[PATCH v2 2/7] KVM: x86: introduce memslot_set_lpage_disallowed

From: Xiao Guangrong
Date: Wed Mar 20 2013 - 04:30:55 EST


It is used to set disallowed lage page on the specified level, can be
used in later patch

Signed-off-by: Xiao Guangrong <xiaoguangrong@xxxxxxxxxxxxxxxxxx>
---
arch/x86/kvm/x86.c | 53 ++++++++++++++++++++++++++++++++++-----------------
1 files changed, 35 insertions(+), 18 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 6622ac0..e0a7f67 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6868,12 +6868,45 @@ void kvm_arch_free_memslot(struct kvm_memory_slot *free,
}
}

+static void
+memslot_set_lpage_disallowed(struct kvm_memory_slot *slot,
+ unsigned long npages, int lpage_size,
+ int lpages)
+{
+ struct kvm_lpage_info *lpage_info;
+ unsigned long ugfn;
+ int level = lpage_size + 1;
+
+ WARN_ON(!lpage_size);
+
+ lpage_info = slot->arch.lpage_info[lpage_size - 1];
+
+ if (slot->base_gfn & (KVM_PAGES_PER_HPAGE(level) - 1))
+ lpage_info[0].write_count = 1;
+
+ if ((slot->base_gfn + npages) & (KVM_PAGES_PER_HPAGE(level) - 1))
+ lpage_info[lpages - 1].write_count = 1;
+
+ ugfn = slot->userspace_addr >> PAGE_SHIFT;
+ /*
+ * If the gfn and userspace address are not aligned wrt each
+ * other, or if explicitly asked to, disable large page
+ * support for this slot
+ */
+ if ((slot->base_gfn ^ ugfn) & (KVM_PAGES_PER_HPAGE(level) - 1) ||
+ !kvm_largepages_enabled()) {
+ unsigned long j;
+
+ for (j = 0; j < lpages; ++j)
+ lpage_info[j].write_count = 1;
+ }
+}
+
int kvm_arch_create_memslot(struct kvm_memory_slot *slot, unsigned long npages)
{
int i;

for (i = 0; i < KVM_NR_PAGE_SIZES; ++i) {
- unsigned long ugfn;
int lpages;
int level = i + 1;

@@ -6892,23 +6925,7 @@ int kvm_arch_create_memslot(struct kvm_memory_slot *slot, unsigned long npages)
if (!slot->arch.lpage_info[i - 1])
goto out_free;

- if (slot->base_gfn & (KVM_PAGES_PER_HPAGE(level) - 1))
- slot->arch.lpage_info[i - 1][0].write_count = 1;
- if ((slot->base_gfn + npages) & (KVM_PAGES_PER_HPAGE(level) - 1))
- slot->arch.lpage_info[i - 1][lpages - 1].write_count = 1;
- ugfn = slot->userspace_addr >> PAGE_SHIFT;
- /*
- * If the gfn and userspace address are not aligned wrt each
- * other, or if explicitly asked to, disable large page
- * support for this slot
- */
- if ((slot->base_gfn ^ ugfn) & (KVM_PAGES_PER_HPAGE(level) - 1) ||
- !kvm_largepages_enabled()) {
- unsigned long j;
-
- for (j = 0; j < lpages; ++j)
- slot->arch.lpage_info[i - 1][j].write_count = 1;
- }
+ memslot_set_lpage_disallowed(slot, npages, i, lpages);
}

return 0;
--
1.7.7.6

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