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authorPaolo Bonzini <pbonzini@redhat.com>2022-12-02 22:00:53 +0300
committerPaolo Bonzini <pbonzini@redhat.com>2022-12-02 22:01:43 +0300
commit5656374b168c98377b6feee8d7500993eebda230 (patch)
treeb7511b4b25fa38aa77fae2342420d85e3e05cd4a /virt
parent74bee0cad8dcd8ddec5e763c369239fc5990676a (diff)
parent06e155c44aa0e7921aa44d3c67f8ea464b16cb75 (diff)
downloadlinux-5656374b168c98377b6feee8d7500993eebda230.tar.xz
Merge branch 'gpc-fixes' of git://git.infradead.org/users/dwmw2/linux into HEAD
Pull Xen-for-KVM changes from David Woodhouse: * add support for 32-bit guests in SCHEDOP_poll * the rest of the gfn-to-pfn cache API cleanup "I still haven't reinstated the last of those patches to make gpc->len immutable." Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'virt')
-rw-r--r--virt/kvm/pfncache.c104
1 files changed, 50 insertions, 54 deletions
diff --git a/virt/kvm/pfncache.c b/virt/kvm/pfncache.c
index b4295474519f..2d6aba677830 100644
--- a/virt/kvm/pfncache.c
+++ b/virt/kvm/pfncache.c
@@ -76,19 +76,17 @@ void gfn_to_pfn_cache_invalidate_start(struct kvm *kvm, unsigned long start,
}
}
-bool kvm_gpc_check(struct kvm *kvm, struct gfn_to_pfn_cache *gpc, gpa_t gpa,
- unsigned long len)
+bool kvm_gpc_check(struct gfn_to_pfn_cache *gpc, unsigned long len)
{
- struct kvm_memslots *slots = kvm_memslots(kvm);
+ struct kvm_memslots *slots = kvm_memslots(gpc->kvm);
if (!gpc->active)
return false;
- if ((gpa & ~PAGE_MASK) + len > PAGE_SIZE)
+ if ((gpc->gpa & ~PAGE_MASK) + len > PAGE_SIZE)
return false;
- if (gpc->gpa != gpa || gpc->generation != slots->generation ||
- kvm_is_error_hva(gpc->uhva))
+ if (gpc->generation != slots->generation || kvm_is_error_hva(gpc->uhva))
return false;
if (!gpc->valid)
@@ -139,7 +137,7 @@ static inline bool mmu_notifier_retry_cache(struct kvm *kvm, unsigned long mmu_s
return kvm->mmu_invalidate_seq != mmu_seq;
}
-static kvm_pfn_t hva_to_pfn_retry(struct kvm *kvm, struct gfn_to_pfn_cache *gpc)
+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);
@@ -159,7 +157,7 @@ static kvm_pfn_t hva_to_pfn_retry(struct kvm *kvm, struct gfn_to_pfn_cache *gpc)
gpc->valid = false;
do {
- mmu_seq = kvm->mmu_invalidate_seq;
+ mmu_seq = gpc->kvm->mmu_invalidate_seq;
smp_rmb();
write_unlock_irq(&gpc->lock);
@@ -217,7 +215,7 @@ static kvm_pfn_t hva_to_pfn_retry(struct kvm *kvm, struct gfn_to_pfn_cache *gpc)
* attempting to refresh.
*/
WARN_ON_ONCE(gpc->valid);
- } while (mmu_notifier_retry_cache(kvm, mmu_seq));
+ } while (mmu_notifier_retry_cache(gpc->kvm, mmu_seq));
gpc->valid = true;
gpc->pfn = new_pfn;
@@ -238,10 +236,10 @@ out_error:
return -EFAULT;
}
-int kvm_gpc_refresh(struct kvm *kvm, struct gfn_to_pfn_cache *gpc, gpa_t gpa,
- unsigned long len)
+static int __kvm_gpc_refresh(struct gfn_to_pfn_cache *gpc, gpa_t gpa,
+ unsigned long len)
{
- struct kvm_memslots *slots = kvm_memslots(kvm);
+ struct kvm_memslots *slots = kvm_memslots(gpc->kvm);
unsigned long page_offset = gpa & ~PAGE_MASK;
bool unmap_old = false;
unsigned long old_uhva;
@@ -295,7 +293,7 @@ int kvm_gpc_refresh(struct kvm *kvm, struct gfn_to_pfn_cache *gpc, gpa_t gpa,
* drop the lock and do the HVA to PFN lookup again.
*/
if (!gpc->valid || old_uhva != gpc->uhva) {
- ret = hva_to_pfn_retry(kvm, gpc);
+ ret = hva_to_pfn_retry(gpc);
} else {
/*
* If the HVA→PFN mapping was already valid, don't unmap it.
@@ -303,9 +301,8 @@ int kvm_gpc_refresh(struct kvm *kvm, struct gfn_to_pfn_cache *gpc, gpa_t gpa,
* may have changed.
