Re: [PATCHv8 3/3] arm-virt: add secure pl061 for reset/power down

[Peter Maydell]

On Fri, 22 Jan 2021 at 08:29, Andrew Jones <drjones@redhat.com> wrote:
>
> On Wed, Jan 20, 2021 at 12:27:48PM +0300, Maxim Uvarov wrote:
> > Add secure pl061 for reset/power down machine from
> > the secure world (Arm Trusted Firmware). Connect it
> > with gpio-pwr driver.
> >
> > Signed-off-by: Maxim Uvarov <maxim.uvarov@linaro.org>
> > ---
> >  hw/arm/Kconfig        |  1 +
> >  hw/arm/virt.c         | 47 +++++++++++++++++++++++++++++++++++++++++++
> >  include/hw/arm/virt.h |  2 ++
> >  3 files changed, 50 insertions(+)
> >
> > diff --git a/hw/arm/Kconfig b/hw/arm/Kconfig
> > index 0a242e4c5d..13cc42dcc8 100644
> > --- a/hw/arm/Kconfig
> > +++ b/hw/arm/Kconfig
> > @@ -17,6 +17,7 @@ config ARM_VIRT
> >      select PL011 # UART
> >      select PL031 # RTC
> >      select PL061 # GPIO
> > +    select GPIO_PWR
> >      select PLATFORM_BUS
> >      select SMBIOS
> >      select VIRTIO_MMIO
> > diff --git a/hw/arm/virt.c b/hw/arm/virt.c
> > index c427ce5f81..060a5f492e 100644
> > --- a/hw/arm/virt.c
> > +++ b/hw/arm/virt.c
> > @@ -153,6 +153,7 @@ static const MemMapEntry base_memmap[] = {
> >      [VIRT_ACPI_GED] =           { 0x09080000, ACPI_GED_EVT_SEL_LEN },
> >      [VIRT_NVDIMM_ACPI] =        { 0x09090000, NVDIMM_ACPI_IO_LEN},
> >      [VIRT_PVTIME] =             { 0x090a0000, 0x00010000 },
> > +    [VIRT_SECURE_GPIO] =        { 0x090b0000, 0x00001000 },
> >      [VIRT_MMIO] =               { 0x0a000000, 0x00000200 },
> >      /* ...repeating for a total of NUM_VIRTIO_TRANSPORTS, each of that 
> > size */
> >      [VIRT_PLATFORM_BUS] =       { 0x0c000000, 0x02000000 },
> > @@ -841,6 +842,43 @@ static void create_gpio_keys(const VirtMachineState 
> > *vms,
> >                             "gpios", phandle, 3, 0);
> >  }
> >
> > +#define SECURE_GPIO_POWEROFF 0
> > +#define SECURE_GPIO_REBOOT   1
> > +
> > +static void create_gpio_pwr(const VirtMachineState *vms,
>
> This function is specific to the secure view. I think it should have
> "secure" in its name.
>
> > +                            DeviceState *pl061_dev,
> > +                            uint32_t phandle)
> > +{
> > +    DeviceState *gpio_pwr_dev;
> > +
> > +    /* gpio-pwr */
> > +    gpio_pwr_dev = sysbus_create_simple("gpio-pwr", -1, NULL);
>
> Should this device be in secure memory?

It's not in any memory at all -- -1 as the address argument
to sysbus_create_simple() means "no MMIO regions to map". The
only way it's connected to the rest of the system is via  the
secure-only PL061, so the NS world can't get at it.

(sysbus_create_simple("device", -1, NULL) is equivalent to:
 dev = qdev_new("device");
 sysbus_realize_and_unref(SYSBUS_DEVICE(dev), &error_fatal);
)

thanks
-- PMM