Hi Suzuki, On 06/29/2018 01:15 PM, Suzuki K Poulose wrote: > 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 compute > 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 update ref to the last one? > + * > + * ----------------------------------------- > + * | 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. > * > Reviewed-by: Eric Auger <eric.auger@xxxxxxxxxx> Thanks Eric
