* [PATCH v2 0/2] Drivers: hv: balloon: Temporary fixes for ARM64
@ 2022-03-25 2:32 Boqun Feng
2022-03-25 2:32 ` [PATCH v2 1/2] Drivers: hv: balloon: Support status report for larger page sizes Boqun Feng
` (2 more replies)
0 siblings, 3 replies; 7+ messages in thread
From: Boqun Feng @ 2022-03-25 2:32 UTC (permalink / raw)
To: Wei Liu
Cc: Vitaly Kuznetsov, linux-hyperv, K. Y. Srinivasan, Haiyang Zhang,
Stephen Hemminger, Dexuan Cui, Michael Kelley, David Hildenbrand,
linux-kernel, Boqun Feng
v1: https://lore.kernel.org/lkml/20220223131548.2234326-1-boqun.feng@gmail.com/
Changes since v1:
* Wording changes suggested by Michael Kelley.
Since Hyper-V always uses 4k pages, hv_balloon has some difficulties
working on ARM64 with larger pages[1]. Besides the memory hot add
messages of Hyper-V doesn't have the information of NUMA node id of the
added memory range, and ARM64 currently doesn't provide the conversion
from a physical address to a node id, as a result the hv_balloon driver
couldn't handle hot add properly when there are more than one NUMA node.
Among these issues, post_status() is easy to fix, while the unballoon
issue and the hot-add issue requires more discussion. To make the
hv_balloon driver work at the best effort, this patchset fixes the
post_status() and temporarily disable the balloon and hot-add
accordingly.
Looking forwards to comments and suggestions.
Regards,
Boqun
[1]: https://lore.kernel.org/lkml/20220105165028.1343706-1-vkuznets@redhat.com/
*** BLURB HERE ***
Boqun Feng (2):
Drivers: hv: balloon: Support status report for larger page sizes
Drivers: hv: balloon: Disable balloon and hot-add accordingly
drivers/hv/hv_balloon.c | 49 ++++++++++++++++++++++++++++++++++++-----
1 file changed, 44 insertions(+), 5 deletions(-)
--
2.35.1
^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH v2 1/2] Drivers: hv: balloon: Support status report for larger page sizes
2022-03-25 2:32 [PATCH v2 0/2] Drivers: hv: balloon: Temporary fixes for ARM64 Boqun Feng
@ 2022-03-25 2:32 ` Boqun Feng
2022-08-31 19:11 ` Boqun Feng
2022-03-25 2:32 ` [PATCH v2 2/2] Drivers: hv: balloon: Disable balloon and hot-add accordingly Boqun Feng
2022-04-06 13:16 ` [PATCH v2 0/2] Drivers: hv: balloon: Temporary fixes for ARM64 Wei Liu
2 siblings, 1 reply; 7+ messages in thread
From: Boqun Feng @ 2022-03-25 2:32 UTC (permalink / raw)
To: Wei Liu
Cc: Vitaly Kuznetsov, linux-hyperv, K. Y. Srinivasan, Haiyang Zhang,
Stephen Hemminger, Dexuan Cui, Michael Kelley, David Hildenbrand,
linux-kernel, Boqun Feng
DM_STATUS_REPORT expects the numbers of pages in the unit of 4k pages
(HV_HYP_PAGE) instead of guest pages, so to make it work when guest page
sizes are larger than 4k, convert the numbers of guest pages into the
numbers of HV_HYP_PAGEs.
Note that the numbers of guest pages are still used for tracing because
tracing is internal to the guest kernel.
Reported-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
---
drivers/hv/hv_balloon.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
index f2d05bff4245..062156b88a87 100644
--- a/drivers/hv/hv_balloon.c
+++ b/drivers/hv/hv_balloon.c
@@ -17,6 +17,7 @@
#include <linux/slab.h>
#include <linux/kthread.h>
#include <linux/completion.h>
+#include <linux/count_zeros.h>
#include <linux/memory_hotplug.h>
#include <linux/memory.h>
#include <linux/notifier.h>
@@ -1130,6 +1131,7 @@ static void post_status(struct hv_dynmem_device *dm)
struct dm_status status;
unsigned long now = jiffies;
unsigned long last_post = last_post_time;
+ unsigned long num_pages_avail, num_pages_committed;
if (pressure_report_delay > 0) {
--pressure_report_delay;
@@ -1154,16 +1156,21 @@ static void post_status(struct hv_dynmem_device *dm)
* num_pages_onlined) as committed to the host, otherwise it can try
* asking us to balloon them out.
