On Tue, Nov 14, 2017 at 02:37:43PM +0000, Kristina Martsenko wrote:
VTTBR_BADDR_MASK is used to sanity check the size and alignment of the VTTBR address. It seems to currently be off by one, thereby only allowing up to 47-bit addresses (instead of 48-bit) and also insufficiently checking the alignment. This patch fixes it.
As an example, with 4k pages, before this patch we have:
PHYS_MASK_SHIFT = 48 VTTBR_X = 37 - 24 = 13 VTTBR_BADDR_SHIFT = 13 - 1 = 12 VTTBR_BADDR_MASK = ((1 << 35) - 1) << 12 = 0x00007ffffffff000
Which is wrong, because the mask doesn't allow bit 47 of the VTTBR address to be set, and only requires the address to be 12-bit (4k) aligned, while it actually needs to be 13-bit (8k) aligned because we concatenate two 4k tables.
With this patch, the mask becomes 0x0000ffffffffe000, which is what we want.
Fixes: 0369f6a34b9f ("arm64: KVM: EL2 register definitions") Cc: stable@vger.kernel.org # 3.11.x Reviewed-by: Suzuki K Poulose suzuki.poulose@arm.com Signed-off-by: Kristina Martsenko kristina.martsenko@arm.com
arch/arm64/include/asm/kvm_arm.h | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h index 61d694c2eae5..555d463c0eaa 100644 --- a/arch/arm64/include/asm/kvm_arm.h +++ b/arch/arm64/include/asm/kvm_arm.h @@ -170,8 +170,7 @@ #define VTCR_EL2_FLAGS (VTCR_EL2_COMMON_BITS | VTCR_EL2_TGRAN_FLAGS) #define VTTBR_X (VTTBR_X_TGRAN_MAGIC - VTCR_EL2_T0SZ_IPA) -#define VTTBR_BADDR_SHIFT (VTTBR_X - 1) -#define VTTBR_BADDR_MASK (((UL(1) << (PHYS_MASK_SHIFT - VTTBR_X)) - 1) << VTTBR_BADDR_SHIFT) +#define VTTBR_BADDR_MASK (((UL(1) << (PHYS_MASK_SHIFT - VTTBR_X)) - 1) << VTTBR_X) #define VTTBR_VMID_SHIFT (UL(48)) #define VTTBR_VMID_MASK(size) (_AT(u64, (1 << size) - 1) << VTTBR_VMID_SHIFT) -- 2.1.4
Reviewed-by: Christoffer Dall christoffer.dall@linaro.org