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Re: [Xen-devel] [PATCH v4 3/5] Qemu-Xen-vTPM: Register Xen stubdom vTPM frontend driver
- To: Quan Xu <quan.xu@xxxxxxxxx>, stefano.stabellini@xxxxxxxxxxxxx, qemu-devel@xxxxxxxxxx, armbru@xxxxxxxxxx, lcapitulino@xxxxxxxxxx, aliguori@xxxxxxxxxx, pbonzini@xxxxxxxxxx, eblake@xxxxxxxxxx, kraxel@xxxxxxxxxx, meyering@xxxxxxxxxx, mjt@xxxxxxxxxx, sw@xxxxxxxxxxx, wei.liu2@xxxxxxxxxx
- From: Stefan Berger <stefanb@xxxxxxxxxxxxxxxxxx>
- Date: Wed, 18 Mar 2015 14:59:21 -0400
- Cc: xen-devel@xxxxxxxxxxxxx
- Delivery-date: Wed, 18 Mar 2015 19:00:43 +0000
- List-id: Xen developer discussion <xen-devel.lists.xen.org>
On 03/10/2015 08:14 AM, Quan Xu wrote:
This drvier transfers any request/repond between TPM xenstubdoms
driver and Xen vTPM stubdom, and facilitates communications between
Xen vTPM stubdom domain and vTPM xenstubdoms driver. It is a glue for
the TPM xenstubdoms driver and Xen stubdom vTPM domain that provides
the actual TPM functionality.
(Xen) Xen backend driver should run before running this frontend, and
initialize XenStore as the following for communication.
[XenStore]
for example:
Domain 0: runs QEMU for guest A
Domain 1: vtpmmgr
Domain 2: vTPM for guest A
Domain 3: HVM guest A
[...]
local = ""
domain = ""
0 = ""
frontend = ""
vtpm = ""
2 = ""
0 = ""
backend = "/local/domain/2/backend/vtpm/0/0"
backend-id = "2"
state = "*"
handle = "0"
domain = "Domain3's name"
ring-ref = "*"
event-channel = "*"
feature-protocol-v2 = "1"
backend = ""
qdisk = ""
[...]
console = ""
vif = ""
[...]
2 = ""
[...]
backend = ""
vtpm = ""
0 = ""
0 = ""
frontend = "/local/domain/0/frontend/vtpm/2/0"
frontend-id = "0" ('0', frontend is running in Domain-0)
[...]
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()
[...]
--Changes in v3:
-Move xen_stubdom_vtpm.c to xen_vtpm_frontend.c
-Read Xen vTPM status via XenStore
--Changes in v4:
-Redesign vTPM xenstore architecture for HVM virtual machine.
-Remove unnecessary busy loop.
-Call xen_fe_register(vtpm ...) directly and move some initialzation
chunk in the xen_vtpmdev_ops .init function.
Signed-off-by: Quan Xu <quan.xu@xxxxxxxxx>
---
hw/tpm/Makefile.objs | 1 +
hw/tpm/xen_vtpm_frontend.c | 278 +++++++++++++++++++++++++++++++++++++++++++
hw/xen/xen_frontend.c | 20 ++++
include/hw/xen/xen_backend.h | 5 +
include/hw/xen/xen_common.h | 6 +
xen-hvm.c | 5 +
6 files changed, 315 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..4ef0a26
--- /dev/null
+++ b/hw/tpm/xen_vtpm_frontend.c
@@ -0,0 +1,278 @@
+/*
+ * 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"
+
+#define XS_STUBDOM_VTPM_ENABLE "1"
+
+enum tpmif_state {
+ TPMIF_STATE_IDLE, /* no contents / vTPM idle / cancel complete */
+ TPMIF_STATE_SUBMIT, /* request ready / vTPM working */
+ TPMIF_STATE_FINISH, /* response ready / vTPM idle */
+ TPMIF_STATE_CANCEL, /* cancel requested / vTPM working */
+};
+
+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 {
+ uint32_t length; /* request/response length in bytes */
+
+ uint8_t state; /* enum tpmif_state */
+ uint8_t locality; /* for the current request */
+ uint8_t pad; /* should be zero */
+
+ uint8_t nr_extra_pages; /* extra pages for long packets; may be zero */
+ uint32_t extra_pages[0]; /* grant IDs; length is actually nr_extra_pages */
Can you at least mention here that beyond the extra_pages entries is the
actual request/response?
+};
+
+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, size_t *count)
+{
I think you should pass the size of the buf here as well.
+ struct xen_vtpm_dev *vtpmdev = container_of(xendev, struct xen_vtpm_dev,
+ xendev);
+ struct tpmif_shared_page *shr = vtpmdev->shr;
+ unsigned int offset;
+
+ if (shr->state == TPMIF_STATE_IDLE) {
+ return -ECANCELED;
+ }
+
+ offset = sizeof(*shr) + 4*shr->nr_extra_pages;
Replace the '4' with sizeof(uint32_t), if this is what it stands for. Or
better sizeof(shr->extra_pages[0]).