*/
- status.num_avail = si_mem_available();
- status.num_committed = vm_memory_committed() +
+ num_pages_avail = si_mem_available();
+ num_pages_committed = vm_memory_committed() +
dm->num_pages_ballooned +
(dm->num_pages_added > dm->num_pages_onlined ?
dm->num_pages_added - dm->num_pages_onlined : 0) +
compute_balloon_floor();
- trace_balloon_status(status.num_avail, status.num_committed,
+ trace_balloon_status(num_pages_avail, num_pages_committed,
vm_memory_committed(), dm->num_pages_ballooned,
dm->num_pages_added, dm->num_pages_onlined);
+
+ /* Convert numbers of pages into numbers of HV_HYP_PAGEs. */
+ status.num_avail = num_pages_avail * NR_HV_HYP_PAGES_IN_PAGE;
+ status.num_committed = num_pages_committed * NR_HV_HYP_PAGES_IN_PAGE;
+
/*
* If our transaction ID is no longer current, just don't
* send the status. This can happen if we were interrupted
--
2.35.1
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH v2 2/2] Drivers: hv: balloon: Disable balloon and hot-add accordingly
2022-03-25 2:32 [PATCH v2 0/2] Drivers: hv: balloon: Temporary fixes for ARM64 Boqun Feng
2022-03-25 2:32 ` [PATCH v2 1/2] Drivers: hv: balloon: Support status report for larger page sizes Boqun Feng
@ 2022-03-25 2:32 ` Boqun Feng
2022-04-04 17:02 ` Michael Kelley (LINUX)
2022-04-06 13:16 ` [PATCH v2 0/2] Drivers: hv: balloon: Temporary fixes for ARM64 Wei Liu
2 siblings, 1 reply; 7+ messages in thread
From: Boqun Feng @ 2022-03-25 2:32 UTC (permalink / raw)
To: Wei Liu
Cc: Vitaly Kuznetsov, linux-hyperv, K. Y. Srinivasan, Haiyang Zhang,
Stephen Hemminger, Dexuan Cui, Michael Kelley, David Hildenbrand,
linux-kernel, Boqun Feng
Currently there are known potential issues for balloon and hot-add on
ARM64:
* Unballoon requests from Hyper-V should only unballoon ranges
that are guest page size aligned, otherwise guests cannot handle
because it's impossible to partially free a page. This is a
problem when guest page size > 4096 bytes.
* Memory hot-add requests from Hyper-V should provide the NUMA
node id of the added ranges or ARM64 should have a functional
memory_add_physaddr_to_nid(), otherwise the node id is missing
for add_memory().
These issues require discussions on design and implementation. In the
meanwhile, post_status() is working and essential to guest monitoring.
Therefore instead of disabling the entire hv_balloon driver, the
ballooning (when page size > 4096 bytes) and hot-add are disabled
accordingly for now. Once the issues are fixed, they can be re-enable in
these cases.
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
---
drivers/hv/hv_balloon.c | 36 ++++++++++++++++++++++++++++++++++--
1 file changed, 34 insertions(+), 2 deletions(-)
diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
index 062156b88a87..eee7402cfc02 100644
--- a/drivers/hv/hv_balloon.c
+++ b/drivers/hv/hv_balloon.c
@@ -1660,6 +1660,38 @@ static void disable_page_reporting(void)
}
}
+static int ballooning_enabled(void)
+{
+ /*
+ * Disable ballooning if the page size is not 4k (HV_HYP_PAGE_SIZE),
+ * since currently it's unclear to us whether an unballoon request can
+ * make sure all page ranges are guest page size aligned.
+ */
+ if (PAGE_SIZE != HV_HYP_PAGE_SIZE) {
+ pr_info("Ballooning disabled because page size is not 4096 bytes\n");
+ return 0;
+ }
+
+ return 1;
+}
+
+static int hot_add_enabled(void)
+{
+ /*
+ * Disable hot add on ARM64, because we currently rely on
+ * memory_add_physaddr_to_nid() to get a node id of a hot add range,
+ * however ARM64's memory_add_physaddr_to_nid() always return 0 and
+ * DM_MEM_HOT_ADD_REQUEST doesn't have the NUMA node information for
+ * add_memory().
