Allocate and switch to 16-byte aligned secondary stack on overflow. This provides us stack space to better handle overflows; and is used in a subsequent patch to dump the hypervisor stacktrace. The overflow stack is only allocated if CONFIG_NVHE_EL2_DEBUG is enabled, as hypervisor stacktraces is a debug feature dependent on CONFIG_NVHE_EL2_DEBUG. Signed-off-by: Kalesh Singh <kaleshsingh@xxxxxxxxxx> --- arch/arm64/kvm/hyp/nvhe/host.S | 5 +++++ arch/arm64/kvm/hyp/nvhe/setup.c | 5 +++++ 2 files changed, 10 insertions(+) diff --git a/arch/arm64/kvm/hyp/nvhe/host.S b/arch/arm64/kvm/hyp/nvhe/host.S index 78e4b612ac06..751a4b9e429f 100644 --- a/arch/arm64/kvm/hyp/nvhe/host.S +++ b/arch/arm64/kvm/hyp/nvhe/host.S @@ -171,6 +171,10 @@ SYM_FUNC_END(__host_hvc) b hyp_panic .L__hyp_sp_overflow\@: +#ifdef CONFIG_NVHE_EL2_DEBUG + /* Switch to the overflow stack */ + adr_this_cpu sp, hyp_overflow_stack + PAGE_SIZE, x0 +#else /* * Reset SP to the top of the stack, to allow handling the hyp_panic. * This corrupts the stack but is ok, since we won't be attempting @@ -178,6 +182,7 @@ SYM_FUNC_END(__host_hvc) */ ldr_this_cpu x0, kvm_init_params + NVHE_INIT_STACK_HYP_VA, x1 mov sp, x0 +#endif bl hyp_panic_bad_stack ASM_BUG() diff --git a/arch/arm64/kvm/hyp/nvhe/setup.c b/arch/arm64/kvm/hyp/nvhe/setup.c index 114053dff228..39937fa6a1b2 100644 --- a/arch/arm64/kvm/hyp/nvhe/setup.c +++ b/arch/arm64/kvm/hyp/nvhe/setup.c @@ -20,6 +20,11 @@ unsigned long hyp_nr_cpus; +#ifdef CONFIG_NVHE_EL2_DEBUG +DEFINE_PER_CPU(unsigned long [PAGE_SIZE/sizeof(long)], hyp_overflow_stack) + __aligned(16); +#endif + #define hyp_percpu_size ((unsigned long)__per_cpu_end - \ (unsigned long)__per_cpu_start) -- 2.35.1.265.g69c8d7142f-goog _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
