VTCR_EL2 holds the following key stage2 translation table parameters: SL0 - Entry level in the page table lookup. T0SZ - Denotes the size of the memory addressed by the table. We have been using fixed values for the SL0 depending on the page size as we have a fixed IPA size. But since we are about to make it dynamic, we need to calculate the SL0 at runtime per VM. This patch adds a helper to comput the value of SL0 for a given IPA. Cc: Marc Zyngier <marc.zyngier@xxxxxxx> Cc: Christoffer Dall <cdall@xxxxxxx> Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx> --- Changes since v2: - Part 2 of split from VTCR & VTTBR dynamic configuration --- arch/arm64/include/asm/kvm_arm.h | 35 ++++++++++++++++++++++++++++++++--- 1 file changed, 32 insertions(+), 3 deletions(-) diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h index c557f45..11a7db0 100644 --- a/arch/arm64/include/asm/kvm_arm.h +++ b/arch/arm64/include/asm/kvm_arm.h @@ -153,7 +153,8 @@ * 2 level page tables (SL = 1) */ #define VTCR_EL2_TGRAN_FLAGS (VTCR_EL2_TG0_64K | VTCR_EL2_SL0_LVL1) -#define VTTBR_X_TGRAN_MAGIC 38 +#define VTCR_EL2_TGRAN_SL0_BASE 3UL + #elif defined(CONFIG_ARM64_16K_PAGES) /* * Stage2 translation configuration: @@ -161,7 +162,7 @@ * 2 level page tables (SL = 1) */ #define VTCR_EL2_TGRAN_FLAGS (VTCR_EL2_TG0_16K | VTCR_EL2_SL0_LVL1) -#define VTTBR_X_TGRAN_MAGIC 42 +#define VTCR_EL2_TGRAN_SL0_BASE 3UL #else /* 4K */ /* * Stage2 translation configuration: @@ -169,11 +170,39 @@ * 3 level page tables (SL = 1) */ #define VTCR_EL2_TGRAN_FLAGS (VTCR_EL2_TG0_4K | VTCR_EL2_SL0_LVL1) -#define VTTBR_X_TGRAN_MAGIC 37 +#define VTCR_EL2_TGRAN_SL0_BASE 2UL #endif #define VTCR_EL2_FLAGS (VTCR_EL2_COMMON_BITS | VTCR_EL2_TGRAN_FLAGS) /* + * VTCR_EL2:SL0 indicates the entry level for Stage2 translation. + * Interestingly, it depends on the page size. + * See D.10.2.110, VTCR_EL2, in ARM DDI 0487B.b + * + * ----------------------------------------- + * | Entry level | 4K | 16K/64K | + * ------------------------------------------ + * | Level: 0 | 2 | - | + * ------------------------------------------ + * | Level: 1 | 1 | 2 | + * ------------------------------------------ + * | Level: 2 | 0 | 1 | + * ------------------------------------------ + * | Level: 3 | - | 0 | + * ------------------------------------------ + * + * That table roughly translates to : + * + * SL0(PAGE_SIZE, Entry_level) = SL0_BASE(PAGE_SIZE) - Entry_Level + * + * Where SL0_BASE(4K) = 2 and SL0_BASE(16K) = 3, SL0_BASE(64K) = 3, provided + * we take care of ruling out the unsupported cases and + * Entry_Level = 4 - Number_of_levels. + * + */ +#define VTCR_EL2_SL0(levels) \ + ((VTCR_EL2_TGRAN_SL0_BASE - (4 - (levels))) << VTCR_EL2_SL0_SHIFT) +/* * ARM VMSAv8-64 defines an algorithm for finding the translation table * descriptors in section D4.2.8 in ARM DDI 0487B.b. * -- 2.7.4
