From: Ackerley Tng <ackerleytng@xxxxxxxxxx>
Update the KVM MMU fault handler to service guest page faults
for memory slots backed by guest_memfd with mmap support. For such
slots, the MMU must always fault in pages directly from guest_memfd,
bypassing the host's userspace_addr.
This ensures that guest_memfd-backed memory is always handled through
the guest_memfd specific faulting path, regardless of whether it's for
private or non-private (shared) use cases.
Additionally, rename kvm_mmu_faultin_pfn_private() to
kvm_mmu_faultin_pfn_gmem(), as this function is now used to fault in
pages from guest_memfd for both private and non-private memory,
accommodating the new use cases.
Co-developed-by: David Hildenbrand <david@xxxxxxxxxx>
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
Signed-off-by: Ackerley Tng <ackerleytng@xxxxxxxxxx>
Co-developed-by: Fuad Tabba <tabba@xxxxxxxxxx>
Signed-off-by: Fuad Tabba <tabba@xxxxxxxxxx>
[sean: drop the helper]
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/mmu/mmu.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index e83d666f32ad..56c80588efa0 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -4561,8 +4561,8 @@ static void kvm_mmu_finish_page_fault(struct kvm_vcpu *vcpu,
r == RET_PF_RETRY, fault->map_writable);
}
-static int kvm_mmu_faultin_pfn_private(struct kvm_vcpu *vcpu,
- struct kvm_page_fault *fault)
+static int kvm_mmu_faultin_pfn_gmem(struct kvm_vcpu *vcpu,
+ struct kvm_page_fault *fault)
{
int max_order, r;
@@ -4589,8 +4589,8 @@ static int __kvm_mmu_faultin_pfn(struct kvm_vcpu *vcpu,
{
unsigned int foll = fault->write ? FOLL_WRITE : 0;
- if (fault->is_private)
- return kvm_mmu_faultin_pfn_private(vcpu, fault);
+ if (fault->is_private || kvm_memslot_is_gmem_only(fault->slot))
+ return kvm_mmu_faultin_pfn_gmem(vcpu, fault);
foll |= FOLL_NOWAIT;
fault->pfn = __kvm_faultin_pfn(fault->slot, fault->gfn, foll,
--
2.50.1.552.g942d659e1b-goog
