linux-kernel - [PATCH 1/9] KVM: iommu: fix releasing unmapped page

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Date:	Sun, 29 Jul 2012 16:12:03 +0800
From:	Xiao Guangrong <xiaoguangrong@...ux.vnet.ibm.com>
To:	Avi Kivity <avi@...hat.com>
CC:	Marcelo Tosatti <mtosatti@...hat.com>,
	LKML <linux-kernel@...r.kernel.org>, KVM <kvm@...r.kernel.org>
Subject: [PATCH 1/9] KVM: iommu: fix releasing unmapped page

There are two bugs:
- the 'error page' is forgot to be released
  [ it is unneeded after commit a2766325cf9f9, for backport, we
    still do kvm_release_pfn_clean for the error pfn ]

- guest pages are always released regardless of the unmapped page
  (e,g, caused by hwpoison)

Signed-off-by: Xiao Guangrong <xiaoguangrong@...ux.vnet.ibm.com>
---
 virt/kvm/iommu.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/virt/kvm/iommu.c b/virt/kvm/iommu.c
index c03f1fb..6a67bea 100644
--- a/virt/kvm/iommu.c
+++ b/virt/kvm/iommu.c
@@ -107,6 +107,7 @@ int kvm_iommu_map_pages(struct kvm *kvm, struct kvm_memory_slot *slot)
 		 */
 		pfn = kvm_pin_pages(slot, gfn, page_size);
 		if (is_error_pfn(pfn)) {
+			kvm_release_pfn_clean(pfn);
 			gfn += 1;
 			continue;
 		}
@@ -300,6 +301,12 @@ static void kvm_iommu_put_pages(struct kvm *kvm,

 		/* Get physical address */
 		phys = iommu_iova_to_phys(domain, gfn_to_gpa(gfn));
+
+		if (!phys) {
+			gfn++;
+			continue;
+		}
+
 		pfn  = phys >> PAGE_SHIFT;

 		/* Unmap address from IO address space */
-- 
1.7.7.6

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