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

[Vikram Garhwal <vikram.garhwal@xxxxxxx>]

Hi Alex,

On 12/2/22 6:52 AM, Alex Bennée wrote:
> Vikram Garhwal <vikram.garhwal@xxxxxxx> 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@xxxxxxxxxx, 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.