diff options
Diffstat (limited to 'arch/arm64/kvm/va_layout.c')
| -rw-r--r-- | arch/arm64/kvm/va_layout.c | 33 |
1 files changed, 28 insertions, 5 deletions
diff --git a/arch/arm64/kvm/va_layout.c b/arch/arm64/kvm/va_layout.c index 91b22a014610..2346f9435a71 100644 --- a/arch/arm64/kvm/va_layout.c +++ b/arch/arm64/kvm/va_layout.c @@ -47,8 +47,30 @@ static void init_hyp_physvirt_offset(void) } /* + * Calculate the actual VA size used by the hypervisor + */ +__init u32 kvm_hyp_va_bits(void) +{ + /* + * The ID map is always configured for 48 bits of translation, which may + * be different from the number of VA bits used by the regular kernel + * stage 1. + * + * At EL2, there is only one TTBR register, and we can't switch between + * translation tables *and* update TCR_EL2.T0SZ at the same time. Bottom + * line: we need to use the extended range with *both* our translation + * tables. + * + * So use the maximum of the idmap VA bits and the regular kernel stage + * 1 VA bits as the hypervisor VA size to assure that the hypervisor can + * both ID map its code page and map any kernel memory. + */ + return max(IDMAP_VA_BITS, vabits_actual); +} + +/* * We want to generate a hyp VA with the following format (with V == - * vabits_actual): + * hypervisor VA bits): * * 63 ... V | V-1 | V-2 .. tag_lsb | tag_lsb - 1 .. 0 * --------------------------------------------------------- @@ -61,10 +83,11 @@ __init void kvm_compute_layout(void) { phys_addr_t idmap_addr = __pa_symbol(__hyp_idmap_text_start); u64 hyp_va_msb; + u32 hyp_va_bits = kvm_hyp_va_bits(); /* Where is my RAM region? */ - hyp_va_msb = idmap_addr & BIT(vabits_actual - 1); - hyp_va_msb ^= BIT(vabits_actual - 1); + hyp_va_msb = idmap_addr & BIT(hyp_va_bits - 1); + hyp_va_msb ^= BIT(hyp_va_bits - 1); tag_lsb = fls64((u64)phys_to_virt(memblock_start_of_DRAM()) ^ (u64)(high_memory - 1)); @@ -72,9 +95,9 @@ __init void kvm_compute_layout(void) va_mask = GENMASK_ULL(tag_lsb - 1, 0); tag_val = hyp_va_msb; - if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && tag_lsb != (vabits_actual - 1)) { + if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && tag_lsb != (hyp_va_bits - 1)) { /* We have some free bits to insert a random tag. */ - tag_val |= get_random_long() & GENMASK_ULL(vabits_actual - 2, tag_lsb); + tag_val |= get_random_long() & GENMASK_ULL(hyp_va_bits - 2, tag_lsb); } tag_val >>= tag_lsb; |