| Message ID | 20220222165212.2005066-5-kaleshsingh@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: arm64: Hypervisor stack enhancements | expand |
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@google.com> > --- > 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. > + /* > + * 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 >
On Tue, Feb 22, 2022 at 10:55 AM Mark Rutland <mark.rutland@arm.com> 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@google.com> > > --- > > 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 > >
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); + + /* + * 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); + 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; } /*
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@google.com> --- arch/arm64/kvm/hyp/nvhe/setup.c | 25 +++++++++++++++++++++---- 1 file changed, 21 insertions(+), 4 deletions(-)