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[src/trunk]: src Invert the mapping logic.
details: https://anonhg.NetBSD.org/src/rev/945f318203ca
branches: trunk
changeset: 995315:945f318203ca
user: maxv <maxv%NetBSD.org@localhost>
date: Sat Dec 15 13:39:43 2018 +0000
description:
Invert the mapping logic.
Until now, the "owner" of the memory was the guest, and by calling
nvmm_gpa_map(), the virtualizer was creating a view towards the guest
memory.
Qemu expects the contrary: it wants the owner to be the virtualizer, and
nvmm_gpa_map should just create a view from the guest towards the
virtualizer's address space. Under this scheme, it is legal to have two
GPAs that point to the same HVA.
Introduce nvmm_hva_map() and nvmm_hva_unmap(), that map/unamp the HVA into
a dedicated UOBJ. Change nvmm_gpa_map() and nvmm_gpa_unmap() to just
perform an enter into the desired UOBJ.
With this change in place, all the mapping-related problems in Qemu+NVMM
are fixed.
diffstat:
lib/libnvmm/libnvmm.3 | 45 +++++--
lib/libnvmm/libnvmm.c | 75 ++++++++----
lib/libnvmm/nvmm.h | 4 +-
sys/dev/nvmm/nvmm.c | 251 ++++++++++++++++++++++++++++++++++++------
sys/dev/nvmm/nvmm_internal.h | 14 ++-
sys/dev/nvmm/nvmm_ioctl.h | 18 ++-
6 files changed, 329 insertions(+), 78 deletions(-)
diffs (truncated from 622 to 300 lines):
diff -r 2e8a930c0d0c -r 945f318203ca lib/libnvmm/libnvmm.3
--- a/lib/libnvmm/libnvmm.3 Sat Dec 15 13:20:46 2018 +0000
+++ b/lib/libnvmm/libnvmm.3 Sat Dec 15 13:39:43 2018 +0000
@@ -1,4 +1,4 @@
-.\" $NetBSD: libnvmm.3,v 1.4 2018/12/12 11:40:08 wiz Exp $
+.\" $NetBSD: libnvmm.3,v 1.5 2018/12/15 13:39:43 maxv Exp $
.\"
.\" Copyright (c) 2018 The NetBSD Foundation, Inc.
.\" All rights reserved.
@@ -27,7 +27,7 @@
.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
.\" POSSIBILITY OF SUCH DAMAGE.
.\"
-.Dd December 12, 2018
+.Dd December 14, 2018
.Dt LIBNVMM 3
.Os
.Sh NAME
@@ -63,6 +63,10 @@
.Fn nvmm_vcpu_run "struct nvmm_machine *mach" "nvmm_cpuid_t cpuid" \
"struct nvmm_exit *exit"
.Ft int
+.Fn nvmm_hva_map "struct nvmm_machine *mach" "uintptr_t hva" "size_t size"
+.Ft int
+.Fn nvmm_hva_unmap "struct nvmm_machine *mach" "uintptr_t hva" "size_t size"
+.Ft int
.Fn nvmm_gpa_map "struct nvmm_machine *mach" "uintptr_t hva" "gpaddr_t gpa" \
"size_t size" "int flags"
.Ft int
@@ -164,15 +168,33 @@
structure is filled to indicate the exit reason, and the associated parameters
if any.
.Pp
-.Fn nvmm_gpa_map
-makes the guest physical memory area beginning on address
-.Fa gpa
-and of size
+.Fn nvmm_hva_map
+maps at address
+.Fa hva
+a buffer of size
+.Fa size
+in the calling process' virtual address space.
+This buffer is allowed to be subsequently mapped in a virtual machine.
+.Pp
+.Fn nvmm_hva_unmap
+unmaps the buffer of size
.Fa size
-available in the machine
-.Fa mach .
-The area is mapped in the calling process' virtual address space, at address
-.Fa hva .
+at address
+.Fa hva
+from the calling process' virtual address space.
+.Pp
+.Fn nvmm_gpa_map
+maps into the guest physical memory beginning on address
+.Fa gpa
+the buffer of size
+.Fa size
+located at address
+.Fa hva
+of the calling process' virtual address space.
