From 38f9e4b905a00047a96fbdc6cefe9ceb4dae34c3 Mon Sep 17 00:00:00 2001 From: Kalesh Singh Date: Mon, 11 Nov 2024 16:32:50 -0800 Subject: [PATCH] arm64: kvm: Introduce nvhe stack size constants Refactor nvhe stack code to use NVHE_STACK_SIZE/SHIFT constants, instead of directly using PAGE_SIZE/SHIFT. This makes the code a bit easier to read, without introducing any functional changes. Cc: Marc Zyngier Cc: Mark Brown Cc: Mark Rutland Cc: Will Deacon Signed-off-by: Kalesh Singh Link: https://lore.kernel.org/r/20241112003336.1375584-1-kaleshsingh@google.com Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/memory.h | 5 ++++- arch/arm64/include/asm/stacktrace/nvhe.h | 2 +- arch/arm64/kvm/arm.c | 18 +++++++++--------- arch/arm64/kvm/hyp/nvhe/host.S | 4 ++-- arch/arm64/kvm/hyp/nvhe/mm.c | 12 ++++++------ arch/arm64/kvm/hyp/nvhe/stacktrace.c | 4 ++-- arch/arm64/kvm/mmu.c | 12 ++++++------ arch/arm64/kvm/stacktrace.c | 6 +++--- 8 files changed, 33 insertions(+), 30 deletions(-) diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h index 8b9f33cf561bb..717829df294ea 100644 --- a/arch/arm64/include/asm/memory.h +++ b/arch/arm64/include/asm/memory.h @@ -145,13 +145,16 @@ #define OVERFLOW_STACK_SIZE SZ_4K +#define NVHE_STACK_SHIFT PAGE_SHIFT +#define NVHE_STACK_SIZE (UL(1) << NVHE_STACK_SHIFT) + /* * With the minimum frame size of [x29, x30], exactly half the combined * sizes of the hyp and overflow stacks is the maximum size needed to * save the unwinded stacktrace; plus an additional entry to delimit the * end. */ -#define NVHE_STACKTRACE_SIZE ((OVERFLOW_STACK_SIZE + PAGE_SIZE) / 2 + sizeof(long)) +#define NVHE_STACKTRACE_SIZE ((OVERFLOW_STACK_SIZE + NVHE_STACK_SIZE) / 2 + sizeof(long)) /* * Alignment of kernel segments (e.g. .text, .data). diff --git a/arch/arm64/include/asm/stacktrace/nvhe.h b/arch/arm64/include/asm/stacktrace/nvhe.h index 44759281d0d43..171f9edef49fc 100644 --- a/arch/arm64/include/asm/stacktrace/nvhe.h +++ b/arch/arm64/include/asm/stacktrace/nvhe.h @@ -47,7 +47,7 @@ static inline void kvm_nvhe_unwind_init(struct unwind_state *state, DECLARE_KVM_NVHE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)], overflow_stack); DECLARE_KVM_NVHE_PER_CPU(struct kvm_nvhe_stacktrace_info, kvm_stacktrace_info); -DECLARE_PER_CPU(unsigned long, kvm_arm_hyp_stack_page); +DECLARE_PER_CPU(unsigned long, kvm_arm_hyp_stack_base); void kvm_nvhe_dump_backtrace(unsigned long hyp_offset); diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index a102c3aebdbc4..9ac45e23770f9 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -61,7 +61,7 @@ static enum kvm_wfx_trap_policy kvm_wfe_trap_policy __read_mostly = KVM_WFX_NOTR DECLARE_KVM_HYP_PER_CPU(unsigned long, kvm_hyp_vector); -DEFINE_PER_CPU(unsigned long, kvm_arm_hyp_stack_page); +DEFINE_PER_CPU(unsigned long, kvm_arm_hyp_stack_base); DECLARE_KVM_NVHE_PER_CPU(struct kvm_nvhe_init_params, kvm_init_params); DECLARE_KVM_NVHE_PER_CPU(struct kvm_cpu_context, kvm_hyp_ctxt); @@ -2339,7 +2339,7 @@ static void __init teardown_hyp_mode(void) free_hyp_pgds(); for_each_possible_cpu(cpu) { - free_page(per_cpu(kvm_arm_hyp_stack_page, cpu)); + free_pages(per_cpu(kvm_arm_hyp_stack_base, cpu), NVHE_STACK_SHIFT - PAGE_SHIFT); free_pages(kvm_nvhe_sym(kvm_arm_hyp_percpu_base)[cpu], nvhe_percpu_order()); if (free_sve) { @@ -2527,15 +2527,15 @@ static int __init init_hyp_mode(void) * Allocate stack pages for Hypervisor-mode */ for_each_possible_cpu(cpu) { - unsigned long stack_page; + unsigned long stack_base; - stack_page = __get_free_page(GFP_KERNEL); - if (!stack_page) { + stack_base = __get_free_pages(GFP_KERNEL, NVHE_STACK_SHIFT - PAGE_SHIFT); + if (!stack_base) { err = -ENOMEM; goto out_err; } - per_cpu(kvm_arm_hyp_stack_page, cpu) = stack_page; + per_cpu(kvm_arm_hyp_stack_base, cpu) = stack_base; } /* @@ -2604,9 +2604,9 @@ static int __init init_hyp_mode(void) */ 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); + char *stack_base = (char *)per_cpu(kvm_arm_hyp_stack_base, cpu); - err = create_hyp_stack(__pa(stack_page), ¶ms->stack_hyp_va); + err = create_hyp_stack(__pa(stack_base), ¶ms->stack_hyp_va); if (err) { kvm_err("Cannot map hyp stack\n"); goto out_err; @@ -2618,7 +2618,7 @@ static int __init init_hyp_mode(void) * __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_pa = __pa(stack_base); } for_each_possible_cpu(cpu) { diff --git a/arch/arm64/kvm/hyp/nvhe/host.S b/arch/arm64/kvm/hyp/nvhe/host.S index 3d610fc51f4d3..58f0cb2298cc2 100644 --- a/arch/arm64/kvm/hyp/nvhe/host.S +++ b/arch/arm64/kvm/hyp/nvhe/host.S @@ -188,12 +188,12 @@ SYM_FUNC_END(__host_hvc) /* * Test whether the SP has overflowed, without corrupting a GPR. - * nVHE hypervisor stacks are aligned so that the PAGE_SHIFT bit + * nVHE hypervisor stacks are aligned so that the NVHE_STACK_SHIFT bit * of SP should always be 1. */ add sp, sp, x0 // sp' = sp + x0 sub x0, sp, x0 // x0' = sp' - x0 = (sp + x0) - x0 = sp - tbz x0, #PAGE_SHIFT, .L__hyp_sp_overflow\@ + tbz x0, #NVHE_STACK_SHIFT, .L__hyp_sp_overflow\@ sub x0, sp, x0 // x0'' = sp' - x0' = (sp + x0) - sp = x0 sub sp, sp, x0 // sp'' = sp' - x0 = (sp + x0) - x0 = sp diff --git a/arch/arm64/kvm/hyp/nvhe/mm.c b/arch/arm64/kvm/hyp/nvhe/mm.c index 8850b591d7751..f41c7440b34b4 100644 --- a/arch/arm64/kvm/hyp/nvhe/mm.c +++ b/arch/arm64/kvm/hyp/nvhe/mm.c @@ -360,10 +360,10 @@ int pkvm_create_stack(phys_addr_t phys, unsigned long *haddr) prev_base = __io_map_base; /* - * Efficient stack verification using the PAGE_SHIFT bit implies + * Efficient stack verification using the NVHE_STACK_SHIFT bit implies * an alignment of our allocation on the order of the size. */ - size = PAGE_SIZE * 2; + size = NVHE_STACK_SIZE * 2; addr = ALIGN(__io_map_base, size); ret = __pkvm_alloc_private_va_range(addr, size); @@ -373,12 +373,12 @@ int pkvm_create_stack(phys_addr_t phys, unsigned long *haddr) * at the higher address and leave the lower guard page * unbacked. * - * Any valid stack address now has the PAGE_SHIFT bit as 1 + * Any valid stack address now has the NVHE_STACK_SHIFT bit as 1 * and addresses corresponding to the guard page have the - * PAGE_SHIFT bit as 0 - this is used for overflow detection. + * NVHE_STACK_SHIFT bit as 0 - this is used for overflow detection. */ - ret = kvm_pgtable_hyp_map(&pkvm_pgtable, addr + PAGE_SIZE, - PAGE_SIZE, phys, PAGE_HYP); + ret = kvm_pgtable_hyp_map(&pkvm_pgtable, addr + NVHE_STACK_SIZE, + NVHE_STACK_SIZE, phys, PAGE_HYP); if (ret) __io_map_base = prev_base; } diff --git a/arch/arm64/kvm/hyp/nvhe/stacktrace.c