On Tue, Feb 22, 2022 at 10:55 AM Mark Rutland <mark.rutland@xxxxxxx> wrote: > > On Tue, Feb 22, 2022 at 08:51:05AM -0800, Kalesh Singh wrote: > > Maps the stack pages in the flexible private VA range and allocates > > guard pages below the stack as unbacked VA space. The stack is aligned > > to twice its size to aid overflow detection (implemented in a subsequent > > patch in the series). > > > > Signed-off-by: Kalesh Singh <kaleshsingh@xxxxxxxxxx> > > --- > > arch/arm64/kvm/hyp/nvhe/setup.c | 25 +++++++++++++++++++++---- > > 1 file changed, 21 insertions(+), 4 deletions(-) > > > > diff --git a/arch/arm64/kvm/hyp/nvhe/setup.c b/arch/arm64/kvm/hyp/nvhe/setup.c > > index 27af337f9fea..69df21320b09 100644 > > --- a/arch/arm64/kvm/hyp/nvhe/setup.c > > +++ b/arch/arm64/kvm/hyp/nvhe/setup.c > > @@ -105,11 +105,28 @@ static int recreate_hyp_mappings(phys_addr_t phys, unsigned long size, > > if (ret) > > return ret; > > > > - end = (void *)per_cpu_ptr(&kvm_init_params, i)->stack_hyp_va; > > + /* > > + * Private mappings are allocated upwards from __io_map_base > > + * so allocate the guard page first then the stack. > > + */ > > + start = (void *)pkvm_alloc_private_va_range(PAGE_SIZE, PAGE_SIZE); > > + if (IS_ERR_OR_NULL(start)) > > + return PTR_ERR(start); > > As on a prior patch, this usage of PTR_ERR() pattern is wrong when the > ptr is NULL. Ack. I'll fix these in the next version. Thanks, Kalesh > > > + /* > > + * The stack is aligned to twice its size to facilitate overflow > > + * detection. > > + */ > > + end = (void *)per_cpu_ptr(&kvm_init_params, i)->stack_pa; > > start = end - PAGE_SIZE; > > - ret = pkvm_create_mappings(start, end, PAGE_HYP); > > - if (ret) > > - return ret; > > + start = (void *)__pkvm_create_private_mapping((phys_addr_t)start, > > + PAGE_SIZE, PAGE_SIZE * 2, PAGE_HYP); > > + if (IS_ERR_OR_NULL(start)) > > + return PTR_ERR(start); > > Likewise. > > Thanks, > Mark. > > > + end = start + PAGE_SIZE; > > + > > + /* Update stack_hyp_va to end of the stack's private VA range */ > > + per_cpu_ptr(&kvm_init_params, i)->stack_hyp_va = (unsigned long) end; > > } > > > > /* > > -- > > 2.35.1.473.g83b2b277ed-goog > > _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
