Tell resource manager to enable demand paging and wire vCPU faults to
provide the backing folio when a guestmemfd is bound to the faulting
access.
Signed-off-by: Elliot Berman <quic_eberman@xxxxxxxxxxx>
---
drivers/virt/gunyah/guest_memfd.c | 115 ++++++++++++++++++++++++++++++++++++++
drivers/virt/gunyah/gunyah_vcpu.c | 39 ++++++++++---
drivers/virt/gunyah/vm_mgr.c | 17 ++++++
drivers/virt/gunyah/vm_mgr.h | 3 +
4 files changed, 166 insertions(+), 8 deletions(-)
diff --git a/drivers/virt/gunyah/guest_memfd.c b/drivers/virt/gunyah/guest_memfd.c
index 5eeac6ac451e..4696ff4c7c22 100644
--- a/drivers/virt/gunyah/guest_memfd.c
+++ b/drivers/virt/gunyah/guest_memfd.c
@@ -843,3 +843,118 @@ int gunyah_gmem_reclaim_parcel(struct gunyah_vm *ghvm,
return 0;
}
+
+int gunyah_gmem_setup_demand_paging(struct gunyah_vm *ghvm)
+{
+ struct gunyah_rm_mem_entry *entries;
+ struct gunyah_gmem_binding *b;
+ unsigned long index = 0;
+ u32 count = 0, i;
+ int ret = 0;
+
+ down_read(&ghvm->bindings_lock);
+ mt_for_each(&ghvm->bindings, b, index, ULONG_MAX)
+ if (gunyah_guest_mem_is_lend(ghvm, b->flags))
+ count++;
+
+ if (!count)
+ goto out;
+
+ entries = kcalloc(count, sizeof(*entries), GFP_KERNEL);
+ if (!entries) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ index = i = 0;
+ mt_for_each(&ghvm->bindings, b, index, ULONG_MAX) {
+ if (!gunyah_guest_mem_is_lend(ghvm, b->flags))
+ continue;
+ entries[i].phys_addr = cpu_to_le64(gunyah_gfn_to_gpa(b->gfn));
+ entries[i].size = cpu_to_le64(b->nr << PAGE_SHIFT);
+ if (++i == count)
+ break;
+ }
+
+ ret = gunyah_rm_vm_set_demand_paging(ghvm->rm, ghvm->vmid, i, entries);
+ kfree(entries);
+out:
+ up_read(&ghvm->bindings_lock);
+ return ret;
+}
+
+static bool folio_mmapped(struct folio *folio)
+{
+ struct address_space *mapping = folio->mapping;
+ struct vm_area_struct *vma;
+ bool ret = false;
+
+ i_mmap_lock_read(mapping);
+ vma_interval_tree_foreach(vma, &mapping->i_mmap, folio_index(folio),
+ folio_index(folio) + folio_nr_pages(folio)) {
+ ret = true;
+ break;
+ }
+ i_mmap_unlock_read(mapping);
+ return ret;
+}
+
+int gunyah_gmem_demand_page(struct gunyah_vm *ghvm, u64 gpa, bool write)
+{
+ unsigned long gfn = gunyah_gpa_to_gfn(gpa);
+ struct gunyah_gmem_binding *b;
+ struct folio *folio;
+ int ret;
+
+ down_read(&ghvm->bindings_lock);
+ b = mtree_load(&ghvm->bindings, gfn);
+ if (!b) {
+ ret = -ENOENT;
+ goto unlock;
+ }
+
+ if (write && !(b->flags & GUNYAH_MEM_ALLOW_WRITE)) {
+ ret = -EPERM;
+ goto unlock;
+ }
+
+ folio = gunyah_gmem_get_folio(file_inode(b->file), gunyah_gfn_to_off(b, gfn));
+ if (IS_ERR(folio)) {
+ ret = PTR_ERR(folio);
+ pr_err_ratelimited(
+ "Failed to obtain memory for guest addr %016llx: %d\n",
+ gpa, ret);
+ goto unlock;
+ }
+
+ if (gunyah_guest_mem_is_lend(ghvm, b->flags) &&
+ (folio_mapped(folio) || folio_mmapped(folio))) {
+ ret = -EPERM;
+ goto out;
+ }
+
+ /**
+ * the folio covers the requested guest address, but the folio may not
+ * start at the requested guest address. recompute the gfn based on the
+ * folio itself.