+The
+.Fa hva
+parameter must point to a buffer that was previously mapped with
+.Fn nvmm_hva_map .
.Pp
.Fn nvmm_gpa_unmap
removes the guest physical memory area beginning on address
@@ -181,9 +203,6 @@
.Fa size
from the machine
.Fa mach .
-It also unmaps the area beginning on
-.Fa hva
-from the calling process' virtual address space.
.Pp
.Fn nvmm_gva_to_gpa
translates, on the CPU
diff -r 2e8a930c0d0c -r 945f318203ca lib/libnvmm/libnvmm.c
--- a/lib/libnvmm/libnvmm.c Sat Dec 15 13:20:46 2018 +0000
+++ b/lib/libnvmm/libnvmm.c Sat Dec 15 13:39:43 2018 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: libnvmm.c,v 1.4 2018/12/12 10:42:34 maxv Exp $ */
+/* $NetBSD: libnvmm.c,v 1.5 2018/12/15 13:39:43 maxv Exp $ */
/*
* Copyright (c) 2018 The NetBSD Foundation, Inc.
@@ -65,24 +65,12 @@
area_t *ent;
LIST_FOREACH(ent, areas, list) {
- /* Collision on HVA */
- if (hva >= ent->hva && hva < ent->hva + ent->size) {
- return false;
- }
- if (hva + size >= ent->hva &&
- hva + size < ent->hva + ent->size) {
- return false;
- }
- if (hva <= ent->hva && hva + size >= ent->hva + ent->size) {
- return false;
- }
-
/* Collision on GPA */
if (gpa >= ent->gpa && gpa < ent->gpa + ent->size) {
return false;
}
- if (gpa + size >= ent->gpa &&
- gpa + size < ent->gpa + ent->size) {
+ if (gpa + size > ent->gpa &&
+ gpa + size <= ent->gpa + ent->size) {
return false;
}
if (gpa <= ent->gpa && gpa + size >= ent->gpa + ent->size) {
@@ -434,12 +422,54 @@
args.size = size;
ret = ioctl(nvmm_fd, NVMM_IOC_GPA_UNMAP, &args);
+ if (ret == -1) {
+ /* Can't recover. */
+ abort();
+ }
+
+ return 0;
+}
+
+int
+nvmm_hva_map(struct nvmm_machine *mach, uintptr_t hva, size_t size)
+{
+ struct nvmm_ioc_hva_map args;
+ int ret;
+
+ if (nvmm_init() == -1) {
+ return -1;
+ }
+
+ args.machid = mach->machid;
+ args.hva = hva;
+ args.size = size;
+
+ ret = ioctl(nvmm_fd, NVMM_IOC_HVA_MAP, &args);
if (ret == -1)
return -1;
- ret = munmap((void *)hva, size);
+ return 0;
+}
+
+int
+nvmm_hva_unmap(struct nvmm_machine *mach, uintptr_t hva, size_t size)
+{
+ struct nvmm_ioc_hva_map args;
+ int ret;
- return ret;
+ if (nvmm_init() == -1) {
+ return -1;
+ }
+
+ args.machid = mach->machid;
+ args.hva = hva;
+ args.size = size;
+
+ ret = ioctl(nvmm_fd, NVMM_IOC_HVA_MAP, &args);
+ if (ret == -1)
+ return -1;
+
+ return 0;
}
/*
@@ -458,15 +488,10 @@
}
LIST_FOREACH(ent, areas, list) {
- if (gpa < ent->gpa) {
- continue;
+ if (gpa >= ent->gpa && gpa < ent->gpa + ent->size) {
+ *hva = ent->hva + (gpa - ent->gpa);
+ return 0;
}
- if (gpa >= ent->gpa + ent->size) {
- continue;
- }
-
- *hva = ent->hva + (gpa - ent->gpa);
- return 0;
}
errno = ENOENT;
diff -r 2e8a930c0d0c -r 945f318203ca lib/libnvmm/nvmm.h
--- a/lib/libnvmm/nvmm.h Sat Dec 15 13:20:46 2018 +0000
+++ b/lib/libnvmm/nvmm.h Sat Dec 15 13:39:43 2018 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: nvmm.h,v 1.2 2018/11/29 19:55:20 maxv Exp $ */
+/* $NetBSD: nvmm.h,v 1.3 2018/12/15 13:39:43 maxv Exp $ */
/*
* Copyright (c) 2018 The NetBSD Foundation, Inc.
