svn commit: r365265 - in head: share/man/man4 sys/amd64/amd64 sys/amd64/include sys/arm/arm sys/arm/include sys/arm64/arm64 sys/arm64/include sys/dev/mem sys/i386/i386 sys/i386/include sys/mips/inc...
Mark Johnston
markj at FreeBSD.org
Wed Sep 2 18:12:51 UTC 2020
Author: markj
Date: Wed Sep 2 18:12:47 2020
New Revision: 365265
URL: https://svnweb.freebsd.org/changeset/base/365265
Log:
Add the MEM_EXTRACT_PADDR ioctl to /dev/mem.
This allows privileged userspace processes to find information about the
physical page backing a given mapping. It is useful in applications
such as DPDK which perform some of their own memory management.
Reviewed by: kib, jhb (previous version)
MFC after: 2 weeks
Sponsored by: Juniper Networks, Inc.
Sponsored by: Klara Inc.
Differential Revision: https://reviews.freebsd.org/D26237
Modified:
head/share/man/man4/mem.4
head/sys/amd64/amd64/mem.c
head/sys/amd64/include/memdev.h
head/sys/arm/arm/mem.c
head/sys/arm/include/memdev.h
head/sys/arm64/arm64/mem.c
head/sys/arm64/include/memdev.h
head/sys/dev/mem/memdev.c
head/sys/i386/i386/mem.c
head/sys/i386/include/memdev.h
head/sys/mips/include/memdev.h
head/sys/mips/mips/mem.c
head/sys/powerpc/include/memdev.h
head/sys/powerpc/powerpc/mem.c
head/sys/riscv/include/memdev.h
head/sys/riscv/riscv/mem.c
head/sys/sys/memrange.h
Modified: head/share/man/man4/mem.4
==============================================================================
--- head/share/man/man4/mem.4 Wed Sep 2 18:04:49 2020 (r365264)
+++ head/share/man/man4/mem.4 Wed Sep 2 18:12:47 2020 (r365265)
@@ -28,7 +28,7 @@
.\" @(#)mem.4 5.3 (Berkeley) 5/2/91
.\" $FreeBSD$
.\"
-.Dd October 3, 2004
+.Dd August 25, 2020
.Dt MEM 4
.Os
.Sh NAME
@@ -54,11 +54,7 @@ in the same manner as
.Pa /dev/mem .
Only kernel virtual addresses that are currently mapped to memory are allowed.
.Pp
-On
-.Tn ISA
-the
-.Tn I/O
-memory space begins at physical address 0x000a0000
+On ISA the I/O memory space begins at physical address 0x000a0000
and runs to 0x00100000.
The
per-process data
@@ -69,6 +65,46 @@ is
long, and ends at virtual
address 0xf0000000.
.Sh IOCTL INTERFACE
+The
+.Dv MEM_EXTRACT_PADDR
+ioctl can be used to look up the physical address and NUMA domain of a given
+virtual address in the calling process' address space.
+The request is described by
+.Bd -literal
+struct mem_extract {
+ uint64_t me_vaddr; /* input */
+ uint64_t me_paddr; /* output */
+ int me_domain; /* output */
+ int me_state; /* output */
+};
+.Ed
+.Pp
+The ioctl returns an error if the address is not valid.
+The information returned by
+.Dv MEM_EXTRACT_PADDR
+may be out of date by the time that the ioctl call returns.
+Specifically, concurrent system calls, page faults, or system page reclamation
+activity may have unmapped the virtual page or replaced the backing physical
+page before the ioctl call returns.
+Wired pages, e.g., those locked by
+.Xr mlock 2 ,
+will not be reclaimed by the system.
+.Pp
+The
+.Fa me_state
+field provides information about the state of the virtual page:
+.Bl -tag -width indent
+.It Dv ME_STATE_INVALID
+The virtual address is invalid.
+.It Dv ME_STATE_VALID
+The virtual address is valid but is not mapped at the time of the ioctl call.
+.It Dv ME_STATE_MAPPED
+The virtual address corresponds to a physical page mapping, and the
+.Fa me_paddr
+and
+.Fa me_domain
+fields are valid.
+.Pp
Several architectures allow attributes to be associated with ranges of physical
memory.
These attributes can be manipulated via
@@ -95,12 +131,13 @@ The region cannot be written to.
