| Message ID | 20211125152014.2806582-1-catalin.marinas@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: KVM: Avoid setting the upper 32 bits of TCR_EL2 and CPTR_EL2 to 1 | expand |
On Thu, 25 Nov 2021 15:20:14 +0000, Catalin Marinas wrote: > 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. > > [...] Applied to fixes, thanks! [1/1] arm64: KVM: Avoid setting the upper 32 bits of TCR_EL2 and CPTR_EL2 to 1 commit: 1f80d15020d7f130194821feb1432b67648c632d Cheers, M.
diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h index a39fcf318c77..01d47c5886dc 100644 --- a/arch/arm64/include/asm/kvm_arm.h +++ b/arch/arm64/include/asm/kvm_arm.h @@ -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)
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> --- arch/arm64/include/asm/kvm_arm.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)