*/
gpc->khva = old_khva + page_offset;
- old_pfn = KVM_PFN_ERR_FAULT;
- old_khva = NULL;
ret = 0;
+ goto out_unlock;
}
out:
@@ -333,55 +330,37 @@ out_unlock:
return ret;
}
-EXPORT_SYMBOL_GPL(kvm_gpc_refresh);
-void kvm_gpc_unmap(struct kvm *kvm, struct gfn_to_pfn_cache *gpc)
+int kvm_gpc_refresh(struct gfn_to_pfn_cache *gpc, unsigned long len)
{
- void *old_khva;
- kvm_pfn_t old_pfn;
-
- mutex_lock(&gpc->refresh_lock);
- write_lock_irq(&gpc->lock);
-
- gpc->valid = false;
-
- old_khva = gpc->khva - offset_in_page(gpc->khva);
- old_pfn = gpc->pfn;
-
- /*
- * We can leave the GPA → uHVA map cache intact but the PFN
- * lookup will need to be redone even for the same page.
- */
- gpc->khva = NULL;
- gpc->pfn = KVM_PFN_ERR_FAULT;
-
- write_unlock_irq(&gpc->lock);
- mutex_unlock(&gpc->refresh_lock);
-
- gpc_unmap_khva(old_pfn, old_khva);
+ return __kvm_gpc_refresh(gpc, gpc->gpa, len);
}
-EXPORT_SYMBOL_GPL(kvm_gpc_unmap);
+EXPORT_SYMBOL_GPL(kvm_gpc_refresh);
-void kvm_gpc_init(struct gfn_to_pfn_cache *gpc)
+void kvm_gpc_init(struct gfn_to_pfn_cache *gpc, struct kvm *kvm,
+ struct kvm_vcpu *vcpu, enum pfn_cache_usage usage)
{
+ WARN_ON_ONCE(!usage || (usage & KVM_GUEST_AND_HOST_USE_PFN) != usage);
+ WARN_ON_ONCE((usage & KVM_GUEST_USES_PFN) && !vcpu);
+
rwlock_init(&gpc->lock);
mutex_init(&gpc->refresh_lock);
+
+ gpc->kvm = kvm;
+ gpc->vcpu = vcpu;
+ gpc->usage = usage;
+ gpc->pfn = KVM_PFN_ERR_FAULT;
+ gpc->uhva = KVM_HVA_ERR_BAD;
}
EXPORT_SYMBOL_GPL(kvm_gpc_init);
-int kvm_gpc_activate(struct kvm *kvm, struct gfn_to_pfn_cache *gpc,
- struct kvm_vcpu *vcpu, enum pfn_cache_usage usage,
- gpa_t gpa, unsigned long len)
+int kvm_gpc_activate(struct gfn_to_pfn_cache *gpc, gpa_t gpa, unsigned long len)
{
- WARN_ON_ONCE(!usage || (usage & KVM_GUEST_AND_HOST_USE_PFN) != usage);
+ struct kvm *kvm = gpc->kvm;
if (!gpc->active) {
- gpc->khva = NULL;
- gpc->pfn = KVM_PFN_ERR_FAULT;
- gpc->uhva = KVM_HVA_ERR_BAD;
- gpc->vcpu = vcpu;
- gpc->usage = usage;
- gpc->valid = false;
+ if (KVM_BUG_ON(gpc->valid, kvm))
+ return -EIO;
spin_lock(&kvm->gpc_lock);
list_add(&gpc->list, &kvm->gpc_list);
@@ -396,12 +375,16 @@ int kvm_gpc_activate(struct kvm *kvm, struct gfn_to_pfn_cache *gpc,
gpc->active = true;
write_unlock_irq(&gpc->lock);
}
- return kvm_gpc_refresh(kvm, gpc, gpa, len);
+ return __kvm_gpc_refresh(gpc, gpa, len);
}
EXPORT_SYMBOL_GPL(kvm_gpc_activate);
-void kvm_gpc_deactivate(struct kvm *kvm, struct gfn_to_pfn_cache *gpc)
+void kvm_gpc_deactivate(struct gfn_to_pfn_cache *gpc)
{
+ struct kvm *kvm = gpc->kvm;
+ kvm_pfn_t old_pfn;
+ void *old_khva;
+
if (gpc->active) {
/*
* Deactivate the cache before removing it from the list, KVM
@@ -410,13 +393,26 @@ void kvm_gpc_deactivate(struct kvm *kvm, struct gfn_to_pfn_cache *gpc)
*/
write_lock_irq(&gpc->lock);
gpc->active = false;
+ gpc->valid = false;
+
+ /*
+ * Leave the GPA => uHVA cache intact, it's protected by the
+ * memslot generation. The PFN lookup needs to be redone every
+ * time as mmu_notifier protection is lost when the cache is
+ * removed from the VM's gpc_list.
+ */
+ old_khva = gpc->khva - offset_in_page(gpc->khva);
+ gpc->khva = NULL;
+
+ old_pfn = gpc->pfn;
+ gpc->pfn = KVM_PFN_ERR_FAULT;
write_unlock_irq(&gpc->lock);
spin_lock(&kvm->gpc_lock);
list_del(&gpc->list);
spin_unlock(&kvm->gpc_lock);
- kvm_gpc_unmap(kvm, gpc);
+ gpc_unmap_khva(old_pfn, old_khva);
}
}
EXPORT_SYMBOL_GPL(kvm_gpc_deactivate);