Commit 2c1fb4d5 authored by Andrew Jones's avatar Andrew Jones Committed by Peter Maydell
Browse files

hw/arm/virt-acpi-build: Only expose flash on older machine types 



The flash device is exclusively for the host-controlled firmware, so
we should not expose it to the OS. Exposing it risks the OS messing
with it, which could break firmware runtime services and surprise the
OS when all its changes disappear after reboot.

As firmware needs the device and uses DT, we leave the device exposed
there. It's up to firmware to remove the nodes from DT before sending
it on to the OS. However, there's no need to force firmware to remove
tables from ACPI (which it doesn't know how to do anyway), so we
simply don't add the tables in the first place. But, as we've been
adding the tables for quite some time and don't want to change the
default hardware exposed to versioned machines, then we only stop
exposing the flash device tables for 5.1 and later machine types.

Suggested-by: default avatarArd Biesheuvel <ard.biesheuvel@arm.com>
Suggested-by: default avatarLaszlo Ersek <lersek@redhat.com>
Signed-off-by: default avatarAndrew Jones <drjones@redhat.com>
Reviewed-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Reviewed-by: default avatarEric Auger <eric.auger@redhat.com>
Reviewed-by: default avatarPhilippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: default avatarLaszlo Ersek <lersek@redhat.com>
Message-id: 20200629140938.17566-4-drjones@redhat.com
Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
parent 50824a8c

hw/arm/virt-acpi-build.c

+4 −1
Original line number Diff line number Diff line
@@ -749,6 +749,7 @@ static void build_fadt_rev5(GArray *table_data, BIOSLinker *linker, 
static void

build_dsdt(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)

{

    VirtMachineClass *vmc = VIRT_MACHINE_GET_CLASS(vms);

    Aml *scope, *dsdt;

    MachineState *ms = MACHINE(vms);

    const MemMapEntry *memmap = vms->memmap;
@@ -767,7 +768,9 @@ build_dsdt(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms) 
    acpi_dsdt_add_cpus(scope, vms->smp_cpus);

    acpi_dsdt_add_uart(scope, &memmap[VIRT_UART],

                       (irqmap[VIRT_UART] + ARM_SPI_BASE));

    if (vmc->acpi_expose_flash) {

        acpi_dsdt_add_flash(scope, &memmap[VIRT_FLASH]);

    }

    acpi_dsdt_add_fw_cfg(scope, &memmap[VIRT_FW_CFG]);

    acpi_dsdt_add_virtio(scope, &memmap[VIRT_MMIO],

                    (irqmap[VIRT_MMIO] + ARM_SPI_BASE), NUM_VIRTIO_TRANSPORTS);

hw/arm/virt.c

+3 −0
Original line number Diff line number Diff line
@@ -2510,9 +2510,12 @@ DEFINE_VIRT_MACHINE_AS_LATEST(5, 1) 


static void virt_machine_5_0_options(MachineClass *mc)

{

    VirtMachineClass *vmc = VIRT_MACHINE_CLASS(OBJECT_CLASS(mc));



    virt_machine_5_1_options(mc);

    compat_props_add(mc->compat_props, hw_compat_5_0, hw_compat_5_0_len);

    mc->numa_mem_supported = true;

    vmc->acpi_expose_flash = true;

}

DEFINE_VIRT_MACHINE(5, 0)

include/hw/arm/virt.h

+1 −0
Original line number Diff line number Diff line
@@ -125,6 +125,7 @@ typedef struct { 
    bool no_highmem_ecam;

    bool no_ged;   /* Machines < 4.2 has no support for ACPI GED device */

    bool kvm_no_adjvtime;

    bool acpi_expose_flash;

} VirtMachineClass;



typedef struct {