diff options
Diffstat (limited to 'arch/arm64/include/asm/kvm_arm.h')
| -rw-r--r-- | arch/arm64/include/asm/kvm_arm.h | 155 |
1 files changed, 125 insertions, 30 deletions
diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h index b476bc46f0ab..6f602af5263c 100644 --- a/arch/arm64/include/asm/kvm_arm.h +++ b/arch/arm64/include/asm/kvm_arm.h @@ -107,6 +107,7 @@ #define VTCR_EL2_RES1 (1 << 31) #define VTCR_EL2_HD (1 << 22) #define VTCR_EL2_HA (1 << 21) +#define VTCR_EL2_PS_SHIFT TCR_EL2_PS_SHIFT #define VTCR_EL2_PS_MASK TCR_EL2_PS_MASK #define VTCR_EL2_TG0_MASK TCR_TG0_MASK #define VTCR_EL2_TG0_4K TCR_TG0_4K @@ -120,63 +121,150 @@ #define VTCR_EL2_IRGN0_WBWA TCR_IRGN0_WBWA #define VTCR_EL2_SL0_SHIFT 6 #define VTCR_EL2_SL0_MASK (3 << VTCR_EL2_SL0_SHIFT) -#define VTCR_EL2_SL0_LVL1 (1 << VTCR_EL2_SL0_SHIFT) #define VTCR_EL2_T0SZ_MASK 0x3f -#define VTCR_EL2_T0SZ_40B 24 #define VTCR_EL2_VS_SHIFT 19 #define VTCR_EL2_VS_8BIT (0 << VTCR_EL2_VS_SHIFT) #define VTCR_EL2_VS_16BIT (1 << VTCR_EL2_VS_SHIFT) +#define VTCR_EL2_T0SZ(x) TCR_T0SZ(x) + /* * We configure the Stage-2 page tables to always restrict the IPA space to be * 40 bits wide (T0SZ = 24). Systems with a PARange smaller than 40 bits are * not known to exist and will break with this configuration. * - * VTCR_EL2.PS is extracted from ID_AA64MMFR0_EL1.PARange at boot time - * (see hyp-init.S). + * The VTCR_EL2 is configured per VM and is initialised in kvm_arm_setup_stage2(). * * Note that when using 4K pages, we concatenate two first level page tables * together. With 16K pages, we concatenate 16 first level page tables. * - * The magic numbers used for VTTBR_X in this patch can be found in Tables - * D4-23 and D4-25 in ARM DDI 0487A.b. */ -#define VTCR_EL2_T0SZ_IPA VTCR_EL2_T0SZ_40B #define VTCR_EL2_COMMON_BITS (VTCR_EL2_SH0_INNER | VTCR_EL2_ORGN0_WBWA | \ VTCR_EL2_IRGN0_WBWA | VTCR_EL2_RES1) -#ifdef CONFIG_ARM64_64K_PAGES /* - * Stage2 translation configuration: - * 64kB pages (TG0 = 1) - * 2 level page tables (SL = 1) + * VTCR_EL2:SL0 indicates the entry level for Stage2 translation. + * Interestingly, it depends on the page size. + * See D.10.2.121, VTCR_EL2, in ARM DDI 0487C.a + * + * ----------------------------------------- + * | Entry level | 4K | 16K/64K | + * ------------------------------------------ + * | Level: 0 | 2 | - | + * ------------------------------------------ + * | Level: 1 | 1 | 2 | + * ------------------------------------------ + * | Level: 2 | 0 | 1 | + * ------------------------------------------ + * | Level: 3 | - | 0 | + * ------------------------------------------ + * + * The table roughly translates to : + * + * SL0(PAGE_SIZE, Entry_level) = TGRAN_SL0_BASE - Entry_Level + * + * Where TGRAN_SL0_BASE is a magic number depending on the page size: + * TGRAN_SL0_BASE(4K) = 2 + * TGRAN_SL0_BASE(16K) = 3 + * TGRAN_SL0_BASE(64K) = 3 + * provided we take care of ruling out the unsupported cases and + * Entry_Level = 4 - Number_of_levels. + * */ -#define VTCR_EL2_TGRAN_FLAGS (VTCR_EL2_TG0_64K | VTCR_EL2_SL0_LVL1) -#define VTTBR_X_TGRAN_MAGIC 38 +#ifdef CONFIG_ARM64_64K_PAGES + +#define VTCR_EL2_TGRAN VTCR_EL2_TG0_64K +#define VTCR_EL2_TGRAN_SL0_BASE 3UL + #elif defined(CONFIG_ARM64_16K_PAGES) -/* - * Stage2 translation configuration: - * 16kB pages (TG0 = 2) - * 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 VTCR_EL2_TG0_16K +#define VTCR_EL2_TGRAN_SL0_BASE 3UL + #else /* 4K */ -/* - * Stage2 translation configuration: - * 4kB pages (TG0 = 0) - * 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 VTCR_EL2_TG0_4K +#define VTCR_EL2_TGRAN_SL0_BASE 2UL + #endif -#define VTCR_EL2_FLAGS (VTCR_EL2_COMMON_BITS | VTCR_EL2_TGRAN_FLAGS) -#define VTTBR_X (VTTBR_X_TGRAN_MAGIC - VTCR_EL2_T0SZ_IPA) +#define VTCR_EL2_LVLS_TO_SL0(levels) \ + ((VTCR_EL2_TGRAN_SL0_BASE - (4 - (levels))) << VTCR_EL2_SL0_SHIFT) +#define VTCR_EL2_SL0_TO_LVLS(sl0) \ + ((sl0) + 4 - VTCR_EL2_TGRAN_SL0_BASE) +#define VTCR_EL2_LVLS(vtcr) \ + VTCR_EL2_SL0_TO_LVLS(((vtcr) & VTCR_EL2_SL0_MASK) >> VTCR_EL2_SL0_SHIFT) + +#define VTCR_EL2_FLAGS (VTCR_EL2_COMMON_BITS | VTCR_EL2_TGRAN) +#define VTCR_EL2_IPA(vtcr) (64 - ((vtcr) & VTCR_EL2_T0SZ_MASK)) + +/* + * ARM VMSAv8-64 defines an algorithm for finding the translation table + * descriptors in section D4.2.8 in ARM DDI 0487C.a. + * + * The algorithm defines the expectations on the translation table + * addresses for each level, based on PAGE_SIZE, entry level + * and the translation table size (T0SZ). The variable "x" in the + * algorithm determines the alignment of a table base address at a given + * level and thus determines the alignment of VTTBR:BADDR for stage2 + * page table entry level. + * Since the number of bits resolved at the entry level could vary + * depending on the T0SZ, the value of "x" is defined based on a + * Magic constant for a given PAGE_SIZE and Entry Level. The + * intermediate levels must be always aligned to the PAGE_SIZE (i.e, + * x = PAGE_SHIFT). + * + * The value of "x" for entry level is calculated as : + * x = Magic_N - T0SZ + * + * where Magic_N is an integer depending on the page size and the entry + * level of the page table as below: + * + * -------------------------------------------- + * | Entry level | 4K 16K 64K | + * -------------------------------------------- + * | Level: 0 (4 levels) | 28 | - | - | + * -------------------------------------------- + * | Level: 1 (3 levels) | 37 | 31 | 25 | + * -------------------------------------------- + * | Level: 2 (2 levels) | 46 | 42 | 38 | + * -------------------------------------------- + * | Level: 3 (1 level) | - | 53 | 51 | + * -------------------------------------------- + * + * We have a magic formula for the Magic_N below: + * + * Magic_N(PAGE_SIZE, Level) = 64 - ((PAGE_SHIFT - 3) * Number_of_levels) + * + * where Number_of_levels = (4 - Level). We are only interested in the + * value for Entry_Level for the stage2 page table. + * + * So, given that T0SZ = (64 - IPA_SHIFT), we can compute 'x' as follows: + * + * x = (64 - ((PAGE_SHIFT - 3) * Number_of_levels)) - (64 - IPA_SHIFT) + * = IPA_SHIFT - ((PAGE_SHIFT - 3) * Number of levels) + * + * Here is one way to explain the Magic Formula: + * + * x = log2(Size_of_Entry_Level_Table) + * + * Since, we can resolve (PAGE_SHIFT - 3) bits at each level, and another + * PAGE_SHIFT bits in the PTE, we have : + * + * Bits_Entry_level = IPA_SHIFT - ((PAGE_SHIFT - 3) * (n - 1) + PAGE_SHIFT) + * = IPA_SHIFT - (PAGE_SHIFT - 3) * n - 3 + * where n = number of levels, and since each pointer is 8bytes, we have: + * + * x = Bits_Entry_Level + 3 + * = IPA_SHIFT - (PAGE_SHIFT - 3) * n + * + * The only constraint here is that, we have to find the number of page table + * levels for a given IPA size (which we do, see stage2_pt_levels()) + */ +#define ARM64_VTTBR_X(ipa, levels) ((ipa) - ((levels) * (PAGE_SHIFT - 3))) #define VTTBR_CNP_BIT (UL(1)) -#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) @@ -224,6 +312,13 @@ /* Hyp Prefetch Fault Address Register (HPFAR/HDFAR) */ #define HPFAR_MASK (~UL(0xf)) +/* + * We have + * PAR [PA_Shift - 1 : 12] = PA [PA_Shift - 1 : 12] + * HPFAR [PA_Shift - 9 : 4] = FIPA [PA_Shift - 1 : 12] + */ +#define PAR_TO_HPFAR(par) \ + (((par) & GENMASK_ULL(PHYS_MASK_SHIFT - 1, 12)) >> 8) #define kvm_arm_exception_type \ {0, "IRQ" }, \ |