arm64/boot: Disable trapping of PMZR_EL0 writes to EL2grafted

__init_el2_fgt2() writes one mask to both HDFGRTR2_EL2 and HDFGWTR2_EL2.
PMZR_EL0 is write-only, so its trap bit, nPMZR_EL0, exists only in
HDFGWTR2_EL2 and is therefore never set: a PMZR_EL0 write from the host
traps to EL2, where the nVHE hypervisor has no handler and BUG()s. The
kernel never writes PMZR_EL0, but kernel.perf_user_access=1 has the PMU
driver set PMUSERENR_EL0.UEN for a task with a user-read event, so a
write from EL0 reaches the trap and takes the host down without a panic
message.

Accumulate the HDFGWTR2_EL2 bits separately, as __init_el2_fgt() already
does for HDFGWTR_EL2, and set nPMZR_EL0 with the other FEAT_PMUv3p9
bits.

Fixes: 858c7bfcb35e1 ("arm64/boot: Enable EL2 requirements for FEAT_PMUv3p9")
Cc: stable@vger.kernel.org
Signed-off-by: Fuad Tabba <fuad.tabba@linux.dev>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Oliver Upton <oupton@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>

1 files changed, 85 insertions, 0 deletions

diff --git a/drivers/firmware/google/Kconfig b/drivers/firmware/google/Kconfig
new file mode 100644
index 000000000..b78c644fa
--- /dev/null
+++ b/drivers/firmware/google/Kconfig
@@ -0,0 +1,85 @@
+# SPDX-License-Identifier: GPL-2.0-only
+menuconfig GOOGLE_FIRMWARE
+	bool "Google Firmware Drivers"
+	default n
+	help
+	  These firmware drivers are used by Google servers,
+	  Chromebooks and other devices using coreboot firmware.
+	  If in doubt, say "N".
+
+if GOOGLE_FIRMWARE
+
+config GOOGLE_SMI
+	tristate "SMI interface for Google platforms"
+	depends on X86 && ACPI && DMI
+	help
+	  Say Y here if you want to enable SMI callbacks for Google
+	  platforms.  This provides an interface for writing to and
+	  clearing the event log.  If CONFIG_EFI is also enabled this
+	  driver provides an interface for reading and writing NVRAM
+	  variables.
+
+config GOOGLE_CBMEM
+	tristate "CBMEM entries in sysfs"
+	depends on GOOGLE_COREBOOT_TABLE
+	help
+	  CBMEM is a downwards-growing memory region created by the
+	  Coreboot BIOS containing tagged data structures from the
+	  BIOS.  These data structures expose things like the verified
+	  boot firmware variables, flash layout, firmware event log,
+	  and more.
+
+	  This option enables the cbmem module, which causes the
+	  kernel to search for Coreboot CBMEM entries, and expose the
+	  memory for each entry in sysfs under
+	  /sys/bus/coreboot/devices/cbmem-<id>.
+
+config GOOGLE_COREBOOT_TABLE
+	tristate "Coreboot Table Access"
+	depends on HAS_IOMEM && (ACPI || OF)
+	help
+	  This option enables the coreboot_table module, which provides other
+	  firmware modules access to the coreboot table. The coreboot table
+	  pointer is accessed through the ACPI "GOOGCB00" object or the
+	  device tree node /firmware/coreboot.
+	  If unsure say N.
+
+config GOOGLE_MEMCONSOLE
+	tristate
+	depends on GOOGLE_MEMCONSOLE_X86_LEGACY || GOOGLE_MEMCONSOLE_COREBOOT
+
+config GOOGLE_MEMCONSOLE_X86_LEGACY
+	tristate "Firmware Memory Console - X86 Legacy support"
+	depends on X86 && ACPI && DMI
+	select GOOGLE_MEMCONSOLE
+	help
+	  This option enables the kernel to search for a firmware log in
+	  the EBDA on Google servers.  If found, this log is exported to
+	  userland in the file /sys/firmware/log.
+
+config GOOGLE_FRAMEBUFFER_COREBOOT
+	tristate "Coreboot Framebuffer"
+	depends on GOOGLE_COREBOOT_TABLE
+	help
+	  This option enables the kernel to search for a framebuffer in
+	  the coreboot table.  If found, it is registered with a platform
+	  device of type coreboot-framebuffer. Using the old device of
+	  type simple-framebuffer is deprecated.
+
+config GOOGLE_MEMCONSOLE_COREBOOT
+	tristate "Firmware Memory Console"
+	depends on GOOGLE_COREBOOT_TABLE
+	select GOOGLE_MEMCONSOLE
+	help
+	  This option enables the kernel to search for a firmware log in
+	  the coreboot table.  If found, this log is exported to userland
+	  in the file /sys/firmware/log.
+
+config GOOGLE_VPD
+	tristate "Vital Product Data"
+	depends on GOOGLE_COREBOOT_TABLE
+	help
+	  This option enables the kernel to expose the content of Google VPD
+	  under /sys/firmware/vpd.
+
+endif # GOOGLE_FIRMWARE