2022-03-25 19:29:59

by Boqun Feng

[permalink] [raw]
Subject: [PATCH v2 1/2] Drivers: hv: balloon: Support status report for larger page sizes

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 <[email protected]>
Signed-off-by: Boqun Feng <[email protected]>
Reviewed-by: Michael Kelley <[email protected]>
---
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* If our transaction ID is no longer current, just don't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


2022-08-31 19:14:06

by Boqun Feng

[permalink] [raw]
Subject: Re: [PATCH v2 1/2] Drivers: hv: balloon: Support status report for larger page sizes

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: <[email protected]> # 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 <[email protected]>
> Signed-off-by: Boqun Feng <[email protected]>
> Reviewed-by: Michael Kelley <[email protected]>
> ---
> 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
>

2022-09-01 10:04:09

by Greg Kroah-Hartman

[permalink] [raw]
Subject: Re: [PATCH v2 1/2] Drivers: hv: balloon: Support status report for larger page sizes

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: <[email protected]> # 5.15.x

Now queued up, thanks.

greg k-h