git: 658860e2d070 - main - xen/privcmd: implement the map resource ioctl

[Roger Pau Monné]

The branch main has been updated by royger:

URL: https://cgit.FreeBSD.org/src/commit/?id=658860e2d07065b4203bb3e7779bee0512c65c92

commit 658860e2d07065b4203bb3e7779bee0512c65c92
Author:     Roger Pau Monne <roger.pau at citrix.com>
AuthorDate: 2020-06-23 09:36:19 +0000
Commit:     Roger Pau Monné <royger at FreeBSD.org>
CommitDate: 2021-01-11 15:15:00 +0000

    xen/privcmd: implement the map resource ioctl
    
    The interface is mostly the same as the Linux ioctl, so that we don't
    need to modify the user-space libraries that make use of it.
    
    The ioctl is just a proxy for the XENMEM_acquire_resource hypercall.
    
    Sponsored by:   Citrix Systems R&D
---
 sys/dev/xen/privcmd/privcmd.c | 52 +++++++++++++++++++++++++++++++++++++++++++
 sys/xen/privcmd.h             | 15 +++++++++++++
 2 files changed, 67 insertions(+)

diff --git a/sys/dev/xen/privcmd/privcmd.c b/sys/dev/xen/privcmd/privcmd.c
index 78fb32444931..c31c31bcfe41 100644
--- a/sys/dev/xen/privcmd/privcmd.c
+++ b/sys/dev/xen/privcmd/privcmd.c
@@ -372,7 +372,59 @@ mmap_out:
 
 		break;
 	}
+	case IOCTL_PRIVCMD_MMAP_RESOURCE: {
+		struct ioctl_privcmd_mmapresource *mmap;
+		struct xen_mem_acquire_resource adq;
+		xen_pfn_t *gpfns;
+		struct privcmd_map *umap;
+
+		mmap = (struct ioctl_privcmd_mmapresource *)arg;
+
+		bzero(&adq, sizeof(adq));
+
+		adq.domid = mmap->dom;
+		adq.type = mmap->type;
+		adq.id = mmap->id;
+
+		/* Shortcut for getting the resource size. */
+		if (mmap->addr == 0 && mmap->num == 0) {
+			error = HYPERVISOR_memory_op(XENMEM_acquire_resource,
+			    &adq);
+			if (error != 0) {
+				error = xen_translate_error(error);
+				break;
+			}
+			error = copyout(&adq.nr_frames, &mmap->num,
+			    sizeof(mmap->num));
+			break;
+		}
 
+		umap = setup_virtual_area(td, mmap->addr, mmap->num);
+		if (umap == NULL) {
+			error = EINVAL;
+			break;
+		}
+
+		adq.nr_frames = mmap->num;
+		adq.frame = mmap->idx;
+
+		gpfns = malloc(sizeof(*gpfns) * mmap->num, M_PRIVCMD, M_WAITOK);
+		for (i = 0; i < mmap->num; i++)
+			gpfns[i] = atop(umap->phys_base_addr) + i;
+		set_xen_guest_handle(adq.frame_list, gpfns);
+
+		error = HYPERVISOR_memory_op(XENMEM_acquire_resource, &adq);
+		if (error != 0)
+			error = xen_translate_error(error);
+		else
+			umap->mapped = true;
+
+		free(gpfns, M_PRIVCMD);
+		if (!umap->mapped)
+			free(umap->err, M_PRIVCMD);
+
+		break;
+	}
 	default:
 		error = ENOSYS;
 		break;
diff --git a/sys/xen/privcmd.h b/sys/xen/privcmd.h
index a3cc4e110e41..ac2d0c00b845 100644
--- a/sys/xen/privcmd.h
+++ b/sys/xen/privcmd.h
@@ -50,9 +50,24 @@ struct ioctl_privcmd_mmapbatch {
 	int *err; /* array of error codes */
 };
 
+struct ioctl_privcmd_mmapresource {
+	domid_t dom; /* target domain */
+	unsigned int type; /* type of resource to map */
+	unsigned int id; /* type-specific resource identifier */
+	unsigned int idx; /* the index of the initial frame to be mapped */
+	unsigned long num; /* number of frames of the resource to be mapped */
+	unsigned long addr; /* physical address to map into */
+	/*
+	 * Note: issuing an ioctl with num = addr = 0 will return the size of
+	 * the resource.
+	 */
+};
+
 #define IOCTL_PRIVCMD_HYPERCALL					\
 	_IOWR('E', 0, struct ioctl_privcmd_hypercall)
 #define IOCTL_PRIVCMD_MMAPBATCH					\
 	_IOWR('E', 1, struct ioctl_privcmd_mmapbatch)
+#define IOCTL_PRIVCMD_MMAP_RESOURCE				\
+	_IOW('E', 2, struct ioctl_privcmd_mmapresource)
 
 #endif /* !__XEN_PRIVCMD_H__ */