On Tue, 30 Dec 2014, 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]
> ..
> FE.DOMAIN.ID
> device = ""
> vtpm = ""
> 0 = ""
> backend = "/local/domain/{BE.DOMAIN.ID}/backend/vtpm/{FE.DOMAIN.ID}/0"
> backend-id = "BE.DOMAIN.ID"
> state = "1"
> handle = "0"
> ..
>
> (QEMU) xen_vtpmdev_ops is initialized with the following process:
> xen_hvm_init()
> [...]
> -->xen_fe_register("vtpm", ...)
> -->xenstore_fe_scan()
> -->xen_fe_get_xendev()
> --> XenDevOps.alloc()
> -->xen_fe_check()
> --> XenDevOps.init()
> --> XenDevOps.initialise()
> --> XenDevOps.connected()
> -->xs_watch()
> [...]
>
> --Changes in v3:
> -Move xen_stubdom_vtpm.c to xen_vtpm_frontend.c
> -Read Xen vTPM status via XenStore
>
> Signed-off-by: Quan Xu <quan...@intel.com>
> ---
> hw/tpm/Makefile.objs | 1 +
> hw/tpm/xen_vtpm_frontend.c | 264
> +++++++++++++++++++++++++++++++++++++++++++
> hw/xen/xen_backend.c | 34 ++++++
> include/hw/xen/xen_backend.h | 9 +-
> include/hw/xen/xen_common.h | 6 +
> xen-hvm.c | 16 +++
> 6 files changed, 328 insertions(+), 2 deletions(-)
> 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..00cc888
> --- /dev/null
> +++ b/hw/tpm/xen_vtpm_frontend.c
> @@ -0,0 +1,264 @@
> +/*
> + * Connect to Xen vTPM stubdom domain
> + *
> + * Copyright (c) 2014 Intel Corporation
> + * Authors:
> + * Quan Xu <quan...@intel.com>
> + *
> + * 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"
> +
> +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
> */
> +};
> +
> +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)
> +{
> + 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;
> + }
> +
> + while (vtpm_status(vtpmdev) != VTPM_STATUS_IDLE) {
> + vtpm_aio_wait(vtpm_aio_ctx);
> + }
> +
> + offset = sizeof(*shr) + 4*shr->nr_extra_pages;
> + memcpy(buf, offset + (uint8_t *)shr, shr->length);
> + *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;
> +
> + while (vtpm_status(vtpmdev) != VTPM_STATUS_IDLE) {
> + vtpm_aio_wait(vtpm_aio_ctx);
> + }
> +
> + memcpy(offset + (uint8_t *)shr, buf, count);
> + 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*/
> + 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_be_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;
> + }
> + }
> + /* Tell vtpm backend that we are ready */
> + xenbus_switch_state(&vtpmdev->xendev, XenbusStateInitialised);
> +
> + 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);
> + 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 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,
> + .alloc = vtpm_alloc,
> + .initialise = vtpm_initialise,
> + .backend_changed = vtpm_backend_changed,
> +};
> diff --git a/hw/xen/xen_backend.c b/hw/xen/xen_backend.c
> index ad6e324..377a9c8 100644
> --- a/hw/xen/xen_backend.c
> +++ b/hw/xen/xen_backend.c
> @@ -741,6 +741,20 @@ int xen_be_register(const char *type, struct XenDevOps
> *ops)
> return xenstore_scan(type, xen_domid, ops);
> }
>
> +int xen_be_alloc_unbound(struct XenDevice *xendev, int dom, int remote_dom)
> +{
> + xendev->local_port = xc_evtchn_bind_unbound_port(xendev->evtchndev,
> + remote_dom);
> + if (xendev->local_port == -1) {
> + xen_be_printf(xendev, 0, "xc_evtchn_alloc_unbound failed\n");
> + return -1;
> + }
> + xen_be_printf(xendev, 2, "bind evtchn port %d\n", xendev->local_port);
> + qemu_set_fd_handler(xc_evtchn_fd(xendev->evtchndev),
> + xen_be_evtchn_event, NULL, xendev);
> + return 0;
> +}
Why are you calling this xen_be_alloc_unbound? Shouldn't it be called
xen_fe_alloc_unbound and be in xen_frontend.c, given that is called only
by a frontend?