+ memcpy(buf, offset + (uint8_t *)shr, shr->length);
Buf is large enough? I think you should have the buf_size here and
ensure you don't overwrite memory.
+ *count = shr->length;
+
+ return 0;
+}
+
+int vtpm_send(struct XenDevice *xendev, uint8_t* buf, 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 = sizeof(*shr) + 4*shr->nr_extra_pages;
Same comment here.
+
+ while (vtpm_status(vtpmdev) != VTPM_STATUS_IDLE) {
+ vtpm_aio_wait(vtpm_aio_ctx);
+ }
+
+ memcpy(offset + (uint8_t *)shr, buf, count);
Target is always large enough? Introduce a check.
+ shr->length = count;
+ barrier();
+ shr->state = TPMIF_STATE_SUBMIT;
+ xen_wmb();
+ xen_be_send_notify(&vtpmdev->xendev);
+
+ while (vtpm_status(vtpmdev) != VTPM_STATUS_IDLE) {
+ vtpm_aio_wait(vtpm_aio_ctx);
+ }
+
+ return count;
+}
+
+static int vtpm_initialise(struct XenDevice *xendev)
+{
+ struct xen_vtpm_dev *vtpmdev = container_of(xendev, struct xen_vtpm_dev,
+ xendev);
+ xs_transaction_t xbt = XBT_NULL;
+ unsigned int ring_ref;
+
+ vtpmdev->xendev.fe = xenstore_read_be_str(&vtpmdev->xendev, "frontend");
+ if (vtpmdev->xendev.fe == NULL) {
+ return -1;
+ }
+
+ /* Get backend domid */
+ if (xenstore_read_fe_int(&vtpmdev->xendev, "backend-id",
+ &vtpmdev->bedomid)) {
+ return -1;
+ }
+
+ /* Alloc share page */
shared->shared
+ vtpmdev->shr = xc_gntshr_share_pages(vtpmdev->xen_xcs, vtpmdev->bedomid, 1,
+ &ring_ref, PROT_READ|PROT_WRITE);
+ vtpmdev->ring_ref = ring_ref;
+ if (vtpmdev->shr == NULL) {
+ return -1;
+ }
+
+ /* Create event channel */
+ if (xen_fe_alloc_unbound(&vtpmdev->xendev, 0, vtpmdev->bedomid)) {
+ xc_gntshr_munmap(vtpmdev->xen_xcs, vtpmdev->shr, 1);
+ return -1;
+ }
+
+ xc_evtchn_unmask(vtpmdev->xendev.evtchndev,
+ vtpmdev->xendev.local_port);
+
+again:
+ xbt = xs_transaction_start(xenstore);
+ if (xbt == XBT_NULL) {
+ goto abort_transaction;
+ }
+
+ if (xenstore_write_int(vtpmdev->xendev.fe, "ring-ref",
+ vtpmdev->ring_ref)) {
+ goto abort_transaction;
+ }
+
+ if (xenstore_write_int(vtpmdev->xendev.fe, "event-channel",
+ vtpmdev->xendev.local_port)) {
+ goto abort_transaction;
+ }
+
+ /* Publish protocol v2 feature */
+ if (xenstore_write_int(vtpmdev->xendev.fe, "feature-protocol-v2", 1)) {
+ goto abort_transaction;
+ }
+
+ if (!xs_transaction_end(xenstore, xbt, 0)) {
+ if (errno == EAGAIN) {
+ goto again;
+ }
+ }
+
+ return 0;
+
+abort_transaction:
+ xc_gntshr_munmap(vtpmdev->xen_xcs, vtpmdev->shr, 1);
+ xs_transaction_end(xenstore, xbt, 1);
+ return -1;
+}
+
+static int vtpm_free(struct XenDevice *xendev)
+{
+ struct xen_vtpm_dev *vtpmdev = container_of(xendev, struct xen_vtpm_dev,
+ xendev);
add empty line here
+ aio_poll(vtpm_aio_ctx, false);
+ qemu_bh_delete(vtpmdev->sr_bh);
+ if (vtpmdev->shr) {
+ xc_gntshr_munmap(vtpmdev->xen_xcs, vtpmdev->shr, 1);
+ }
+ xc_interface_close(vtpmdev->xen_xcs);
+ return 0;
+}
+
+static int vtpm_init(struct XenDevice *xendev)
+{
+ char path[XEN_BUFSIZE];
+ char *value;
+ unsigned int stubdom_vtpm = 0;
+
+ snprintf(path, sizeof(path), "/local/domain/%d/platform/acpi_stubdom_vtpm",
+ xen_domid);
+ value = xs_read(xenstore, 0, path, &stubdom_vtpm);
+ if (stubdom_vtpm <= 0 || strcmp(value, XS_STUBDOM_VTPM_ENABLE)) {
+ free(value);
+ return -1;
+ }
+ free(value);
+ return 0;
+}
+
+static void vtpm_alloc(struct XenDevice *xendev)
+{
+ struct xen_vtpm_dev *vtpmdev = container_of(xendev, struct xen_vtpm_dev,
+ xendev);
+
+ vtpm_aio_ctx = aio_context_new(NULL);