.El
.Pp
Memory ranges are described by
-.Vt struct mem_range_desc :
-.Bd -literal -offset indent
-uint64_t mr_base; /\(** physical base address \(**/
-uint64_t mr_len; /\(** physical length of region \(**/
-int mr_flags; /\(** attributes of region \(**/
-char mr_owner[8];
+.Bd -literal
+struct mem_range_desc {
+ uint64_t mr_base; /* physical base address */
+ uint64_t mr_len; /* physical length of region */
+ int mr_flags; /* attributes of region */
+ char mr_owner[8];
+};
.Ed
.Pp
In addition to the region attributes listed above, the following flags
@@ -126,10 +163,11 @@ altered.
.El
.Pp
Operations are performed using
-.Fa struct mem_range_op :
-.Bd -literal -offset indent
-struct mem_range_desc *mo_desc;
-int mo_arg[2];
+.Bd -literal
+struct mem_range_op {
+ struct mem_range_desc *mo_desc;
+ int mo_arg[2];
+};
.Ed
.Pp
The
@@ -165,7 +203,7 @@ to remove a range.
.It Bq Er EOPNOTSUPP
Memory range operations are not supported on this architecture.
.It Bq Er ENXIO
-No memory range descriptors are available (e.g.\& firmware has not enabled
+No memory range descriptors are available (e.g., firmware has not enabled
any).
.It Bq Er EINVAL
The memory range supplied as an argument is invalid or overlaps another
@@ -174,7 +212,7 @@ range in a fashion not supported by this architecture.
An attempt to remove or update a range failed because the range is busy.
.It Bq Er ENOSPC
An attempt to create a new range failed due to a shortage of hardware
-resources (e.g.\& descriptor slots).
+resources (e.g., descriptor slots).
.It Bq Er ENOENT
An attempt to remove a range failed because no range matches the descriptor
base/length supplied.
Modified: head/sys/amd64/amd64/mem.c
==============================================================================
--- head/sys/amd64/amd64/mem.c Wed Sep 2 18:04:49 2020 (r365264)
+++ head/sys/amd64/amd64/mem.c Wed Sep 2 18:12:47 2020 (r365265)
@@ -185,9 +185,8 @@ memmmap(struct cdev *dev, vm_ooffset_t offset, vm_padd
* This is basically just an ioctl shim for mem_range_attr_get
* and mem_range_attr_set.
*/
-/* ARGSUSED */
int
-memioctl(struct cdev *dev __unused, u_long cmd, caddr_t data, int flags,
+memioctl_md(struct cdev *dev __unused, u_long cmd, caddr_t data, int flags,
struct thread *td)
{
int nd, error = 0;
Modified: head/sys/amd64/include/memdev.h
==============================================================================
--- head/sys/amd64/include/memdev.h Wed Sep 2 18:04:49 2020 (r365264)
+++ head/sys/amd64/include/memdev.h Wed Sep 2 18:12:47 2020 (r365265)
@@ -36,7 +36,7 @@
d_open_t memopen;
d_read_t memrw;
-d_ioctl_t memioctl;
+d_ioctl_t memioctl_md;
d_mmap_t memmmap;
#endif /* _MACHINE_MEMDEV_H_ */
Modified: head/sys/arm/arm/mem.c
==============================================================================
--- head/sys/arm/arm/mem.c Wed Sep 2 18:04:49 2020 (r365264)
+++ head/sys/arm/arm/mem.c Wed Sep 2 18:12:47 2020 (r365265)
@@ -172,3 +172,10 @@ memmmap(struct cdev *dev, vm_ooffset_t offset, vm_padd
}
return (-1);
}
+
+int
+memioctl_md(struct cdev *dev __unused, u_long cmd __unused,
+ caddr_t data __unused, int flags __unused, struct thread *td __unused)
+{
+ return (ENOTTY);
+}
Modified: head/sys/arm/include/memdev.h
==============================================================================
--- head/sys/arm/include/memdev.h Wed Sep 2 18:04:49 2020 (r365264)