+ */
+ gfn = gunyah_off_to_gfn(b, folio_index(folio));
+
+ ret = gunyah_vm_provide_folio(ghvm, folio, gfn,
+ !gunyah_guest_mem_is_lend(ghvm, b->flags),
+ !!(b->flags & GUNYAH_MEM_ALLOW_WRITE));
+ if (ret) {
+ if (ret != -EAGAIN)
+ pr_err_ratelimited(
+ "Failed to provide folio for guest addr: %016llx: %d\n",
+ gpa, ret);
+ goto out;
+ }
+out:
+ folio_unlock(folio);
+ folio_put(folio);
+unlock:
+ up_read(&ghvm->bindings_lock);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(gunyah_gmem_demand_page);
diff --git a/drivers/virt/gunyah/gunyah_vcpu.c b/drivers/virt/gunyah/gunyah_vcpu.c
index b636b54dc9a1..f01e6d6163ba 100644
--- a/drivers/virt/gunyah/gunyah_vcpu.c
+++ b/drivers/virt/gunyah/gunyah_vcpu.c
@@ -89,29 +89,44 @@ static irqreturn_t gunyah_vcpu_irq_handler(int irq, void *data)
return IRQ_HANDLED;
}
-static void gunyah_handle_page_fault(
+static bool gunyah_handle_page_fault(
struct gunyah_vcpu *vcpu,
const struct gunyah_hypercall_vcpu_run_resp *vcpu_run_resp)
{
u64 addr = vcpu_run_resp->state_data[0];
+ bool write = !!vcpu_run_resp->state_data[1];
+ int ret = 0;
+
+ ret = gunyah_gmem_demand_page(vcpu->ghvm, addr, write);
+ if (!ret || ret == -EAGAIN)
+ return true;
vcpu->vcpu_run->page_fault.resume_action = GUNYAH_VCPU_RESUME_FAULT;
- vcpu->vcpu_run->page_fault.attempt = 0;
+ vcpu->vcpu_run->page_fault.attempt = ret;
vcpu->vcpu_run->page_fault.phys_addr = addr;
vcpu->vcpu_run->exit_reason = GUNYAH_VCPU_EXIT_PAGE_FAULT;
+ return false;
}
-static void
-gunyah_handle_mmio(struct gunyah_vcpu *vcpu,
+static bool
+gunyah_handle_mmio(struct gunyah_vcpu *vcpu, unsigned long resume_data[3],
const struct gunyah_hypercall_vcpu_run_resp *vcpu_run_resp)
{
u64 addr = vcpu_run_resp->state_data[0],
len = vcpu_run_resp->state_data[1],
data = vcpu_run_resp->state_data[2];
+ int ret;
if (WARN_ON(len > sizeof(u64)))
len = sizeof(u64);
+ ret = gunyah_gmem_demand_page(vcpu->ghvm, addr,
+ vcpu->vcpu_run->mmio.is_write);
+ if (!ret || ret == -EAGAIN) {
+ resume_data[1] = GUNYAH_ADDRSPACE_VMMIO_ACTION_RETRY;
+ return true;
+ }
+
if (vcpu_run_resp->state == GUNYAH_VCPU_ADDRSPACE_VMMIO_READ) {
vcpu->vcpu_run->mmio.is_write = 0;
/* Record that we need to give vCPU user's supplied value next gunyah_vcpu_run() */
@@ -127,6 +142,8 @@ gunyah_handle_mmio(struct gunyah_vcpu *vcpu,
vcpu->mmio_addr = vcpu->vcpu_run->mmio.phys_addr = addr;