+ */
+ if (IS_ENABLED(CONFIG_ARM64)) {
+ pr_info("Memory hot add disabled on ARM64\n");
+ return 0;
+ }
+
+ return 1;
+}
+
static int balloon_connect_vsp(struct hv_device *dev)
{
struct dm_version_request version_req;
@@ -1731,8 +1763,8 @@ static int balloon_connect_vsp(struct hv_device *dev)
* currently still requires the bits to be set, so we have to add code
* to fail the host's hot-add and balloon up/down requests, if any.
*/
- cap_msg.caps.cap_bits.balloon = 1;
- cap_msg.caps.cap_bits.hot_add = 1;
+ cap_msg.caps.cap_bits.balloon = ballooning_enabled();
+ cap_msg.caps.cap_bits.hot_add = hot_add_enabled();
/*
* Specify our alignment requirements as it relates
--
2.35.1
^ permalink raw reply related [flat|nested] 7+ messages in thread
* RE: [PATCH v2 2/2] Drivers: hv: balloon: Disable balloon and hot-add accordingly
2022-03-25 2:32 ` [PATCH v2 2/2] Drivers: hv: balloon: Disable balloon and hot-add accordingly Boqun Feng
@ 2022-04-04 17:02 ` Michael Kelley (LINUX)
0 siblings, 0 replies; 7+ messages in thread
From: Michael Kelley (LINUX) @ 2022-04-04 17:02 UTC (permalink / raw)
To: Boqun Feng, Wei Liu
Cc: vkuznets, linux-hyperv, KY Srinivasan, Haiyang Zhang,
Stephen Hemminger, Dexuan Cui, David Hildenbrand, linux-kernel
From: Boqun Feng <boqun.feng@gmail.com> Sent: Thursday, March 24, 2022 7:32 PM
>
> Currently there are known potential issues for balloon and hot-add on
> ARM64:
>
> * Unballoon requests from Hyper-V should only unballoon ranges
> that are guest page size aligned, otherwise guests cannot handle
> because it's impossible to partially free a page. This is a
> problem when guest page size > 4096 bytes.
>
> * Memory hot-add requests from Hyper-V should provide the NUMA
> node id of the added ranges or ARM64 should have a functional
> memory_add_physaddr_to_nid(), otherwise the node id is missing
> for add_memory().
>
> These issues require discussions on design and implementation. In the
> meanwhile, post_status() is working and essential to guest monitoring.
> Therefore instead of disabling the entire hv_balloon driver, the
> ballooning (when page size > 4096 bytes) and hot-add are disabled
> accordingly for now. Once the issues are fixed, they can be re-enable in
> these cases.
>
> Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
> ---
> drivers/hv/hv_balloon.c | 36 ++++++++++++++++++++++++++++++++++--
> 1 file changed, 34 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
> index 062156b88a87..eee7402cfc02 100644
> --- a/drivers/hv/hv_balloon.c
> +++ b/drivers/hv/hv_balloon.c
> @@ -1660,6 +1660,38 @@ static void disable_page_reporting(void)
> }
> }
>
> +static int ballooning_enabled(void)
> +{
> + /*
> + * Disable ballooning if the page size is not 4k (HV_HYP_PAGE_SIZE),
> + * since currently it's unclear to us whether an unballoon request can
> + * make sure all page ranges are guest page size aligned.
> + */
> + if (PAGE_SIZE != HV_HYP_PAGE_SIZE) {
> + pr_info("Ballooning disabled because page size is not 4096 bytes\n");
> + return 0;
> + }
> +
> + return 1;
> +}
> +
> +static int hot_add_enabled(void)
> +{
> + /*
> + * Disable hot add on ARM64, because we currently rely on
> + * memory_add_physaddr_to_nid() to get a node id of a hot add range,
> + * however ARM64's memory_add_physaddr_to_nid() always return 0 and
> + * DM_MEM_HOT_ADD_REQUEST doesn't have the NUMA node information for
> + * add_memory().
