Catalin Marinas 6aebd2da8d KVM: arm64: Avoid setting the upper 32 bits of TCR_EL2 and CPTR_EL2 to 1 ...

commit 1f80d15020 upstream.

Having a signed (1 << 31) constant for TCR_EL2_RES1 and CPTR_EL2_TCPAC
causes the upper 32-bit to be set to 1 when assigning them to a 64-bit
variable. Bit 32 in TCR_EL2 is no longer RES0 in ARMv8.7: with FEAT_LPA2
it changes the meaning of bits 49:48 and 9:8 in the stage 1 EL2 page
table entries. As a result of the sign-extension, a non-VHE kernel can
no longer boot on a model with ARMv8.7 enabled.

CPTR_EL2 still has the top 32 bits RES0 but we should preempt any future
problems

Make these top bit constants unsigned as per commit df655b75c4
("arm64: KVM: Avoid setting the upper 32 bits of VTCR_EL2 to 1").

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Chris January <Chris.January@arm.com>
Cc: <stable@vger.kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211125152014.2806582-1-catalin.marinas@arm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2021-12-08 09:04:44 +01:00

..

asm

KVM: arm64: Avoid setting the upper 32 bits of TCR_EL2 and CPTR_EL2 to 1

2021-12-08 09:04:44 +01:00

uapi/asm

arch, mm: wire up memfd_secret system call where relevant

2021-07-08 11:48:21 -07:00