diff options
| author | Fuad Tabba <tabba@google.com> | 2025-07-29 15:54:51 -0700 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2025-08-27 04:36:50 -0400 |
| commit | 32e200bd6e4407c31aef0392be041274bfa3f20e (patch) | |
| tree | 94cdf70a1769d1ec2da6835248328ad304c8b380 | |
| parent | f4e740309ee255a52a60bbc044647a11429250fc (diff) | |
KVM: arm64: Enable support for guest_memfd backed memory
Now that the infrastructure is in place, enable guest_memfd for arm64.
* Select CONFIG_KVM_GUEST_MEMFD in KVM/arm64 Kconfig.
* Enforce KVM_MEMSLOT_GMEM_ONLY for guest_memfd on arm64: Ensure that
guest_memfd-backed memory slots on arm64 are only supported if they
are intended for shared memory use cases (i.e.,
kvm_memslot_is_gmem_only() is true). This design reflects the current
arm64 KVM ecosystem where guest_memfd is primarily being introduced
for VMs that support shared memory.
Reviewed-by: James Houghton <jthoughton@google.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20250729225455.670324-21-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | arch/arm64/kvm/Kconfig | 1 | ||||
| -rw-r--r-- | arch/arm64/kvm/mmu.c | 7 |
2 files changed, 8 insertions, 0 deletions
diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig index 713248f240e0..bff62e75d681 100644 --- a/arch/arm64/kvm/Kconfig +++ b/arch/arm64/kvm/Kconfig @@ -37,6 +37,7 @@ menuconfig KVM select HAVE_KVM_VCPU_RUN_PID_CHANGE select SCHED_INFO select GUEST_PERF_EVENTS if PERF_EVENTS + select KVM_GUEST_MEMFD help Support hosting virtualized guest machines. diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index 5d73abc9bebc..a36426ccd9b5 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -2302,6 +2302,13 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm, if ((new->base_gfn + new->npages) > (kvm_phys_size(&kvm->arch.mmu) >> PAGE_SHIFT)) return -EFAULT; + /* + * Only support guest_memfd backed memslots with mappable memory, since + * there aren't any CoCo VMs that support only private memory on arm64. + */ + if (kvm_slot_has_gmem(new) && !kvm_memslot_is_gmem_only(new)) + return -EINVAL; + hva = new->userspace_addr; reg_end = hva + (new->npages << PAGE_SHIFT); |