Gunyah Resource Manager sets up a virtual machine based on a device
tree which lives in guest memory. Resource manager requires this memory
to be provided as a memory parcel for it to read and manipulate.
Implement a function to construct a memory parcel from the guest's
pinned memory pages.
Signed-off-by: Karim Manaouil <karim.manaouil@xxxxxxxxxx>
---
arch/arm64/kvm/gunyah.c | 80 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 80 insertions(+)
diff --git a/arch/arm64/kvm/gunyah.c b/arch/arm64/kvm/gunyah.c
index 7216db642174..ef0971146b56 100644
--- a/arch/arm64/kvm/gunyah.c
+++ b/arch/arm64/kvm/gunyah.c
@@ -634,6 +634,86 @@ static int gunyah_memory_reclaim_folio(struct gunyah_vm *ghvm,
return ret;
}
+static int gunyah_share_memory_parcel(struct gunyah_vm *ghvm,
+ struct gunyah_rm_mem_parcel *parcel, gfn_t gfn, u64 nr)
+{
+ struct kvm *kvm = &ghvm->kvm;
+ struct kvm_memory_slot *memslot;
+ struct page **pages;
+ int ret;
+ u64 i;
+
+ if (!nr)
+ return -EINVAL;
+
+ memslot = gfn_to_memslot(kvm, gfn);
+ if (!memslot)
+ return -ENOENT;
+
+ parcel->mem_entries = kcalloc(nr, sizeof(*parcel->mem_entries), GFP_KERNEL);
+ if (!parcel->mem_entries)
+ return -ENOMEM;
+ parcel->n_mem_entries = nr;
+
+ pages = memslot->arch.pages + (gfn - memslot->base_gfn);
+
+ for (i = 0; i < nr; i++) {
+ parcel->mem_entries[i].size = cpu_to_le64(PAGE_SIZE);
+ parcel->mem_entries[i].phys_addr = cpu_to_le64(page_to_phys(pages[i]));
+ }
+
+ parcel->n_acl_entries = 1;
+ parcel->acl_entries = kcalloc(parcel->n_acl_entries,
+ sizeof(*parcel->acl_entries), GFP_KERNEL);
+ if (!parcel->n_acl_entries) {
+ ret = -ENOMEM;
+ goto free_entries;
+ }
+ parcel->acl_entries[0].vmid = cpu_to_le16(ghvm->vmid);
+ parcel->acl_entries[0].perms |= GUNYAH_RM_ACL_R;
+ parcel->acl_entries[0].perms |= GUNYAH_RM_ACL_W;
+ parcel->acl_entries[0].perms |= GUNYAH_RM_ACL_X;
+ parcel->mem_handle = GUNYAH_MEM_HANDLE_INVAL;
+
+ ret = gunyah_rm_mem_share(ghvm->rm, parcel);
+ if (ret)
+ goto free_acl;
+
+ return ret;
+free_acl:
+ kfree(parcel->acl_entries);
+ parcel->acl_entries = NULL;
+free_entries:
+ kfree(parcel->mem_entries);
+ parcel->mem_entries = NULL;
+ parcel->n_mem_entries = 0;
+
+ return ret;
+}
+
+static int gunyah_reclaim_memory_parcel(struct gunyah_vm *ghvm,
+ struct gunyah_rm_mem_parcel *parcel, gfn_t gfn, u64 nr)
+{
+ int ret;
+
+ if (parcel->mem_handle != GUNYAH_MEM_HANDLE_INVAL) {
+ ret = gunyah_rm_mem_reclaim(ghvm->rm, parcel);
+ if (ret) {
+ dev_err(ghvm->parent, "Failed to reclaim parcel: %d\n",
+ ret);
+ /* We can't reclaim the pages -- hold onto the pages
+ * forever because we don't know what state the memory
+ * is in
+ */
+ return ret;
+ }
+ parcel->mem_handle = GUNYAH_MEM_HANDLE_INVAL;
+ kfree(parcel->mem_entries);
+ kfree(parcel->acl_entries);
+ }
+ return 0;
+}
+
int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
{
return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE;
--
2.39.5
