu <peterx@redhat.com>,
"Dr . David Alan Gilbert" <dgilbert@redhat.com>,
Auger Eric <eric.auger@redhat.com>,
Pankaj Gupta <pankaj.gupta@cloud.ionos.com>,
teawater <teawaterz@linux.alibaba.com>,
Jonathan Cameron <Jonathan.Cameron@huawei.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Igor Mammedov <imammedo@redhat.com>
Subject: [PATCH v4 11/11] vfio: Disable only uncoordinated discards
Date: Thu, 7 Jan 2021 14:34:23 +0100 [thread overview]
Message-ID: <20210107133423.44964-12-david@redhat.com> (raw)
In-Reply-To: <20210107133423.44964-1-david@redhat.com>
We support coordinated discarding of RAM using the RamDiscardMgr. Let's
unlock support for coordinated discards, keeping uncoordinated discards
(e.g., via virtio-balloon) disabled.
This unlocks virtio-mem + vfio. Note that vfio used via "nvme://" by the
block layer has to be implemented/unlocked separately. For now,
virtio-mem only supports x86-64 - spapr IOMMUs are not tested/affected.
Note: The block size of a virtio-mem device has to be set to sane sizes,
depending on the maximum hotplug size - to not run out of vfio mappings.
The default virtio-mem block size is usually in the range of a couple of
MBs. The maximum number of mapping is 64k, shared with other users.
Assume you want to hotplug 256GB using virtio-mem - the block size would
have to be set to at least 8 MiB (resulting in 32768 separate mappings).
Reviewed-by: Pankaj Gupta <pankaj.gupta@cloud.ionos.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Auger Eric <eric.auger@redhat.com>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: teawater <teawaterz@linux.alibaba.com>
Cc: Marek Kedzierski <mkedzier@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
hw/vfio/common.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 2b9ba3f8c9..ee7a82524a 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -1976,8 +1976,10 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as,
* 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.
+ *
+ * We do support discarding of memory coordinated via the RamDiscardMgr.
*/
- ret = ram_block_discard_disable(true);
+ ret = ram_block_uncoordinated_discard_disable(true);
if (ret) {
error_setg_errno(errp, -ret, "Cannot set discarding of RAM broken");
return ret;
@@ -2157,7 +2159,7 @@ close_fd_exit:
close(fd);
put_space_exit:
- ram_block_discard_disable(false);
+ ram_block_uncoordinated_discard_disable(false);
vfio_put_address_space(space);
return ret;
@@ -2279,7 +2281,7 @@ void vfio_put_group(VFIOGroup *group)
}
if (!group->ram_block_discard_allowed) {
- ram_block_discard_disable(false);
+ ram_block_uncoordinated_discard_disable(false);
}
vfio_kvm_device_del_group(group);
vfio_disconnect_container(group);
@@ -2333,7 +2335,7 @@ int vfio_get_device(VFIOGroup *group, const char *name,
if (!group->ram_block_discard_allowed) {
group->ram_block_discard_allowed = true;
- ram_block_discard_disable(false);
+ ram_block_uncoordinated_discard_disable(false);
}
}
--
2.29.2
next prev parent reply other threads:[~2021-01-07 13:49 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-07 13:34 [PATCH v4 00/11] virtio-mem: vfio support David Hildenbrand
2021-01-07 13:34 ` [PATCH v4 01/11] memory: Introduce RamDiscardMgr for RAM memory regions David Hildenbrand
2021-01-07 13:34 ` [PATCH v4 02/11] virtio-mem: Factor out traversing unplugged ranges David Hildenbrand
2021-01-07 13:34 ` [PATCH v4 03/11] virtio-mem: Implement RamDiscardMgr interface David Hildenbrand
2021-01-07 13:34 ` [PATCH v4 04/11] vfio: Support for RamDiscardMgr in the !vIOMMU case David Hildenbrand
2021-01-13 23:27 ` Alex Williamson
2021-01-14 15:54 ` David Hildenbrand
2021-01-14 15:57 ` David Hildenbrand
2021-01-15 10:27 ` David Hildenbrand
2021-01-07 13:34 ` [PATCH v4 05/11] vfio: Query and store the maximum number of possible DMA mappings David Hildenbrand
2021-01-13 23:30 ` Alex Williamson
2021-01-07 13:34 ` [PATCH v4 06/11] vfio: Sanity check maximum number of DMA mappings with RamDiscardMgr David Hildenbrand
2021-01-13 23:34 ` Alex Williamson
2021-01-14 15:59 ` David Hildenbrand
2021-01-07 13:34 ` [PATCH v4 07/11] vfio: Support for RamDiscardMgr in the vIOMMU case David Hildenbrand
2021-01-07 13:34 ` [PATCH v4 08/11] softmmu/physmem: Don't use atomic operations in ram_block_discard_(disable|require) David Hildenbrand
2021-01-07 13:34 ` [PATCH v4 09/11] softmmu/physmem: Extend ram_block_discard_(require|disable) by two discard types David Hildenbrand
2021-01-07 13:34 ` [PATCH v4 10/11] virtio-mem: Require only coordinated discards David Hildenbrand
2021-01-07 13:34 ` David Hildenbrand [this message]
2021-01-13 23:57 ` [PATCH v4 11/11] vfio: Disable only uncoordinated discards Alex Williamson
2021-01-14 16:19 ` David Hildenbrand
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