KVM: arm64: Avoid setting the upper 32 bits of TCR_EL2 and CPTR_EL2 to 1
authorCatalin Marinas <catalin.marinas@arm.com>
Thu, 25 Nov 2021 15:20:14 +0000 (15:20 +0000)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 8 Dec 2021 08:03:22 +0000 (09:03 +0100)
commitc71b5f37b5ff1a673b2e4a91d1b34ea027546e23
tree275f4e2fb9b01e0c0478ece938d3fb7b5c98d93c
parent5f33887a36824f1e906863460535be5d841a4364
KVM: arm64: Avoid setting the upper 32 bits of TCR_EL2 and CPTR_EL2 to 1

commit 1f80d15020d7f130194821feb1432b67648c632d 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 df655b75c43f
("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>
arch/arm64/include/asm/kvm_arm.h