Re: [Qemu-devel] [PATCH v6 3/6] Qemu-Xen-vTPM: Xen frontend driver infrastructure

[Stefan Berger <stefanb@linux.vnet.ibm.com>]

On 05/04/2015 10:41 PM, Xu, Quan wrote:
>
>> -----Original Message-----
>> From: Stefan Berger [mailto:stefanb@linux.vnet.ibm.com]
>> Sent: Monday, May 04, 2015 11:36 PM
>> To: Xu, Quan; stefano.stabellini@eu.citrix.com; eblake@redhat.com
>> Cc: qemu-devel@nongnu.org; wei.liu2@citrix.com; dgdegra@tycho.nsa.gov;
>> xen-devel@lists.xen.org
>> Subject: Re: [PATCH v6 3/6] Qemu-Xen-vTPM: Xen frontend driver infrastructure
>>
>> On 05/04/2015 03:22 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@intel.com>
>>>
>>> --Changes in v6:
>>>    -Replace buf_size with PAGE_SIZE and use length rather than
>>>     shr->length.
>>> ---
>>>    hw/tpm/Makefile.objs         |   1 +
>>>    hw/tpm/xen_vtpm_frontend.c   | 315
>> +++++++++++++++++++++++++++++++++++++++++++
>>>    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, 352 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..d6e7cc6
>>> --- /dev/null
>>> +++ b/hw/tpm/xen_vtpm_frontend.c
>>> @@ -0,0 +1,315 @@
>>> +/*
>>> + * Connect to Xen vTPM stubdom domain
>>> + *
>>> + *  Copyright (c) 2015 Intel Corporation
>>> + *  Authors:
>>> + *    Quan Xu <quan.xu@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"
>>> +
>>> +#ifndef XS_STUBDOM_VTPM_ENABLE
>>> +#define XS_STUBDOM_VTPM_ENABLE    "1"
>>> +#endif
>>> +
>>> +#ifndef PAGE_SIZE
>>> +#define PAGE_SIZE      4096
>>> +#endif
>> You should be able to use TARGET_PAGE_SIZE from exec/cpu-all.h I think.
>>
>> With this change: Reviewed-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
>>
>
> Stefan, thanks.
> I will use TARGET_PAGE_SIZE from exec/cpu-all.h in next version.
> Could I redefine PAGE_SIZE as kvm-all.c?
> +#define PAGE_SIZE TARGET_PAGE_SIZE

I guess it would be ok.

    Stefan