+ if (vtpm_aio_ctx == NULL) {
+ return;
+ }
+ vtpmdev->sr_bh = aio_bh_new(vtpm_aio_ctx, sr_bh_handler, vtpmdev);
+ qemu_bh_schedule(vtpmdev->sr_bh);
+ vtpmdev->xen_xcs = xen_xc_gntshr_open(0, 0);
+}
+
+static void vtpm_event(struct XenDevice *xendev)
+{
+ struct xen_vtpm_dev *vtpmdev = container_of(xendev, struct xen_vtpm_dev,
+ xendev);
+
+ qemu_bh_schedule(vtpmdev->sr_bh);
+}
+
+struct XenDevOps xen_vtpmdev_ops = {
+ .size = sizeof(struct xen_vtpm_dev),
+ .flags = DEVOPS_FLAG_IGNORE_STATE |
+ DEVOPS_FLAG_FE,
+ .event = vtpm_event,
+ .free = vtpm_free,
+ .init = vtpm_init,
+ .alloc = vtpm_alloc,
+ .initialise = vtpm_initialise,
+ .backend_changed = vtpm_backend_changed,
+};
diff --git a/hw/xen/xen_frontend.c b/hw/xen/xen_frontend.c
index 55af45a..1ca7342 100644
--- a/hw/xen/xen_frontend.c
+++ b/hw/xen/xen_frontend.c
@@ -60,6 +60,26 @@ static void xen_fe_evtchn_event(void *opaque)
/* ------------------------------------------------------------- */
+void vtpm_backend_changed(struct XenDevice *xendev, const char *node)
+{
+ int be_state;
+
+ if (strcmp(node, "state") == 0) {
+ xenstore_read_be_int(xendev, node, &be_state);
+ switch (be_state) {
+ case XenbusStateConnected:
+ /* TODO */
+ break;
+ case XenbusStateClosing:
+ case XenbusStateClosed:
+ xenbus_switch_state(xendev, XenbusStateClosing);
+ break;
+ default:
+ break;
+ }
+ }
+}
+
int xen_fe_alloc_unbound(struct XenDevice *xendev, int dom, int remote_dom)
{
xendev->local_port = xc_evtchn_bind_unbound_port(xendev->evtchndev,
diff --git a/include/hw/xen/xen_backend.h b/include/hw/xen/xen_backend.h
index bb0b303..b959413 100644
--- a/include/hw/xen/xen_backend.h
+++ b/include/hw/xen/xen_backend.h
@@ -110,6 +110,11 @@ int xen_fe_register(const char *type, struct XenDevOps
*ops);
int xen_fe_alloc_unbound(struct XenDevice *xendev, int dom, int remote_dom);
int xenbus_switch_state(struct XenDevice *xendev, enum xenbus_state xbus);
+/* Xen vtpm */
+int vtpm_send(struct XenDevice *xendev, uint8_t* buf, size_t count);
+int vtpm_recv(struct XenDevice *xendev, uint8_t* buf, size_t *count);
+void vtpm_backend_changed(struct XenDevice *xendev, const char *node);
+
/* actual backend drivers */
extern struct XenDevOps xen_console_ops; /* xen_console.c */
extern struct XenDevOps xen_kbdmouse_ops; /* xen_framebuffer.c */
diff --git a/include/hw/xen/xen_common.h b/include/hw/xen/xen_common.h
index 07731b9..e81d230 100644
--- a/include/hw/xen/xen_common.h
+++ b/include/hw/xen/xen_common.h
@@ -130,6 +130,12 @@ static inline XenXC xen_xc_interface_open(void *logger,
void *dombuild_logger,
return xc_interface_open(logger, dombuild_logger, open_flags);
}
+static inline xc_gntshr *xen_xc_gntshr_open(void *logger,
+ unsigned int open_flags)
+{
+ return xc_gntshr_open(logger, open_flags);
+}
+
/* FIXME There is now way to have the xen fd */
static inline int xc_fd(xc_interface *xen_xc)
{
diff --git a/xen-hvm.c b/xen-hvm.c
index 05e522c..e21dfee 100644
--- a/xen-hvm.c
+++ b/xen-hvm.c
@@ -1071,6 +1071,11 @@ int xen_hvm_init(ram_addr_t *below_4g_mem_size,
ram_addr_t *above_4g_mem_size,
fprintf(stderr, "%s: xen backend core setup failed\n", __FUNCTION__);
return -1;
}
+
+#ifdef CONFIG_TPM_XENSTUBDOMS
+ xen_fe_register("vtpm", &xen_vtpmdev_ops);
+#endif
+
xen_be_register("console", &xen_console_ops);
xen_be_register("vkbd", &xen_kbdmouse_ops);
xen_be_register("qdisk", &xen_blkdev_ops);
Stefan
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