+++ head/sys/arm/include/memdev.h Wed Sep 2 18:12:47 2020 (r365265)
@@ -37,6 +37,6 @@
d_open_t memopen;
d_read_t memrw;
d_mmap_t memmmap;
-#define memioctl (d_ioctl_t *)NULL
+d_ioctl_t memioctl_md;
#endif /* _MACHINE_MEMDEV_H_ */
Modified: head/sys/arm64/arm64/mem.c
==============================================================================
--- head/sys/arm64/arm64/mem.c Wed Sep 2 18:04:49 2020 (r365264)
+++ head/sys/arm64/arm64/mem.c Wed Sep 2 18:12:47 2020 (r365265)
@@ -129,3 +129,10 @@ memmmap(struct cdev *dev, vm_ooffset_t offset, vm_padd
}
return (-1);
}
+
+int
+memioctl_md(struct cdev *dev __unused, u_long cmd __unused,
+ caddr_t data __unused, int flags __unused, struct thread *td __unused)
+{
+ return (ENOTTY);
+}
Modified: head/sys/arm64/include/memdev.h
==============================================================================
--- head/sys/arm64/include/memdev.h Wed Sep 2 18:04:49 2020 (r365264)
+++ head/sys/arm64/include/memdev.h Wed Sep 2 18:12:47 2020 (r365265)
@@ -34,7 +34,7 @@
d_open_t memopen;
d_read_t memrw;
-#define memioctl (d_ioctl_t *)NULL
+d_ioctl_t memioctl_md;
d_mmap_t memmmap;
#endif /* _MACHINE_MEMDEV_H_ */
Modified: head/sys/dev/mem/memdev.c
==============================================================================
--- head/sys/dev/mem/memdev.c Wed Sep 2 18:04:49 2020 (r365264)
+++ head/sys/dev/mem/memdev.c Wed Sep 2 18:12:47 2020 (r365265)
@@ -33,6 +33,7 @@ __FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/conf.h>
#include <sys/fcntl.h>
+#include <sys/ioccom.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
@@ -46,12 +47,19 @@ __FBSDID("$FreeBSD$");
#include <sys/uio.h>
#include <vm/vm.h>
+#include <vm/vm_param.h>
#include <vm/pmap.h>
+#include <vm/vm_map.h>
+#include <vm/vm_object.h>
+#include <vm/vm_page.h>
+#include <vm/vm_phys.h>
#include <machine/memdev.h>
static struct cdev *memdev, *kmemdev;
+static d_ioctl_t memioctl;
+
static struct cdevsw mem_cdevsw = {
.d_version = D_VERSION,
.d_flags = D_MEM,
@@ -79,6 +87,43 @@ memopen(struct cdev *dev __unused, int flags, int fmt
error = securelevel_gt(td->td_ucred, 0);
}
+ return (error);
+}
+
+static int
+memioctl(struct cdev *dev, u_long cmd, caddr_t data, int flags,
+ struct thread *td)
+{
+ vm_map_t map;
+ vm_map_entry_t entry;
+ struct mem_extract *me;
+ int error;
+
+ error = 0;
+ switch (cmd) {
+ case MEM_EXTRACT_PADDR:
+ me = (struct mem_extract *)data;
+
+ map = &td->td_proc->p_vmspace->vm_map;
+ vm_map_lock_read(map);
+ if (vm_map_lookup_entry(map, me->me_vaddr, &entry)) {
+ me->me_paddr = pmap_extract(
+ &td->td_proc->p_vmspace->vm_pmap, me->me_vaddr);
+ if (me->me_paddr != 0) {
+ me->me_state = ME_STATE_MAPPED;
+ me->me_domain = _vm_phys_domain(me->me_paddr);
+ } else {
+ me->me_state = ME_STATE_VALID;
+ }
+ } else {
+ me->me_state = ME_STATE_INVALID;
+ }
+ vm_map_unlock_read(map);
+ break;
+ default:
+ error = memioctl_md(dev, cmd, data, flags, td);
+ break;
+ }
return (error);
}
Modified: head/sys/i386/i386/mem.c
==============================================================================
--- head/sys/i386/i386/mem.c Wed Sep 2 18:04:49 2020 (r365264)
+++ head/sys/i386/i386/mem.c Wed Sep 2 18:12:47 2020 (r365265)
@@ -176,9 +176,8 @@ memmmap(struct cdev *dev, vm_ooffset_t offset, vm_padd
* This is basically just an ioctl shim for mem_range_attr_get
* and mem_range_attr_set.
