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vmw_balloon: fix inflation with batching

PATCH New Nadav Amit 1 participant 1 message Jul 3, 2018

Subsystems (3)
Stable branch Char and misc drivers VMware balloon driver
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Nadav Amit

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PATCH 1/1 vmw_balloon: fix inflation with batching

Embarrassingly, the recent fix introduced worse problem than it solved, causing the balloon not to inflate. The VM informed the hypervisor that the pages for lock/unlock are sitting in the wrong address, as it used the page that is used the uninitialized page variable.

Fixes b23220fe054e9 ("vmw_balloon: fixing double free when batching mode is off")
Cc [email protected]
Reviewed-by Xavier Deguillard <[email protected]>
Signed-off-by Nadav Amit <[email protected]>
---
 drivers/misc/vmw_balloon.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
drivers/misc/vmw_balloon.c +2 -2
index efd733472a35..56c6f79a5c5a 100644
@@ -467,7 +467,7 @@ static int vmballoon_send_batched_lock(struct vmballoon *b,
 		unsigned int num_pages, bool is_2m_pages, unsigned int *target)
 {
 	unsigned long status;
-	unsigned long pfn = page_to_pfn(b->page);
+	unsigned long pfn = PHYS_PFN(virt_to_phys(b->batch_page));
 
 	STATS_INC(b->stats.lock[is_2m_pages]);
 

@@ -515,7 +515,7 @@ static bool vmballoon_send_batched_unlock(struct vmballoon *b,
 		unsigned int num_pages, bool is_2m_pages, unsigned int *target)
 {
 	unsigned long status;
-	unsigned long pfn = page_to_pfn(b->page);
+	unsigned long pfn = PHYS_PFN(virt_to_phys(b->batch_page));
 
 	STATS_INC(b->stats.unlock[is_2m_pages]);
Signature · 1 line
2.17.1