> + */
> + if (IS_ENABLED(CONFIG_ARM64)) {
> + pr_info("Memory hot add disabled on ARM64\n");
> + return 0;
> + }
> +
> + return 1;
> +}
> +
> static int balloon_connect_vsp(struct hv_device *dev)
> {
> struct dm_version_request version_req;
> @@ -1731,8 +1763,8 @@ static int balloon_connect_vsp(struct hv_device *dev)
> * currently still requires the bits to be set, so we have to add code
> * to fail the host's hot-add and balloon up/down requests, if any.
> */
> - cap_msg.caps.cap_bits.balloon = 1;
> - cap_msg.caps.cap_bits.hot_add = 1;
> + cap_msg.caps.cap_bits.balloon = ballooning_enabled();
> + cap_msg.caps.cap_bits.hot_add = hot_add_enabled();
>
> /*
> * Specify our alignment requirements as it relates
> --
> 2.35.1
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2 0/2] Drivers: hv: balloon: Temporary fixes for ARM64
2022-03-25 2:32 [PATCH v2 0/2] Drivers: hv: balloon: Temporary fixes for ARM64 Boqun Feng
2022-03-25 2:32 ` [PATCH v2 1/2] Drivers: hv: balloon: Support status report for larger page sizes Boqun Feng
2022-03-25 2:32 ` [PATCH v2 2/2] Drivers: hv: balloon: Disable balloon and hot-add accordingly Boqun Feng
@ 2022-04-06 13:16 ` Wei Liu
2 siblings, 0 replies; 7+ messages in thread
From: Wei Liu @ 2022-04-06 13:16 UTC (permalink / raw)
To: Boqun Feng
Cc: Wei Liu, Vitaly Kuznetsov, linux-hyperv, K. Y. Srinivasan,
Haiyang Zhang, Stephen Hemminger, Dexuan Cui, Michael Kelley,
David Hildenbrand, linux-kernel
On Fri, Mar 25, 2022 at 10:32:10AM +0800, Boqun Feng wrote:
> v1: https://lore.kernel.org/lkml/20220223131548.2234326-1-boqun.feng@gmail.com/
> Boqun Feng (2):
> Drivers: hv: balloon: Support status report for larger page sizes
> Drivers: hv: balloon: Disable balloon and hot-add accordingly
>
Applied to hyperv-fixes. Thanks!
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2 1/2] Drivers: hv: balloon: Support status report for larger page sizes
2022-03-25 2:32 ` [PATCH v2 1/2] Drivers: hv: balloon: Support status report for larger page sizes Boqun Feng
@ 2022-08-31 19:11 ` Boqun Feng
2022-09-01 9:52 ` Greg Kroah-Hartman
0 siblings, 1 reply; 7+ messages in thread
From: Boqun Feng @ 2022-08-31 19:11 UTC (permalink / raw)
To: stable, Greg Kroah-Hartman, Sasha Levin
Cc: Vitaly Kuznetsov, linux-hyperv, K. Y. Srinivasan, Haiyang Zhang,
Stephen Hemminger, Dexuan Cui, Michael Kelley, David Hildenbrand,
linux-kernel, Wei Liu
Hi,
I think we also want this patch in the 5.15 stable. Without this patch,
hv_balloon() will report incorrect memory usage to hypervisor when
running on ARM64 with PAGE_SIZE > 4k. Only 5.15 needs this because ARM64
support of HyperV guests arrived in 5.15.
Upstream id b3d6dd09ff00fdcf4f7c0cb54700ffd5dd343502
Cc: <stable@vger.kernel.org> # 5.15.x
Thanks!
Regards,
Boqun
On Fri, Mar 25, 2022 at 10:32:11AM +0800, Boqun Feng wrote:
> DM_STATUS_REPORT expects the numbers of pages in the unit of 4k pages
> (HV_HYP_PAGE) instead of guest pages, so to make it work when guest page
> sizes are larger than 4k, convert the numbers of guest pages into the
> numbers of HV_HYP_PAGEs.
>
> Note that the numbers of guest pages are still used for tracing because
> tracing is internal to the guest kernel.