*/
-/* ARGSUSED */
int
-memioctl(struct cdev *dev __unused, u_long cmd, caddr_t data, int flags,
+memioctl_md(struct cdev *dev __unused, u_long cmd, caddr_t data, int flags,
struct thread *td)
{
int nd, error = 0;
Modified: head/sys/i386/include/memdev.h
==============================================================================
--- head/sys/i386/include/memdev.h Wed Sep 2 18:04:49 2020 (r365264)
+++ head/sys/i386/include/memdev.h Wed Sep 2 18:12:47 2020 (r365265)
@@ -36,7 +36,7 @@
d_open_t memopen;
d_read_t memrw;
-d_ioctl_t memioctl;
+d_ioctl_t memioctl_md;
d_mmap_t memmmap;
#endif /* _MACHINE_MEMDEV_H_ */
Modified: head/sys/mips/include/memdev.h
==============================================================================
--- head/sys/mips/include/memdev.h Wed Sep 2 18:04:49 2020 (r365264)
+++ head/sys/mips/include/memdev.h Wed Sep 2 18:12:47 2020 (r365265)
@@ -37,7 +37,7 @@
d_open_t memopen;
d_read_t memrw;
-#define memioctl (d_ioctl_t *)NULL
+d_ioctl_t memioctl_md;
d_mmap_t memmmap;
#endif /* _MACHINE_MEMDEV_H_ */
Modified: head/sys/mips/mips/mem.c
==============================================================================
--- head/sys/mips/mips/mem.c Wed Sep 2 18:04:49 2020 (r365264)
+++ head/sys/mips/mips/mem.c Wed Sep 2 18:12:47 2020 (r365265)
@@ -160,3 +160,10 @@ memmmap(struct cdev *dev, vm_ooffset_t offset, vm_padd
return (0);
}
+
+int
+memioctl_md(struct cdev *dev __unused, u_long cmd __unused,
+ caddr_t data __unused, int flags __unused, struct thread *td __unused)
+{
+ return (ENOTTY);
+}
Modified: head/sys/powerpc/include/memdev.h
==============================================================================
--- head/sys/powerpc/include/memdev.h Wed Sep 2 18:04:49 2020 (r365264)
+++ head/sys/powerpc/include/memdev.h Wed Sep 2 18:12:47 2020 (r365265)
@@ -36,7 +36,7 @@
d_open_t memopen;
d_read_t memrw;
-d_ioctl_t memioctl;
+d_ioctl_t memioctl_md;
d_mmap_t memmmap;
#endif /* _MACHINE_MEMDEV_H_ */
Modified: head/sys/powerpc/powerpc/mem.c
==============================================================================
--- head/sys/powerpc/powerpc/mem.c Wed Sep 2 18:04:49 2020 (r365264)
+++ head/sys/powerpc/powerpc/mem.c Wed Sep 2 18:12:47 2020 (r365265)
@@ -278,9 +278,8 @@ ppc_mrset(struct mem_range_softc *sc, struct mem_range
* This is basically just an ioctl shim for mem_range_attr_get
* and mem_range_attr_set.
*/
-/* ARGSUSED */
int
-memioctl(struct cdev *dev __unused, u_long cmd, caddr_t data, int flags,
+memioctl_md(struct cdev *dev __unused, u_long cmd, caddr_t data, int flags,
struct thread *td)
{
int nd, error = 0;
Modified: head/sys/riscv/include/memdev.h
==============================================================================
--- head/sys/riscv/include/memdev.h Wed Sep 2 18:04:49 2020 (r365264)
+++ head/sys/riscv/include/memdev.h Wed Sep 2 18:12:47 2020 (r365265)
@@ -34,7 +34,7 @@
d_open_t memopen;
d_read_t memrw;
-#define memioctl (d_ioctl_t *)NULL
+d_ioctl_t memioctl_md;
#define memmmap (d_mmap_t *)NULL
#endif /* _MACHINE_MEMDEV_H_ */
Modified: head/sys/riscv/riscv/mem.c
==============================================================================
--- head/sys/riscv/riscv/mem.c Wed Sep 2 18:04:49 2020 (r365264)
+++ head/sys/riscv/riscv/mem.c Wed Sep 2 18:12:47 2020 (r365265)
@@ -121,3 +121,10 @@ memrw(struct cdev *dev, struct uio *uio, int flags)
return (error);
}
+
+int
+memioctl_md(struct cdev *dev __unused, u_long cmd __unused,
+ caddr_t data __unused, int flags __unused, struct thread *td __unused)
+{
+ return (ENOTTY);
+}
Modified: head/sys/sys/memrange.h
==============================================================================
--- head/sys/sys/memrange.h Wed Sep 2 18:04:49 2020 (r365264)
+++ head/sys/sys/memrange.h Wed Sep 2 18:12:47 2020 (r365265)
@@ -45,6 +45,20 @@ struct mem_range_op
#define MEMRANGE_GET _IOWR('m', 50, struct mem_range_op)
#define MEMRANGE_SET _IOW('m', 51, struct mem_range_op)
+#define ME_STATE_INVALID 0
+#define ME_STATE_VALID 1
+#define ME_STATE_MAPPED 2
+
+struct mem_extract {
+ uint64_t me_vaddr;
+ uint64_t me_paddr;
+ int me_domain;
+ int me_state;
+ uint64_t pad1[5];
+};
+
+#define MEM_EXTRACT_PADDR _IOWR('m', 52, struct mem_extract)
+
#ifdef _KERNEL
MALLOC_DECLARE(M_MEMDESC);
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