vcpu->vcpu_run->mmio.len = len;
vcpu->vcpu_run->exit_reason = GUNYAH_VCPU_EXIT_MMIO;
+
+ return false;
}
static int gunyah_handle_mmio_resume(struct gunyah_vcpu *vcpu,
@@ -147,6 +164,8 @@ static int gunyah_handle_mmio_resume(struct gunyah_vcpu *vcpu,
resume_data[1] = GUNYAH_ADDRSPACE_VMMIO_ACTION_FAULT;
break;
case GUNYAH_VCPU_RESUME_RETRY:
+ gunyah_gmem_demand_page(vcpu->ghvm, vcpu->mmio_addr,
+ vcpu->state == GUNYAH_VCPU_RUN_STATE_MMIO_WRITE);
resume_data[1] = GUNYAH_ADDRSPACE_VMMIO_ACTION_RETRY;
break;
default:
@@ -309,11 +328,15 @@ static int gunyah_vcpu_run(struct gunyah_vcpu *vcpu)
break;
case GUNYAH_VCPU_ADDRSPACE_VMMIO_READ:
case GUNYAH_VCPU_ADDRSPACE_VMMIO_WRITE:
- gunyah_handle_mmio(vcpu, &vcpu_run_resp);
- goto out;
+ if (!gunyah_handle_mmio(vcpu, resume_data,
+ &vcpu_run_resp))
+ goto out;
+ break;
case GUNYAH_VCPU_ADDRSPACE_PAGE_FAULT:
- gunyah_handle_page_fault(vcpu, &vcpu_run_resp);
- goto out;
+ if (!gunyah_handle_page_fault(vcpu,
+ &vcpu_run_resp))
+ goto out;
+ break;
default:
pr_warn_ratelimited(
"Unknown vCPU state: %llx\n",
diff --git a/drivers/virt/gunyah/vm_mgr.c b/drivers/virt/gunyah/vm_mgr.c
index 4379b5ba151e..3b767eeeb7c2 100644
--- a/drivers/virt/gunyah/vm_mgr.c
+++ b/drivers/virt/gunyah/vm_mgr.c
@@ -471,6 +471,23 @@ static int gunyah_vm_start(struct gunyah_vm *ghvm)
goto err;
}
+ ret = gunyah_gmem_setup_demand_paging(ghvm);
+ if (ret) {
+ dev_warn(ghvm->parent,
+ "Failed to set up gmem demand paging: %d\n", ret);
+ goto err;
+ }
+
+ ret = gunyah_rm_vm_set_address_layout(
+ ghvm->rm, ghvm->vmid, GUNYAH_RM_RANGE_ID_IMAGE,
+ ghvm->dtb.parcel_start << PAGE_SHIFT,
+ ghvm->dtb.parcel_pages << PAGE_SHIFT);
+ if (ret) {
+ dev_warn(ghvm->parent,
+ "Failed to set location of DTB mem parcel: %d\n", ret);
+ goto err;
+ }
+
ret = gunyah_rm_vm_init(ghvm->rm, ghvm->vmid);
if (ret) {
ghvm->vm_status = GUNYAH_RM_VM_STATUS_INIT_FAILED;
diff --git a/drivers/virt/gunyah/vm_mgr.h b/drivers/virt/gunyah/vm_mgr.h
index b2ab2f1bda3a..474ac866d237 100644
--- a/drivers/virt/gunyah/vm_mgr.h
+++ b/drivers/virt/gunyah/vm_mgr.h
@@ -137,4 +137,7 @@ int gunyah_gmem_reclaim_parcel(struct gunyah_vm *ghvm,
struct gunyah_rm_mem_parcel *parcel, u64 gfn,
u64 nr);
+int gunyah_gmem_setup_demand_paging(struct gunyah_vm *ghvm);
+int gunyah_gmem_demand_page(struct gunyah_vm *ghvm, u64 gpa, bool write);
+
#endif
--
2.34.1
