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

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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
This commit is contained in:
Catalin Marinas 2021-11-25 15:20:14 +00:00 committed by Marc Zyngier
parent 7183b2b5ae
commit 1f80d15020
1 changed files with 2 additions and 2 deletions
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4
arch/arm64/include/asm/kvm_arm.h
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@ -91,7 +91,7 @@
#define HCR_HOST_VHE_FLAGS (HCR_RW | HCR_TGE | HCR_E2H)
/* TCR_EL2 Registers bits */
#define TCR_EL2_RES1 ((1 << 31) | (1 << 23))
#define TCR_EL2_RES1 ((1U << 31) | (1 << 23))
#define TCR_EL2_TBI (1 << 20)
#define TCR_EL2_PS_SHIFT 16
#define TCR_EL2_PS_MASK (7 << TCR_EL2_PS_SHIFT)
@ -276,7 +276,7 @@
#define CPTR_EL2_TFP_SHIFT 10
/* Hyp Coprocessor Trap Register */
#define CPTR_EL2_TCPAC (1 << 31)
#define CPTR_EL2_TCPAC (1U << 31)
#define CPTR_EL2_TAM (1 << 30)
#define CPTR_EL2_TTA (1 << 20)
#define CPTR_EL2_TFP (1 << CPTR_EL2_TFP_SHIFT)