diff options
author | Alex Bennée <alex.bennee@linaro.org> | 2022-01-05 13:49:56 +0000 |
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committer | Alex Bennée <alex.bennee@linaro.org> | 2022-01-18 16:42:42 +0000 |
commit | 33973e1e1f88b7588fe9629645e279ff2c6ca1c4 (patch) | |
tree | bddb1128cb4c4346513d2744a5fc413b02bce852 /hw/arm | |
parent | 7bef20d72985c5da4082d198ad175715272cd50c (diff) | |
download | qemu-33973e1e1f88b7588fe9629645e279ff2c6ca1c4.zip qemu-33973e1e1f88b7588fe9629645e279ff2c6ca1c4.tar.gz qemu-33973e1e1f88b7588fe9629645e279ff2c6ca1c4.tar.bz2 |
hw/arm: add control knob to disable kaslr_seed via DTB
Generally a guest needs an external source of randomness to properly
enable things like address space randomisation. However in a trusted
boot environment where the firmware will cryptographically verify
components having random data in the DTB will cause verification to
fail. Add a control knob so we can prevent this being added to the
system DTB.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Acked-by: Jerome Forissier <jerome@forissier.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Message-Id: <20220105135009.1584676-22-alex.bennee@linaro.org>
Diffstat (limited to 'hw/arm')
-rw-r--r-- | hw/arm/virt.c | 32 |
1 files changed, 30 insertions, 2 deletions
diff --git a/hw/arm/virt.c b/hw/arm/virt.c index b45b52c..84c2444 100644 --- a/hw/arm/virt.c +++ b/hw/arm/virt.c @@ -247,11 +247,15 @@ static void create_fdt(VirtMachineState *vms) /* /chosen must exist for load_dtb to fill in necessary properties later */ qemu_fdt_add_subnode(fdt, "/chosen"); - create_kaslr_seed(ms, "/chosen"); + if (vms->dtb_kaslr_seed) { + create_kaslr_seed(ms, "/chosen"); + } if (vms->secure) { qemu_fdt_add_subnode(fdt, "/secure-chosen"); - create_kaslr_seed(ms, "/secure-chosen"); + if (vms->dtb_kaslr_seed) { + create_kaslr_seed(ms, "/secure-chosen"); + } } /* Clock node, for the benefit of the UART. The kernel device tree @@ -2235,6 +2239,20 @@ static void virt_set_its(Object *obj, bool value, Error **errp) vms->its = value; } +static bool virt_get_dtb_kaslr_seed(Object *obj, Error **errp) +{ + VirtMachineState *vms = VIRT_MACHINE(obj); + + return vms->dtb_kaslr_seed; +} + +static void virt_set_dtb_kaslr_seed(Object *obj, bool value, Error **errp) +{ + VirtMachineState *vms = VIRT_MACHINE(obj); + + vms->dtb_kaslr_seed = value; +} + static char *virt_get_oem_id(Object *obj, Error **errp) { VirtMachineState *vms = VIRT_MACHINE(obj); @@ -2764,6 +2782,13 @@ static void virt_machine_class_init(ObjectClass *oc, void *data) "Set on/off to enable/disable " "ITS instantiation"); + object_class_property_add_bool(oc, "dtb-kaslr-seed", + virt_get_dtb_kaslr_seed, + virt_set_dtb_kaslr_seed); + object_class_property_set_description(oc, "dtb-kaslr-seed", + "Set off to disable passing of kaslr-seed " + "dtb node to guest"); + object_class_property_add_str(oc, "x-oem-id", virt_get_oem_id, virt_set_oem_id); @@ -2828,6 +2853,9 @@ static void virt_instance_init(Object *obj) /* MTE is disabled by default. */ vms->mte = false; + /* Supply a kaslr-seed by default */ + vms->dtb_kaslr_seed = true; + vms->irqmap = a15irqmap; virt_flash_create(vms); |