>
> Reported-by: Vitaly Kuznetsov <vkuznets@redhat.com>
> Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
> Reviewed-by: Michael Kelley <mikelley@microsoft.com>
> ---
> drivers/hv/hv_balloon.c | 13 ++++++++++---
> 1 file changed, 10 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
> index f2d05bff4245..062156b88a87 100644
> --- a/drivers/hv/hv_balloon.c
> +++ b/drivers/hv/hv_balloon.c
> @@ -17,6 +17,7 @@
> #include <linux/slab.h>
> #include <linux/kthread.h>
> #include <linux/completion.h>
> +#include <linux/count_zeros.h>
> #include <linux/memory_hotplug.h>
> #include <linux/memory.h>
> #include <linux/notifier.h>
> @@ -1130,6 +1131,7 @@ static void post_status(struct hv_dynmem_device *dm)
> struct dm_status status;
> unsigned long now = jiffies;
> unsigned long last_post = last_post_time;
> + unsigned long num_pages_avail, num_pages_committed;
>
> if (pressure_report_delay > 0) {
> --pressure_report_delay;
> @@ -1154,16 +1156,21 @@ static void post_status(struct hv_dynmem_device *dm)
> * num_pages_onlined) as committed to the host, otherwise it can try
> * asking us to balloon them out.
> */
> - status.num_avail = si_mem_available();
> - status.num_committed = vm_memory_committed() +
> + num_pages_avail = si_mem_available();
> + num_pages_committed = vm_memory_committed() +
> dm->num_pages_ballooned +
> (dm->num_pages_added > dm->num_pages_onlined ?
> dm->num_pages_added - dm->num_pages_onlined : 0) +
> compute_balloon_floor();
>
> - trace_balloon_status(status.num_avail, status.num_committed,
> + trace_balloon_status(num_pages_avail, num_pages_committed,
> vm_memory_committed(), dm->num_pages_ballooned,
> dm->num_pages_added, dm->num_pages_onlined);
> +
> + /* Convert numbers of pages into numbers of HV_HYP_PAGEs. */
> + status.num_avail = num_pages_avail * NR_HV_HYP_PAGES_IN_PAGE;
> + status.num_committed = num_pages_committed * NR_HV_HYP_PAGES_IN_PAGE;
> +
> /*
> * If our transaction ID is no longer current, just don't
> * send the status. This can happen if we were interrupted
> --
> 2.35.1
>
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2 1/2] Drivers: hv: balloon: Support status report for larger page sizes
2022-08-31 19:11 ` Boqun Feng
@ 2022-09-01 9:52 ` Greg Kroah-Hartman
0 siblings, 0 replies; 7+ messages in thread
From: Greg Kroah-Hartman @ 2022-09-01 9:52 UTC (permalink / raw)
To: Boqun Feng
Cc: stable, Sasha Levin, Vitaly Kuznetsov, linux-hyperv,
K. Y. Srinivasan, Haiyang Zhang, Stephen Hemminger, Dexuan Cui,
Michael Kelley, David Hildenbrand, linux-kernel, Wei Liu
On Wed, Aug 31, 2022 at 12:11:20PM -0700, Boqun Feng wrote:
> Hi,
>
> I think we also want this patch in the 5.15 stable. Without this patch,
> hv_balloon() will report incorrect memory usage to hypervisor when
> running on ARM64 with PAGE_SIZE > 4k. Only 5.15 needs this because ARM64
> support of HyperV guests arrived in 5.15.
>
> Upstream id b3d6dd09ff00fdcf4f7c0cb54700ffd5dd343502
>
> Cc: <stable@vger.kernel.org> # 5.15.x
Now queued up, thanks.
greg k-h
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2022-09-01 9:52 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
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2022-03-25 2:32 [PATCH v2 0/2] Drivers: hv: balloon: Temporary fixes for ARM64 Boqun Feng
2022-03-25 2:32 ` [PATCH v2 1/2] Drivers: hv: balloon: Support status report for larger page sizes Boqun Feng
2022-08-31 19:11 ` Boqun Feng
2022-09-01 9:52 ` Greg Kroah-Hartman
2022-03-25 2:32 ` [PATCH v2 2/2] Drivers: hv: balloon: Disable balloon and hot-add accordingly Boqun Feng
2022-04-04 17:02 ` Michael Kelley (LINUX)
2022-04-06 13:16 ` [PATCH v2 0/2] Drivers: hv: balloon: Temporary fixes for ARM64 Wei Liu
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