Return -EFAULT from user_mem_abort when the memslot flag is enabled and
fast GUP fails to find a present mapping for the page.
Signed-off-by: Anish Moorthy <amoorthy@xxxxxxxxxx>
---
Documentation/virt/kvm/api.rst | 2 +-
arch/arm64/kvm/arm.c | 1 +
arch/arm64/kvm/mmu.c | 11 +++++++++--
3 files changed, 11 insertions(+), 3 deletions(-)
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index 452bbca800b15..47f728701aca4 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -7712,7 +7712,7 @@ reported to the maintainers.
7.35 KVM_CAP_ABSENT_MAPPING_FAULT
---------------------------------
-:Architectures: x86
+:Architectures: x86, arm64
:Returns: -EINVAL.
The presence of this capability indicates that userspace may pass the
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index a932346b59f61..c9666d7c6c4ff 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -221,6 +221,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
case KVM_CAP_PTP_KVM:
case KVM_CAP_ARM_SYSTEM_SUSPEND:
case KVM_CAP_MEMORY_FAULT_INFO:
+ case KVM_CAP_ABSENT_MAPPING_FAULT:
r = 1;
break;
case KVM_CAP_SET_GUEST_DEBUG2:
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index d5ae636c26d62..26b9485557056 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1206,6 +1206,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
unsigned long vma_pagesize, fault_granule;
enum kvm_pgtable_prot prot = KVM_PGTABLE_PROT_R;
struct kvm_pgtable *pgt;
+ bool exit_on_memory_fault = kvm_slot_fault_on_absent_mapping(memslot);
fault_granule = 1UL << ARM64_HW_PGTABLE_LEVEL_SHIFT(fault_level);
write_fault = kvm_is_write_fault(vcpu);
@@ -1301,8 +1302,14 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
*/
smp_rmb();
- pfn = __gfn_to_pfn_memslot(memslot, gfn, false, false, NULL,
- write_fault, &writable, NULL);
+ pfn = __gfn_to_pfn_memslot(memslot, gfn, exit_on_memory_fault, false, NULL,
+ write_fault, &writable, NULL);
+
+ if (exit_on_memory_fault && pfn == KVM_PFN_ERR_FAULT) {
+ kvm_populate_efault_info(vcpu,
+ round_down(gfn * PAGE_SIZE, vma_pagesize), vma_pagesize);
+ return -EFAULT;
+ }
if (pfn == KVM_PFN_ERR_HWPOISON) {
kvm_send_hwpoison_signal(hva, vma_shift);
return 0;
--
2.40.0.577.gac1e443424-goog