> int xen_be_bind_evtchn(struct XenDevice *xendev)
> {
> if (xendev->local_port != -1) {
> @@ -813,6 +827,26 @@ void xen_be_printf(struct XenDevice *xendev, int
> msg_level, const char *fmt, ...
> qemu_log_flush();
> }
>
> +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;
> + }
> + }
> +}
This should be written as a generic fe function in xen_frontend.c
> void xen_qtail_insert_xendev(struct XenDevice *xendev)
> {
> QTAILQ_INSERT_TAIL(&xendevs, xendev, next);
> diff --git a/include/hw/xen/xen_backend.h b/include/hw/xen/xen_backend.h
> index 06e202f..d07ae36 100644
> --- a/include/hw/xen/xen_backend.h
> +++ b/include/hw/xen/xen_backend.h
> @@ -102,8 +102,12 @@ char *xenstore_fe_read_be_str(const char *type, int dom,
> int dev);
> int xenbus_switch_state(struct XenDevice *xendev, enum xenbus_state xbus);
> struct XenDevice *xen_fe_get_xendev(const char *type, int dom, int dev,
> struct XenDevOps *ops);
> -void xenstore_fe_update(char *watch, char *type, int dom,
> - struct XenDevOps *ops);
> +void xenstore_fe_update(char *watch, char *type, int dom, struct XenDevOps
> *ops);
> +
> +/*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 */
> @@ -111,6 +115,7 @@ extern struct XenDevOps xen_kbdmouse_ops; /*
> xen_framebuffer.c */
> extern struct XenDevOps xen_framebuffer_ops; /* xen_framebuffer.c */
> extern struct XenDevOps xen_blkdev_ops; /* xen_disk.c */
> extern struct XenDevOps xen_netdev_ops; /* xen_nic.c */
> +extern struct XenDevOps xen_vtpmdev_ops; /* xen_vtpm_frontend.c*/
>
> void xen_init_display(int domid);
>
> diff --git a/include/hw/xen/xen_common.h b/include/hw/xen/xen_common.h
> index 07731b9..2e9bb62 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..5b93cd4 100644
> --- a/xen-hvm.c
> +++ b/xen-hvm.c
> @@ -986,6 +986,12 @@ int xen_hvm_init(ram_addr_t *below_4g_mem_size,
> ram_addr_t *above_4g_mem_size,
> int i, rc;
> unsigned long ioreq_pfn;
> unsigned long bufioreq_evtchn;
> +
> +#ifdef CONFIG_TPM_XENSTUBDOMS
> + char path[XEN_BUFSIZE];
> + unsigned int stubdom_vtpm = 0;
> +#endif
> +
> XenIOState *state;
>
> state = g_malloc0(sizeof (XenIOState));
> @@ -1071,6 +1077,16 @@ 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
> + snprintf(path, sizeof(path),
> "/local/domain/%d/platform/acpi_stubdom_vtpm",
> + xen_domid);
> + xs_read(state->xenstore, 0, path, &stubdom_vtpm);
> + if (stubdom_vtpm) {
> + xen_fe_register("vtpm", &xen_vtpmdev_ops);
> + }
> +#endif
I think you should always call xen_fe_register(vtpm ...) and move this
chunk in the xen_vtpmdev_ops .init function.
> xen_be_register("console", &xen_console_ops);
> xen_be_register("vkbd", &xen_kbdmouse_ops);
> xen_be_register("qdisk", &xen_blkdev_ops);
> --
> 1.8.3.2
>