@@ -83,6 +83,8 @@
int nvmm_gpa_map(struct nvmm_machine *, uintptr_t, gpaddr_t, size_t, int);
int nvmm_gpa_unmap(struct nvmm_machine *, uintptr_t, gpaddr_t, size_t);
+int nvmm_hva_map(struct nvmm_machine *, uintptr_t, size_t);
+int nvmm_hva_unmap(struct nvmm_machine *, uintptr_t, size_t);
int nvmm_gva_to_gpa(struct nvmm_machine *, nvmm_cpuid_t, gvaddr_t, gpaddr_t *,
nvmm_prot_t *);
diff -r 2e8a930c0d0c -r 945f318203ca sys/dev/nvmm/nvmm.c
--- a/sys/dev/nvmm/nvmm.c Sat Dec 15 13:20:46 2018 +0000
+++ b/sys/dev/nvmm/nvmm.c Sat Dec 15 13:39:43 2018 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: nvmm.c,v 1.3 2018/11/25 14:11:24 maxv Exp $ */
+/* $NetBSD: nvmm.c,v 1.4 2018/12/15 13:39:43 maxv Exp $ */
/*
* Copyright (c) 2018 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: nvmm.c,v 1.3 2018/11/25 14:11:24 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: nvmm.c,v 1.4 2018/12/15 13:39:43 maxv Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@@ -213,7 +213,14 @@
nvmm_vcpu_put(vcpu);
}
uvmspace_free(mach->vm);
- uao_detach(mach->uobj);
+
+ /* Drop the kernel UOBJ refs. */
+ for (j = 0; j < NVMM_MAX_SEGS; j++) {
+ if (!mach->segs[j].present)
+ continue;
+ uao_detach(mach->segs[j].uobj);
+ }
+
nvmm_machine_free(mach);
rw_exit(&mach->lock);
@@ -249,14 +256,13 @@
/* Curproc owns the machine. */
mach->procid = curproc->p_pid;
+ /* Zero out the segments. */
+ memset(&mach->segs, 0, sizeof(mach->segs));
+
/* Create the machine vmspace. */
mach->gpa_begin = 0;
mach->gpa_end = NVMM_MAX_RAM;
mach->vm = uvmspace_alloc(0, mach->gpa_end - mach->gpa_begin, false);
- mach->uobj = uao_create(mach->gpa_end - mach->gpa_begin, 0);
-
- /* Grab a reference for the machine. */
- uao_reference(mach->uobj);
(*nvmm_impl->machine_create)(mach);
@@ -292,7 +298,13 @@
/* Free the machine vmspace. */
uvmspace_free(mach->vm);
- uao_detach(mach->uobj);
+
+ /* Drop the kernel UOBJ refs. */
+ for (i = 0; i < NVMM_MAX_SEGS; i++) {
+ if (!mach->segs[i].present)
+ continue;
+ uao_detach(mach->segs[i].uobj);
+ }
nvmm_machine_free(mach);
nvmm_machine_put(mach);
@@ -500,22 +512,193 @@
/* -------------------------------------------------------------------------- */
+static struct uvm_object *
+nvmm_seg_getuobj(struct nvmm_machine *mach, uintptr_t hva, size_t size,
+ size_t *off)
+{
+ struct nvmm_seg *seg;
+ size_t i;
+
+ for (i = 0; i < NVMM_MAX_SEGS; i++) {
+ seg = &mach->segs[i];
+ if (!seg->present) {
+ continue;
+ }
+ if (hva >= seg->hva && hva + size <= seg->hva + seg->size) {
+ *off = hva - seg->hva;
+ return seg->uobj;
+ }
+ }
+
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