b/arch/arm64/kvm/hyp/nvhe/stacktrace.c index ed6b58b19cfa5..5b6eeab1a7743 100644 --- a/arch/arm64/kvm/hyp/nvhe/stacktrace.c +++ b/arch/arm64/kvm/hyp/nvhe/stacktrace.c @@ -28,7 +28,7 @@ static void hyp_prepare_backtrace(unsigned long fp, unsigned long pc) struct kvm_nvhe_stacktrace_info *stacktrace_info = this_cpu_ptr(&kvm_stacktrace_info); struct kvm_nvhe_init_params *params = this_cpu_ptr(&kvm_init_params); - stacktrace_info->stack_base = (unsigned long)(params->stack_hyp_va - PAGE_SIZE); + stacktrace_info->stack_base = (unsigned long)(params->stack_hyp_va - NVHE_STACK_SIZE); stacktrace_info->overflow_stack_base = (unsigned long)this_cpu_ptr(overflow_stack); stacktrace_info->fp = fp; stacktrace_info->pc = pc; @@ -54,7 +54,7 @@ static struct stack_info stackinfo_get_hyp(void) { struct kvm_nvhe_init_params *params = this_cpu_ptr(&kvm_init_params); unsigned long high = params->stack_hyp_va; - unsigned long low = high - PAGE_SIZE; + unsigned long low = high - NVHE_STACK_SIZE; return (struct stack_info) { .low = low, diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index d36be6d2ac91b..8850741243bb5 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -706,10 +706,10 @@ int create_hyp_stack(phys_addr_t phys_addr, unsigned long *haddr) mutex_lock(&kvm_hyp_pgd_mutex); /* - * Efficient stack verification using the PAGE_SHIFT bit implies + * Efficient stack verification using the NVHE_STACK_SHIFT bit implies * an alignment of our allocation on the order of the size. */ - size = PAGE_SIZE * 2; + size = NVHE_STACK_SIZE * 2; base = ALIGN_DOWN(io_map_base - size, size); ret = __hyp_alloc_private_va_range(base); @@ -726,12 +726,12 @@ int create_hyp_stack(phys_addr_t phys_addr, unsigned long *haddr) * at the higher address and leave the lower guard page * unbacked. * - * Any valid stack address now has the PAGE_SHIFT bit as 1 + * Any valid stack address now has the NVHE_STACK_SHIFT bit as 1 * and addresses corresponding to the guard page have the - * PAGE_SHIFT bit as 0 - this is used for overflow detection. + * NVHE_STACK_SHIFT bit as 0 - this is used for overflow detection. */ - ret = __create_hyp_mappings(base + PAGE_SIZE, PAGE_SIZE, phys_addr, - PAGE_HYP); + ret = __create_hyp_mappings(base + NVHE_STACK_SIZE, NVHE_STACK_SIZE, + phys_addr, PAGE_HYP); if (ret) kvm_err("Cannot map hyp stack\n"); diff --git a/arch/arm64/kvm/stacktrace.c b/arch/arm64/kvm/stacktrace.c index fdedd8a3ed6f9..af5eec6811279 100644 --- a/arch/arm64/kvm/stacktrace.c +++ b/arch/arm64/kvm/stacktrace.c @@ -51,7 +51,7 @@ static struct stack_info stackinfo_get_hyp(void) struct kvm_nvhe_stacktrace_info *stacktrace_info = this_cpu_ptr_nvhe_sym(kvm_stacktrace_info); unsigned long low = (unsigned long)stacktrace_info->stack_base; - unsigned long high = low + PAGE_SIZE; + unsigned long high = low + NVHE_STACK_SIZE; return (struct stack_info) { .low = low, @@ -61,8 +61,8 @@ static struct stack_info stackinfo_get_hyp(void) static struct stack_info stackinfo_get_hyp_kern_va(void) { - unsigned long low = (unsigned long)*this_cpu_ptr(&kvm_arm_hyp_stack_page); - unsigned long high = low + PAGE_SIZE; + unsigned long low = (unsigned long)*this_cpu_ptr(&kvm_arm_hyp_stack_base); + unsigned long high = low + NVHE_STACK_SIZE; return (struct stack_info) { .low = low,