Commit 647965a2 authored by K. Y. Srinivasan's avatar K. Y. Srinivasan Committed by Greg Kroah-Hartman

Drivers: hv: balloon: Permit Linux to specify hot-add alignment requirements

Some Windows hosts permit the guest to specify memory hot-add alignment
requirements (if any). Linux currently requires a 128MB alignment on memory
segments that can be hot-added. Specify this alignment requirement to the
host.
Signed-off-by: default avatarK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 39d79164
......@@ -117,7 +117,14 @@ union dm_caps {
struct {
__u64 balloon:1;
__u64 hot_add:1;
__u64 reservedz:62;
/*
* To support guests that may have alignment
* limitations on hot-add, the guest can specify
* its alignment requirements; a value of n
* represents an alignment of 2^n in mega bytes.
*/
__u64 hot_add_alignment:4;
__u64 reservedz:58;
} cap_bits;
__u64 caps;
} __packed;
......@@ -774,7 +781,7 @@ static unsigned long process_hot_add(unsigned long pg_start,
* If the host has specified a hot-add range; deal with it first.
*/
if ((rg_size != 0) && (!dm_device.host_specified_ha_region)) {
if (rg_size != 0) {
ha_region = kzalloc(sizeof(struct hv_hotadd_state), GFP_KERNEL);
if (!ha_region)
return 0;
......@@ -1366,6 +1373,12 @@ static int balloon_probe(struct hv_device *dev,
cap_msg.caps.cap_bits.balloon = 1;
cap_msg.caps.cap_bits.hot_add = 1;
/*
* Specify our alignment requirements as it relates
* memory hot-add. Specify 128MB alignment.
*/
cap_msg.caps.cap_bits.hot_add_alignment = 7;
/*
* Currently the host does not use these
* values and we set them to what is done in the
......
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