diff options
Diffstat (limited to 'arch/arm64/kvm/arm.c')
| -rw-r--r-- | arch/arm64/kvm/arm.c | 37 |
1 files changed, 34 insertions, 3 deletions
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index e7cb8a4d2e81..cee02ea86159 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -1479,7 +1479,6 @@ static void cpu_prepare_hyp_mode(int cpu) tcr |= (idmap_t0sz & GENMASK(TCR_TxSZ_WIDTH - 1, 0)) << TCR_T0SZ_OFFSET; params->tcr_el2 = tcr; - params->stack_hyp_va = kern_hyp_va(per_cpu(kvm_arm_hyp_stack_page, cpu) + PAGE_SIZE); params->pgd_pa = kvm_mmu_get_httbr(); if (is_protected_kvm_enabled()) params->hcr_el2 = HCR_HOST_NVHE_PROTECTED_FLAGS; @@ -1929,14 +1928,46 @@ static int init_hyp_mode(void) * Map the Hyp stack pages */ for_each_possible_cpu(cpu) { + struct kvm_nvhe_init_params *params = per_cpu_ptr_nvhe_sym(kvm_init_params, cpu); char *stack_page = (char *)per_cpu(kvm_arm_hyp_stack_page, cpu); - err = create_hyp_mappings(stack_page, stack_page + PAGE_SIZE, - PAGE_HYP); + unsigned long hyp_addr; + /* + * Allocate a contiguous HYP private VA range for the stack + * and guard page. The allocation is also aligned based on + * the order of its size. + */ + err = hyp_alloc_private_va_range(PAGE_SIZE * 2, &hyp_addr); + if (err) { + kvm_err("Cannot allocate hyp stack guard page\n"); + goto out_err; + } + + /* + * Since the stack grows downwards, map the stack to the page + * at the higher address and leave the lower guard page + * unbacked. + * + * Any valid stack address now has the PAGE_SHIFT bit as 1 + * and addresses corresponding to the guard page have the + * PAGE_SHIFT bit as 0 - this is used for overflow detection. + */ + err = __create_hyp_mappings(hyp_addr + PAGE_SIZE, PAGE_SIZE, + __pa(stack_page), PAGE_HYP); if (err) { kvm_err("Cannot map hyp stack\n"); goto out_err; } + + /* + * Save the stack PA in nvhe_init_params. This will be needed + * to recreate the stack mapping in protected nVHE mode. + * __hyp_pa() won't do the right thing there, since the stack + * has been mapped in the flexible private VA space. + */ + params->stack_pa = __pa(stack_page); + + params->stack_hyp_va = hyp_addr + (2 * PAGE_SIZE); } for_each_possible_cpu(cpu) { |