[PATCH v2 09/10] KVM: do not release the error page

Xiao Guangrong
2012-08-03T07:43:30Z

After commit a2766325cf9f9, the error page is replaced by the
error code, it need not be released anymore

[ The patch has been compiling tested for powerpc ]

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
---
arch/powerpc/kvm/44x_tlb.c | 1 -
arch/powerpc/kvm/book3s_pr.c | 4 +---
arch/x86/kvm/svm.c | 1 -
arch/x86/kvm/vmx.c | 5 ++---
arch/x86/kvm/x86.c | 9 +++------
include/linux/kvm_host.h | 2 +-
virt/kvm/async_pf.c | 4 ++--
virt/kvm/kvm_main.c | 5 +++--
8 files changed, 12 insertions(+), 19 deletions(-)

diff --git a/arch/powerpc/kvm/44x_tlb.c b/arch/powerpc/kvm/44x_tlb.c
index 33aa715..5dd3ab4 100644
--- a/arch/powerpc/kvm/44x_tlb.c
+++ b/arch/powerpc/kvm/44x_tlb.c
@@ -319,7 +319,6 @@ void kvmppc_mmu_map(struct kvm_vcpu *vcpu, u64 gvaddr, gpa_t gpaddr,
if (is_error_page(new_page)) {
printk(KERN_ERR "Couldn't get guest page for gfn %llx!\n",
(unsigned long long)gfn);
- kvm_release_page_clean(new_page);
return;
}
hpaddr = page_to_phys(new_page);
diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index a1baec3..05c28f5 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -242,10 +242,8 @@ static void kvmppc_patch_dcbz(struct kvm_vcpu *vcpu, struct kvmppc_pte *pte)
int i;

hpage = gfn_to_page(vcpu->kvm, pte->raddr >> PAGE_SHIFT);
- if (is_error_page(hpage)) {
- kvm_release_page_clean(hpage);
+ if (is_error_page(hpage))
return;
- }

hpage_offset = pte->raddr & ~PAGE_MASK;
hpage_offset &= ~0xFFFULL;
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 687d0c3..31be4a5 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -2105,7 +2105,6 @@ static void *nested_svm_map(struct vcpu_svm *svm, u64 gpa, struct page **_page)
return kmap(page);

error:
- kvm_release_page_clean(page);
kvm_inject_gp(&svm->vcpu, 0);

return NULL;
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 2300e53..4b6e809 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -596,10 +596,9 @@ static inline struct vmcs12 *get_vmcs12(struct kvm_vcpu *vcpu)
static struct page *nested_get_page(struct kvm_vcpu *vcpu, gpa_t addr)
{
struct page *page = gfn_to_page(vcpu->kvm, addr >> PAGE_SHIFT);
- if (is_error_page(page)) {
- kvm_release_page_clean(page);
+ if (is_error_page(page))
return NULL;
- }
+
return page;
}

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index b6379e5..3c94d80 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1635,10 +1635,9 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data)
vcpu->arch.time_page =
gfn_to_page(vcpu->kvm, data >> PAGE_SHIFT);

- if (is_error_page(vcpu->arch.time_page)) {
- kvm_release_page_clean(vcpu->arch.time_page);
+ if (is_error_page(vcpu->arch.time_page))
vcpu->arch.time_page = NULL;
- }
+
break;
}
case MSR_KVM_ASYNC_PF_EN:
@@ -3941,10 +3940,8 @@ static int emulator_cmpxchg_emulated(struct x86_emulate_ctxt *ctxt,
goto emul_write;

page = gfn_to_page(vcpu->kvm, gpa >> PAGE_SHIFT);
- if (is_error_page(page)) {
- kvm_release_page_clean(page);
+ if (is_error_page(page))
goto emul_write;
- }

kaddr = kmap_atomic(page);
kaddr += offset_in_page(gpa);
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 0aebe7a..a8989fc 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -458,7 +458,7 @@ pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn);
pfn_t gfn_to_pfn_prot(struct kvm *kvm, gfn_t gfn, bool write_fault,
bool *writable);
pfn_t gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn);
-void kvm_release_pfn_dirty(pfn_t);
+void kvm_release_pfn_dirty(pfn_t pfn);
void kvm_release_pfn_clean(pfn_t pfn);
void kvm_set_pfn_dirty(pfn_t pfn);
void kvm_set_pfn_accessed(pfn_t pfn);
diff --git a/virt/kvm/async_pf.c b/virt/kvm/async_pf.c
index 56f5533..ea475cd 100644
--- a/virt/kvm/async_pf.c
+++ b/virt/kvm/async_pf.c
@@ -111,7 +111,7 @@ void kvm_clear_async_pf_completion_queue(struct kvm_vcpu *vcpu)
list_entry(vcpu->async_pf.done.next,
typeof(*work), link);
list_del(&work->link);
- if (work->page)
+ if (!is_error_page(work->page))
kvm_release_page_clean(work->page);
kmem_cache_free(async_pf_cache, work);
}
@@ -138,7 +138,7 @@ void kvm_check_async_pf_completion(struct kvm_vcpu *vcpu)

list_del(&work->queue);
vcpu->async_pf.queued--;
- if (work->page)
+ if (!is_error_page(work->page))
kvm_release_page_clean(work->page);
kmem_cache_free(async_pf_cache, work);
}
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index bd175f7..798ba5a 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1195,8 +1195,9 @@ EXPORT_SYMBOL_GPL(gfn_to_page);

void kvm_release_page_clean(struct page *page)
{
- if (!is_error_page(page))
- kvm_release_pfn_clean(page_to_pfn(page));
+ WARN_ON(is_error_page(page));
+
+ kvm_release_pfn_clean(page_to_pfn(page));
}
EXPORT_SYMBOL_GPL(kvm_release_page_clean);

--
1.7.7.6