2011-03-08 21:47:23

by Daniel Kiper

[permalink] [raw]
Subject: [PATCH R4 2/7] xen/balloon: HVM mode support

HVM mode support.

Signed-off-by: Daniel Kiper <[email protected]>
---
drivers/xen/balloon.c | 8 ++++----
1 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index b4206fd..952cfe2 100644
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -227,7 +227,7 @@ static int increase_reservation(unsigned long nr_pages)
set_phys_to_machine(pfn, frame_list[i]);

/* Link back into the page tables if not highmem. */
- if (pfn < max_low_pfn) {
+ if (xen_pv_domain() && !PageHighMem(page)) {
int ret;
ret = HYPERVISOR_update_va_mapping(
(unsigned long)__va(pfn << PAGE_SHIFT),
@@ -275,7 +275,7 @@ static int decrease_reservation(unsigned long nr_pages)

scrub_page(page);

- if (!PageHighMem(page)) {
+ if (xen_pv_domain() && !PageHighMem(page)) {
ret = HYPERVISOR_update_va_mapping(
(unsigned long)__va(pfn << PAGE_SHIFT),
__pte_ma(0), 0);
@@ -390,12 +390,12 @@ static int __init balloon_init(void)
unsigned long pfn, extra_pfn_end;
struct page *page;

- if (!xen_pv_domain())
+ if (!xen_domain())
return -ENODEV;

pr_info("xen_balloon: Initialising balloon driver.\n");

- balloon_stats.current_pages = min(xen_start_info->nr_pages, max_pfn);
+ balloon_stats.current_pages = xen_pv_domain() ? min(xen_start_info->nr_pages, max_pfn) : max_pfn;
balloon_stats.target_pages = balloon_stats.current_pages;
balloon_stats.balloon_low = 0;
balloon_stats.balloon_high = 0;
--
1.5.6.5


2011-03-09 13:58:55

by Stefano Stabellini

[permalink] [raw]
Subject: Re: [PATCH R4 2/7] xen/balloon: HVM mode support

On Tue, 8 Mar 2011, Daniel Kiper wrote:
> HVM mode support.

I have already a patch in linux-next to do this, please give a look at
"xen: make the ballon driver work for hvm domains":

git://xenbits.xen.org/people/sstabellini/linux-pvhvm.git linux-next

2011-03-15 14:21:24

by Daniel Kiper

[permalink] [raw]
Subject: Re: [PATCH R4 2/7] xen/balloon: HVM mode support

On Wed, Mar 09, 2011 at 01:58:30PM +0000, Stefano Stabellini wrote:
> On Tue, 8 Mar 2011, Daniel Kiper wrote:
> > HVM mode support.
>
> I have already a patch in linux-next to do this, please give a look at
> "xen: make the ballon driver work for hvm domains":
>
> git://xenbits.xen.org/people/sstabellini/linux-pvhvm.git linux-next

OK, I will remove this patch from memory hotplug patchset, however:

@@ -232,7 +232,7 @@ static int increase_reservation(unsigned long nr_pages)
set_phys_to_machine(pfn, frame_list[i]);

/* Link back into the page tables if not highmem. */
- if (pfn < max_low_pfn) {
+ if (!xen_hvm_domain() && pfn < max_low_pfn) {

Why do not write it as:

if (xen_pv_domain() && !PageHighMem(page)) ...

For me it is simpler to read (xen_pv_domain()) and make it similar
to relevant part in decrease_reservation() (!PageHighMem(page)).

@@ -280,7 +280,7 @@ static int decrease_reservation(unsigned long nr_pages)

scrub_page(page);

- if (!PageHighMem(page)) {
+ if (!xen_hvm_domain() && !PageHighMem(page)) {

As above.

@@ -392,15 +392,19 @@ static struct notifier_block xenstore_notifier;

static int __init balloon_init(void)
{
- unsigned long pfn, extra_pfn_end;
+ unsigned long pfn, nr_pages, extra_pfn_end;
struct page *page;

- if (!xen_pv_domain())
+ if (!xen_domain())
return -ENODEV;

pr_info("xen_balloon: Initialising balloon driver.\n");

- balloon_stats.current_pages = min(xen_start_info->nr_pages, max_pfn);
+ if (xen_pv_domain())
+ nr_pages = xen_start_info->nr_pages;
+ else
+ nr_pages = max_pfn;
+ balloon_stats.current_pages = min(nr_pages, max_pfn);

It could be simplified:

balloon_stats.current_pages = xen_pv_domain() ? min(xen_start_info->nr_pages, max_pfn) : max_pfn;

Daniel