[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Xen-devel] [Qemu-devel] [PATCH v5 3/6] Qemu-Xen-vTPM: Xen frontend driver infrastructure
On 04/10/2015 02:59 AM, Quan Xu wrote:
This patch adds infrastructure for xen front drivers living in qemu,
so drivers don't need to implement common stuff on their own. It's
mostly xenbus management stuff: some functions to access XenStore,
setting up XenStore watches, callbacks on device discovery and state
changes, and handle event channel between the virtual machines.
Call xen_fe_register() function to register XenDevOps, and make sure,
[...]
3 = ""
[...]
device = "" (frontend device, the backend is running in QEMU/.etc)
vkbd = ""
[...]
vif = ""
[...]
..
(QEMU) xen_vtpmdev_ops is initialized with the following process:
xen_hvm_init()
[...]
-->xen_fe_register("vtpm", ...)
-->xenstore_fe_scan()
-->xen_fe_try_init(ops)
--> XenDevOps.init()
-->xen_fe_get_xendev()
--> XenDevOps.alloc()
-->xen_fe_check()
-->xen_fe_try_initialise()
--> XenDevOps.initialise()
-->xen_fe_try_connected()
--> XenDevOps.connected()
-->xs_watch()
[...]
Signed-off-by: Quan Xu <quan.xu@xxxxxxxxx>
--Changes in v5:
-Comments enhancement.
-Pass the size of the buff for vtpm_recv()|vtpm_send().
---
hw/tpm/Makefile.objs | 1 +
hw/tpm/xen_vtpm_frontend.c | 321 +++++++++++++++++++++++++++++++++++++++++++
hw/xen/xen_frontend.c | 20 +++
include/hw/xen/xen_backend.h | 7 +
include/hw/xen/xen_common.h | 6 +
xen-hvm.c | 5 +
6 files changed, 360 insertions(+)
create mode 100644 hw/tpm/xen_vtpm_frontend.c
diff --git a/hw/tpm/Makefile.objs b/hw/tpm/Makefile.objs
index 99f5983..57919fa 100644
--- a/hw/tpm/Makefile.objs
+++ b/hw/tpm/Makefile.objs
@@ -1,2 +1,3 @@
common-obj-$(CONFIG_TPM_TIS) += tpm_tis.o
common-obj-$(CONFIG_TPM_PASSTHROUGH) += tpm_passthrough.o
+common-obj-$(CONFIG_TPM_XENSTUBDOMS) += xen_vtpm_frontend.o
diff --git a/hw/tpm/xen_vtpm_frontend.c b/hw/tpm/xen_vtpm_frontend.c
new file mode 100644
index 0000000..3ca9501
--- /dev/null
+++ b/hw/tpm/xen_vtpm_frontend.c
@@ -0,0 +1,321 @@
+/*
+ * Connect to Xen vTPM stubdom domain
+ *
+ * Copyright (c) 2015 Intel Corporation
+ * Authors:
+ * Quan Xu <quan.xu@xxxxxxxxx>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <string.h>
+#include <unistd.h>
+#include <signal.h>
+#include <inttypes.h>
+#include <time.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <sys/uio.h>
+
+#include "hw/hw.h"
+#include "block/aio.h"
+#include "hw/xen/xen_backend.h"
+
+#ifndef XS_STUBDOM_VTPM_ENABLE
+#define XS_STUBDOM_VTPM_ENABLE "1"
+#endif
+
+#ifndef PAGE_SIZE
+#define PAGE_SIZE 4096
+#endif
+
+enum tpmif_state {
+ /* No contents, vTPM idle, cancel complete */
+ TPMIF_STATE_IDLE,
+ /* Request ready or vTPM working */
+ TPMIF_STATE_SUBMIT,
+ /* Response ready or vTPM idle */
+ TPMIF_STATE_FINISH,
+ /* Cancel requested or vTPM working */
+ TPMIF_STATE_CANCEL,
+};
+
+static AioContext *vtpm_aio_ctx;
+
+enum status_bits {
+ VTPM_STATUS_RUNNING = 0x1,
+ VTPM_STATUS_IDLE = 0x2,
+ VTPM_STATUS_RESULT = 0x4,
+ VTPM_STATUS_CANCELED = 0x8,
+};
+
+struct tpmif_shared_page {
+ /* Request and response length in bytes */
+ uint32_t length;
+ /* Enum tpmif_state */
+ uint8_t state;
+ /* For the current request */
+ uint8_t locality;
+ /* Should be zero */
+ uint8_t pad;
+ /* Extra pages for long packets; may be zero */
+ uint8_t nr_extra_pages;
+ /*
+ * Grant IDs, the length is actually nr_extra_pages.
+ * beyond the extra_pages entries is the actual requese
+ * and response.
+ */
requese->request
+ uint32_t extra_pages[0];
+};
+
+struct xen_vtpm_dev {
+ struct XenDevice xendev; /* must be first */
+ struct tpmif_shared_page *shr;
+ xc_gntshr *xen_xcs;
+ int ring_ref;
+ int bedomid;
+ QEMUBH *sr_bh;
+};
+
+static uint8_t vtpm_status(struct xen_vtpm_dev *vtpmdev)
+{
+ switch (vtpmdev->shr->state) {
+ case TPMIF_STATE_IDLE:
+ case TPMIF_STATE_FINISH:
+ return VTPM_STATUS_IDLE;
+ case TPMIF_STATE_SUBMIT:
+ case TPMIF_STATE_CANCEL:
+ return VTPM_STATUS_RUNNING;
+ default:
+ return 0;
+ }
+}
+
+static bool vtpm_aio_wait(AioContext *ctx)
+{
+ return aio_poll(ctx, true);
+}
+
+static void sr_bh_handler(void *opaque)
+{
+}
+
+int vtpm_recv(struct XenDevice *xendev, uint8_t* buf, uint32_t buf_size,
+ size_t *count)
+{
+ struct xen_vtpm_dev *vtpmdev = container_of(xendev, struct xen_vtpm_dev,
+ xendev);
+ struct tpmif_shared_page *shr = vtpmdev->shr;
+ unsigned int offset;
+ size_t length = shr->length;
+
+ if (shr->state == TPMIF_STATE_IDLE) {
+ return -ECANCELED;
+ }
+
+ offset = sizeof(*shr) + sizeof(shr->extra_pages[0])*shr->nr_extra_pages;
offset now points to where the TPM response starts, right?
+ if (offset > buf_size) {
You are comparing offset as if it was the size of the TPM response, but
that's not what it is as far as I understand this.
I would have thought that shr->length indicates the size of the TPM
response that starts at offset.
So then you should only have to ensure that shr->length <= buf_size and
never copy more than buf_size bytes to buf.
Similar comments to vtpm_send.
+ return -EIO;
+ }
+
+ if (offset + length > buf_size) {
+ length = buf_size - offset;
+ }
+
+ if (length > *count) {
+ length = *count;
+ }
+
+ memcpy(buf, offset + (uint8_t *)shr, shr->length);
use length rather than shr->length otherwise length goes unused.
Rest looks good.
Stefan
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel
|
