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-rw-r--r--virt/kvm/pfncache.c29
1 files changed, 21 insertions, 8 deletions
diff --git a/virt/kvm/pfncache.c b/virt/kvm/pfncache.c
index 0eeb034d0674..97eec8ee3449 100644
--- a/virt/kvm/pfncache.c
+++ b/virt/kvm/pfncache.c
@@ -48,10 +48,10 @@ bool kvm_gpc_check(struct gfn_to_pfn_cache *gpc, unsigned long len)
if (!gpc->active)
return false;
- if (offset_in_page(gpc->gpa) + len > PAGE_SIZE)
+ if (gpc->generation != slots->generation || kvm_is_error_hva(gpc->uhva))
return false;
- if (gpc->generation != slots->generation || kvm_is_error_hva(gpc->uhva))
+ if (offset_in_page(gpc->uhva) + len > PAGE_SIZE)
return false;
if (!gpc->valid)
@@ -119,7 +119,7 @@ static inline bool mmu_notifier_retry_cache(struct kvm *kvm, unsigned long mmu_s
static kvm_pfn_t hva_to_pfn_retry(struct gfn_to_pfn_cache *gpc)
{
/* Note, the new page offset may be different than the old! */
- void *old_khva = gpc->khva - offset_in_page(gpc->khva);
+ void *old_khva = (void *)PAGE_ALIGN_DOWN((uintptr_t)gpc->khva);
kvm_pfn_t new_pfn = KVM_PFN_ERR_FAULT;
void *new_khva = NULL;
unsigned long mmu_seq;
@@ -192,7 +192,7 @@ static kvm_pfn_t hva_to_pfn_retry(struct gfn_to_pfn_cache *gpc)
gpc->valid = true;
gpc->pfn = new_pfn;
- gpc->khva = new_khva + offset_in_page(gpc->gpa);
+ gpc->khva = new_khva + offset_in_page(gpc->uhva);
/*
* Put the reference to the _new_ pfn. The pfn is now tracked by the
@@ -217,6 +217,7 @@ static int __kvm_gpc_refresh(struct gfn_to_pfn_cache *gpc, gpa_t gpa,
bool unmap_old = false;
unsigned long old_uhva;
kvm_pfn_t old_pfn;
+ bool hva_change = false;
void *old_khva;
int ret;
@@ -242,10 +243,10 @@ static int __kvm_gpc_refresh(struct gfn_to_pfn_cache *gpc, gpa_t gpa,
}
old_pfn = gpc->pfn;
- old_khva = gpc->khva - offset_in_page(gpc->khva);
- old_uhva = gpc->uhva;
+ old_khva = (void *)PAGE_ALIGN_DOWN((uintptr_t)gpc->khva);
+ old_uhva = PAGE_ALIGN_DOWN(gpc->uhva);
- /* If the userspace HVA is invalid, refresh that first */
+ /* Refresh the userspace HVA if necessary */
if (gpc->gpa != gpa || gpc->generation != slots->generation ||
kvm_is_error_hva(gpc->uhva)) {
gfn_t gfn = gpa_to_gfn(gpa);
@@ -259,13 +260,25 @@ static int __kvm_gpc_refresh(struct gfn_to_pfn_cache *gpc, gpa_t gpa,
ret = -EFAULT;
goto out;
}
+
+ /*
+ * Even if the GPA and/or the memslot generation changed, the
+ * HVA may still be the same.
+ */
+ if (gpc->uhva != old_uhva)
+ hva_change = true;
+ } else {
+ gpc->uhva = old_uhva;
}
+ /* Note: the offset must be correct before calling hva_to_pfn_retry() */
+ gpc->uhva += page_offset;
+
/*
* If the userspace HVA changed or the PFN was already invalid,
* drop the lock and do the HVA to PFN lookup again.
*/
- if (!gpc->valid || old_uhva != gpc->uhva) {
+ if (!gpc->valid || hva_change) {
ret = hva_to_pfn_retry(gpc);
} else {
/*