KVM: arm64: Avoid setting the upper 32 bits of TCR_EL2 and CPTR_EL2 to 1
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 df655b75 ("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
Showing
Please register or sign in to comment