From 68344037b764401f751c66661c53334ea1e15324 Mon Sep 17 00:00:00 2001 From: Vincent Donnefort Date: Tue, 7 Jan 2025 11:28:21 +0000 Subject: [PATCH] KVM: arm64: Fix nVHE stacktrace VA bits mask The hypervisor VA space size depends on both the ID map's (IDMAP_VA_BITS) and the kernel stage-1 (VA_BITS). However, the hypervisor stacktrace decoding is solely relying on VA_BITS. This is especially an issue when VA_BITS < IDMAP_VA_BITS (i.e. VA_BITS is 39-bit): the hypervisor may have addresses bigger than the stacktrace is masking. Align this mask with hyp_va_bits. Signed-off-by: Vincent Donnefort Link: https://lore.kernel.org/r/20250107112821.416591-1-vdonnefort@google.com Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/kvm_mmu.h | 2 ++ arch/arm64/kvm/mmu.c | 3 +++ arch/arm64/kvm/stacktrace.c | 3 ++- 3 files changed, 7 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index 66d93e320ec8e..2ddd98fd2df45 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -139,6 +139,8 @@ static __always_inline unsigned long __kern_hyp_va(unsigned long v) #define kern_hyp_va(v) ((typeof(v))(__kern_hyp_va((unsigned long)(v)))) +extern u32 __hyp_va_bits; + /* * We currently support using a VM-specified IPA size. For backward * compatibility, the default IPA size is fixed to 40bits. diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index c9d46ad57e52d..d36be6d2ac91b 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -29,6 +29,8 @@ static unsigned long __ro_after_init hyp_idmap_start; static unsigned long __ro_after_init hyp_idmap_end; static phys_addr_t __ro_after_init hyp_idmap_vector; +u32 __ro_after_init __hyp_va_bits; + static unsigned long __ro_after_init io_map_base; static phys_addr_t __stage2_range_addr_end(phys_addr_t addr, phys_addr_t end, @@ -2056,6 +2058,7 @@ int __init kvm_mmu_init(u32 *hyp_va_bits) goto out_destroy_pgtable; io_map_base = hyp_idmap_start; + __hyp_va_bits = *hyp_va_bits; return 0; out_destroy_pgtable: diff --git a/arch/arm64/kvm/stacktrace.c b/arch/arm64/kvm/stacktrace.c index 3ace5b75813bd..fdedd8a3ed6f9 100644 --- a/arch/arm64/kvm/stacktrace.c +++ b/arch/arm64/kvm/stacktrace.c @@ -19,6 +19,7 @@ #include #include +#include #include static struct stack_info stackinfo_get_overflow(void) @@ -145,7 +146,7 @@ static void unwind(struct unwind_state *state, */ static bool kvm_nvhe_dump_backtrace_entry(void *arg, unsigned long where) { - unsigned long va_mask = GENMASK_ULL(vabits_actual - 1, 0); + unsigned long va_mask = GENMASK_ULL(__hyp_va_bits - 1, 0); unsigned long hyp_offset = (unsigned long)arg; /* Mask tags and convert to kern addr */