Handle the "no memslot" case at the beginning of kvm_faultin_pfn(), just
after the private versus shared check, so that there's no need to
repeatedly query whether or not a slot exists. This also makes it more
obvious that, except for private vs. shared attributes, the process of
faulting in a pfn simply doesn't apply to gfns without a slot.
Cc: David Matlack <dmatlack@xxxxxxxxxx>
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/mmu/mmu.c | 33 ++++++++++++++++++---------------
arch/x86/kvm/mmu/mmu_internal.h | 5 ++++-
2 files changed, 22 insertions(+), 16 deletions(-)
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 505fc7eef533..7a2874756b3f 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -3278,6 +3278,14 @@ static int direct_map(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
return ret;
}
+static void kvm_mmu_prepare_memory_fault_exit(struct kvm_vcpu *vcpu,
+ struct kvm_page_fault *fault)
+{
+ kvm_prepare_memory_fault_exit(vcpu, fault->gfn << PAGE_SHIFT,
+ PAGE_SIZE, fault->write, fault->exec,
+ fault->is_private);
+}
+
static void kvm_send_hwpoison_signal(struct kvm_memory_slot *slot, gfn_t gfn)
{
unsigned long hva = gfn_to_hva_memslot(slot, gfn);
@@ -3314,9 +3322,16 @@ static int kvm_handle_noslot_fault(struct kvm_vcpu *vcpu,
{
gva_t gva = fault->is_tdp ? 0 : fault->addr;
+ if (fault->is_private) {
+ kvm_mmu_prepare_memory_fault_exit(vcpu, fault);
+ return -EFAULT;
+ }
+
vcpu_cache_mmio_info(vcpu, gva, fault->gfn,
access & shadow_mmio_access_mask);
+ fault->pfn = KVM_PFN_NOSLOT;
+
/*
* If MMIO caching is disabled, emulate immediately without
* touching the shadow page tables as attempting to install an
@@ -4296,14 +4311,6 @@ static inline u8 kvm_max_level_for_order(int order)
return PG_LEVEL_4K;
}
-static void kvm_mmu_prepare_memory_fault_exit(struct kvm_vcpu *vcpu,
- struct kvm_page_fault *fault)
-{
- kvm_prepare_memory_fault_exit(vcpu, fault->gfn << PAGE_SHIFT,
- PAGE_SIZE, fault->write, fault->exec,
- fault->is_private);
-}
-
static int kvm_faultin_pfn_private(struct kvm_vcpu *vcpu,
struct kvm_page_fault *fault)
{
@@ -4376,12 +4383,12 @@ static int kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault,
return -EFAULT;
}
+ if (unlikely(!slot))
+ return kvm_handle_noslot_fault(vcpu, fault, access);
+
fault->mmu_seq = vcpu->kvm->mmu_invalidate_seq;
smp_rmb();
- if (!slot)
- goto faultin_pfn;
-
/*
* Retry the page fault if the gfn hit a memslot that is being deleted
* or moved. This ensures any existing SPTEs for the old memslot will
@@ -4434,7 +4441,6 @@ static int kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault,
if (mmu_invalidate_retry_gfn_unsafe(vcpu->kvm, fault->mmu_seq, fault->gfn))
return RET_PF_RETRY;
-faultin_pfn:
ret = __kvm_faultin_pfn(vcpu, fault);
if (ret != RET_PF_CONTINUE)
return ret;
@@ -4442,9 +4448,6 @@ static int kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault,
if (unlikely(is_error_pfn(fault->pfn)))
return kvm_handle_error_pfn(vcpu, fault);
- if (unlikely(!slot))
- return kvm_handle_noslot_fault(vcpu, fault, access);
-
/*
* Check again for a relevant mmu_notifier invalidation event purely to
* avoid contending mmu_lock. Most invalidations will be detected by
diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h
index 0669a8a668ca..bd7d07e6c697 100644
--- a/arch/x86/kvm/mmu/mmu_internal.h
+++ b/arch/x86/kvm/mmu/mmu_internal.h
@@ -235,7 +235,10 @@ struct kvm_page_fault {
/* The memslot containing gfn. May be NULL. */
struct kvm_memory_slot *slot;
- /* Outputs of kvm_faultin_pfn. */
+ /*
+ * Outputs of kvm_faultin_pfn, guaranteed to be valid if and only if
+ * slot is non-NULL.
+ */
unsigned long mmu_seq;
kvm_pfn_t pfn;
hva_t hva;
--
2.43.0.687.g38aa6559b0-goog
