Re: [QEMU][PATCH v2 10/11] hw/arm: introduce xenpv machine

[Vikram Garhwal <vikram.garhwal@amd.com>]

Hi Alex,

On 12/2/22 6:52 AM, Alex Bennée wrote:
> Vikram Garhwal <vikram.garhwal@amd.com> writes:
>
>> Add a new machine xenpv which creates a IOREQ server to register/connect with
>> Xen Hypervisor.
>>
>> Optional: When CONFIG_TPM is enabled, it also creates a tpm-tis-device, adds a
>> TPM emulator and connects to swtpm running on host machine via chardev socket
>> and support TPM functionalities for a guest domain.
>>
>> Extra command line for aarch64 xenpv QEMU to connect to swtpm:
>>      -chardev socket,id=chrtpm,path=/tmp/myvtpm2/swtpm-sock \
>>      -tpmdev emulator,id=tpm0,chardev=chrtpm \
>>
>> swtpm implements a TPM software emulator(TPM 1.2 & TPM 2) built on libtpms and
>> provides access to TPM functionality over socket, chardev and CUSE interface.
>> Github repo: https://github.com/stefanberger/swtpm
>> Example for starting swtpm on host machine:
>>      mkdir /tmp/vtpm2
>>      swtpm socket --tpmstate dir=/tmp/vtpm2 \
>>      --ctrl type=unixio,path=/tmp/vtpm2/swtpm-sock &
> <snip>
>> +
>> +static void xen_enable_tpm(void)
>> +{
>> +/* qemu_find_tpm_be is only available when CONFIG_TPM is enabled. */
>> +#ifdef CONFIG_TPM
>> +    Error *errp = NULL;
>> +    DeviceState *dev;
>> +    SysBusDevice *busdev;
>> +
>> +    TPMBackend *be = qemu_find_tpm_be("tpm0");
>> +    if (be == NULL) {
>> +        DPRINTF("Couldn't fine the backend for tpm0\n");
>> +        return;
>> +    }
>> +    dev = qdev_new(TYPE_TPM_TIS_SYSBUS);
>> +    object_property_set_link(OBJECT(dev), "tpmdev", OBJECT(be), &errp);
>> +    object_property_set_str(OBJECT(dev), "tpmdev", be->id, &errp);
>> +    busdev = SYS_BUS_DEVICE(dev);
>> +    sysbus_realize_and_unref(busdev, &error_fatal);
>> +    sysbus_mmio_map(busdev, 0, GUEST_TPM_BASE);
> Still fails on my aarch64 Debian machine:
>
>    FAILED: libqemu-aarch64-softmmu.fa.p/hw_arm_xen_arm.c.o
>    cc -Ilibqemu-aarch64-softmmu.fa.p -I. -I../.. -Itarget/arm -I../../target/arm -Iqapi -Itrace -Iui -Iui/shader -I/usr/include/pixman-1 -I/usr/local/include -I/usr/include/capstone -I/usr/include/spice-server -I/usr/include/spice-1 -I/usr/include/glib-2.0 -I/usr/lib/aarch64-linux-gnu/glib-2.0/include -fdiagnostics-color=auto -Wall -Winvalid-pch -Werror -std=gnu11 -O2 -g -isystem /home/alex/lsrc/qemu.git/linux-headers -isystem linux-headers -iquote . -iquote /home/alex/lsrc/qemu.git -iquote /home/alex/lsrc/qemu.git/include -iquote /home/alex/lsrc/qemu.git/tcg/aarch64 -pthread -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -Wstrict-prototypes -Wredundant-decls -Wundef -Wwrite-strings -Wmissing-prototypes -fno-strict-aliasing -fno-common -fwrapv -Wold-style-declaration -Wold-style-definition -Wtype-limits -Wformat-security -Wformat-y2k -Winit-self -Wignored-qualifiers -Wempty-body -Wnested-externs -Wendif-labels -Wexpansion-to-defined -Wimplicit-fallthrough=2 -Wno-missing-include-dirs -Wno-shift-negative-value -Wno-psabi -fstack-protector-strong -fPIE -isystem../../linux-headers -isystemlinux-headers -DNEED_CPU_H '-DCONFIG_TARGET="aarch64-softmmu-config-target.h"' '-DCONFIG_DEVICES="aarch64-softmmu-config-devices.h"' -MD -MQ libqemu-aarch64-softmmu.fa.p/hw_arm_xen_arm.c.o -MF libqemu-aarch64-softmmu.fa.p/hw_arm_xen_arm.c.o.d -o libqemu-aarch64-softmmu.fa.p/hw_arm_xen_arm.c.o -c ../../hw/arm/xen_arm.c
>    ../../hw/arm/xen_arm.c: In function ‘xen_enable_tpm’:
>    ../../hw/arm/xen_arm.c:126:32: error: ‘GUEST_TPM_BASE’ undeclared (first use in this function); did you mean ‘GUEST_RAM_BASE’?
>      126 |     sysbus_mmio_map(busdev, 0, GUEST_TPM_BASE);
>          |                                ^~~~~~~~~~~~~~
>          |                                GUEST_RAM_BASE
>    ../../hw/arm/xen_arm.c:126:32: note: each undeclared identifier is reported only once for each function it appears in
>    [2082/3246] Compiling C object libqemu-aarch64-softmmu.fa.p/hw_xen_xen-mapcache.c.o
>    [2083/3246] Compiling C object libqemu-aarch64-softmmu.fa.p/hw_xen_xen-hvm-common.c.o
>    ninja: build stopped: subcommand failed.
>    make: *** [Makefile:165: run-ninja] Error 1
>
Do you know what Xen version your build env has?

Another way to fix this(as Julien suggested) is by setting this 
GUEST_TPM_BASE value via a property or something and user can set it via 
command line.

@sstabellini@kernel.org, do you think of any other fix?
>> +
>> +    DPRINTF("Connected tpmdev at address 0x%lx\n", GUEST_TPM_BASE);
>> +#endif
>> +}
> If there is a minimum required version for TPM then it needs to be
> picked up by configure.
>