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 <[email protected]>
---
drivers/virt/gunyah/guest_memfd.c | 94 +++++++++++++++++++++++++++++++++++++++
drivers/virt/gunyah/gunyah_vcpu.c | 41 +++++++++++++----
drivers/virt/gunyah/vm_mgr.c | 29 ++++++++++++
drivers/virt/gunyah/vm_mgr.h | 3 ++
4 files changed, 159 insertions(+), 8 deletions(-)
diff --git a/drivers/virt/gunyah/guest_memfd.c b/drivers/virt/gunyah/guest_memfd.c
index 0c35ffa616d9c..797bc29a520bc 100644
--- a/drivers/virt/gunyah/guest_memfd.c
+++ b/drivers/virt/gunyah/guest_memfd.c
@@ -891,3 +891,97 @@ 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;
+}
+
+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 (!folio) {
+ ret = -ENOMEM;
+ pr_err_ratelimited("Failed to obtain memory for guest addr %016llx\n", gpa);
+ goto unlock;
+ }
+
+ /**
+ * 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));
+
+ filemap_invalidate_lock_shared(b->file->f_mapping);
+ ret = gunyah_vm_provide_folio(ghvm, folio, gfn,
+ !gunyah_guest_mem_is_lend(ghvm, b->flags),
+ !!(b->flags & GUNYAH_MEM_ALLOW_WRITE));
+ filemap_invalidate_unlock_shared(b->file->f_mapping);
+ 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 8192350f180b0..f8306620b1dd6 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() */
@@ -128,11 +143,15 @@ 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,
unsigned long resume_data[3])
{
+ bool write = vcpu->state == GUNYAH_VCPU_RUN_STATE_MMIO_WRITE;
+
switch (vcpu->vcpu_run->mmio.resume_action) {
case GUNYAH_VCPU_RESUME_HANDLED:
if (vcpu->state == GUNYAH_VCPU_RUN_STATE_MMIO_READ) {
@@ -148,6 +167,8 @@ static int gunyah_handle_mmio_resume(struct gunyah_vcpu *vcpu,
resume_data[1] = GUNYAH_ADDRSPACE_VMMIO_ACTION_FAULT;
break;
case GUNYAH_VCPU_RESUME_RETRY:
+ /* userspace probably added a memory binding */
+ gunyah_gmem_demand_page(vcpu->ghvm, vcpu->mmio_addr, write);
resume_data[1] = GUNYAH_ADDRSPACE_VMMIO_ACTION_RETRY;
break;
default:
@@ -310,11 +331,15 @@ 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 198a99d78c44c..473740a1f97d0 100644
--- a/drivers/virt/gunyah/vm_mgr.c
+++ b/drivers/virt/gunyah/vm_mgr.c
@@ -474,6 +474,23 @@ 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;
@@ -501,8 +518,20 @@ static int gunyah_vm_start(struct gunyah_vm *ghvm)
gunyah_vm_add_resource(ghvm, ghrsc);
}
+ ret = gunyah_vm_parcel_to_paged(ghvm, &ghvm->dtb.parcel,
+ ghvm->dtb.parcel_start,
+ ghvm->dtb.parcel_pages);
+ if (ret)
+ goto err;
+
ret = gunyah_rm_vm_start(ghvm->rm, ghvm->vmid);
if (ret) {
+ /**
+ * need to rollback parcel_to_paged because RM is still
+ * tracking the parcel
+ */
+ gunyah_vm_mm_erase_range(ghvm, ghvm->dtb.parcel_start,
+ ghvm->dtb.parcel_pages);
dev_warn(ghvm->parent, "Failed to start VM: %d\n", ret);
goto err;
}
diff --git a/drivers/virt/gunyah/vm_mgr.h b/drivers/virt/gunyah/vm_mgr.h
index d8c299e5cf7cc..5eb14f30ba965 100644
--- a/drivers/virt/gunyah/vm_mgr.h
+++ b/drivers/virt/gunyah/vm_mgr.h
@@ -199,4 +199,7 @@ 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