On Thu, Feb 24, 2022 at 4:25 AM Fuad Tabba <tabba@xxxxxxxxxx> wrote: > > Hi Kalesh, > > On Thu, Feb 24, 2022 at 5:16 AM Kalesh Singh <kaleshsingh@xxxxxxxxxx> wrote: > > > > hyp_alloc_private_va_range() can be used to reserve private VA ranges > > in the nVHE hypervisor. Also update __create_hyp_private_mapping() > > to allow specifying an alignment for the private VA mapping. > > > > These will be used to implement stack guard pages for KVM nVHE hypervisor > > (nVHE Hyp mode / not pKVM), in a subsequent patch in the series. > > > > Signed-off-by: Kalesh Singh <kaleshsingh@xxxxxxxxxx> > > --- > > > > Changes in v3: > > - Handle null ptr in IS_ERR_OR_NULL checks, per Mark > > > > arch/arm64/include/asm/kvm_mmu.h | 4 +++ > > arch/arm64/kvm/mmu.c | 62 ++++++++++++++++++++------------ > > 2 files changed, 43 insertions(+), 23 deletions(-) > > > > diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h > > index 81839e9a8a24..0b0c71302b92 100644 > > --- a/arch/arm64/include/asm/kvm_mmu.h > > +++ b/arch/arm64/include/asm/kvm_mmu.h > > @@ -153,6 +153,10 @@ static __always_inline unsigned long __kern_hyp_va(unsigned long v) > > int kvm_share_hyp(void *from, void *to); > > void kvm_unshare_hyp(void *from, void *to); > > int create_hyp_mappings(void *from, void *to, enum kvm_pgtable_prot prot); > > +unsigned long hyp_alloc_private_va_range(size_t size, size_t align); > > +int __create_hyp_private_mapping(phys_addr_t phys_addr, size_t size, > > + size_t align, unsigned long *haddr, > > + enum kvm_pgtable_prot prot); > > int create_hyp_io_mappings(phys_addr_t phys_addr, size_t size, > > void __iomem **kaddr, > > void __iomem **haddr); > > diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c > > index bc2aba953299..fc09536c8197 100644 > > --- a/arch/arm64/kvm/mmu.c > > +++ b/arch/arm64/kvm/mmu.c > > @@ -457,22 +457,16 @@ int create_hyp_mappings(void *from, void *to, enum kvm_pgtable_prot prot) > > return 0; > > } > > > > -static int __create_hyp_private_mapping(phys_addr_t phys_addr, size_t size, > > - unsigned long *haddr, > > - enum kvm_pgtable_prot prot) > > + > > +/* > > + * Allocates a private VA range below io_map_base. > > + * > > + * @size: The size of the VA range to reserve. > > + * @align: The required alignment for the allocation. > > + */ > > Many of the functions in this file use the kernel-doc format, and your > added comments are close, but not quite conforment. If you want to use > the kernel-doc for these you can refer to: > https://www.kernel.org/doc/html/latest/doc-guide/kernel-doc.html Hi Fuad, Thanks for the pointer. I will update the function comments to match when I send the next version. > > > +unsigned long hyp_alloc_private_va_range(size_t size, size_t align) > > { > > unsigned long base; > > - int ret = 0; > > - > > - if (!kvm_host_owns_hyp_mappings()) { > > - base = kvm_call_hyp_nvhe(__pkvm_create_private_mapping, > > - phys_addr, size, prot); > > - if (IS_ERR_OR_NULL((void *)base)) > > - return PTR_ERR((void *)base); > > - *haddr = base; > > - > > - return 0; > > - } > > > > mutex_lock(&kvm_hyp_pgd_mutex); > > > > @@ -484,8 +478,8 @@ static int __create_hyp_private_mapping(phys_addr_t phys_addr, size_t size, > > * > > * The allocated size is always a multiple of PAGE_SIZE. > > */ > > - size = PAGE_ALIGN(size + offset_in_page(phys_addr)); > > - base = io_map_base - size; > > + base = io_map_base - PAGE_ALIGN(size); > > + base = ALIGN_DOWN(base, align); > > > > /* > > * Verify that BIT(VA_BITS - 1) hasn't been flipped by > > @@ -493,20 +487,42 @@ static int __create_hyp_private_mapping(phys_addr_t phys_addr, size_t size, > > * overflowed the idmap/IO address range. > > */ > > if ((base ^ io_map_base) & BIT(VA_BITS - 1)) > > - ret = -ENOMEM; > > + base = (unsigned long)ERR_PTR(-ENOMEM); > > else > > io_map_base = base; > > > > mutex_unlock(&kvm_hyp_pgd_mutex); > > > > - if (ret) > > - goto out; > > + return base; > > +} > > + > > +int __create_hyp_private_mapping(phys_addr_t phys_addr, size_t size, > > + size_t align, unsigned long *haddr, > > + enum kvm_pgtable_prot prot) > > +{ > > + unsigned long addr; > > + int ret = 0; > > + > > + if (!kvm_host_owns_hyp_mappings()) { > > + addr = kvm_call_hyp_nvhe(__pkvm_create_private_mapping, > > + phys_addr, size, prot); > > + if (IS_ERR_OR_NULL((void *)addr)) > > + return addr ? PTR_ERR((void *)addr) : -ENOMEM; > > + *haddr = addr; > > + > > + return 0; > > + } > > + > > + size += offset_in_page(phys_addr); > > You're not page-aligning the size, which was the behavior before this > patch. However, looking at where it's being used it seems to be fine > because the users of size would align it if necessary. This is now done by hyp_alloc_private_va_range() when calculating the new base: ... * The allocated size is always a multiple of PAGE_SIZE. */ base = io_map_base - PAGE_ALIGN(size); ... Thanks, Kalesh > > Thanks, > /fuad > > > > > + addr = hyp_alloc_private_va_range(size, align); > > + if (IS_ERR_OR_NULL((void *)addr)) > > + return addr ? PTR_ERR((void *)addr) : -ENOMEM; > > > > - ret = __create_hyp_mappings(base, size, phys_addr, prot); > > + ret = __create_hyp_mappings(addr, size, phys_addr, prot); > > if (ret) > > goto out; > > > > - *haddr = base + offset_in_page(phys_addr); > > + *haddr = addr + offset_in_page(phys_addr); > > out: > > return ret; > > } > > @@ -537,7 +553,7 @@ int create_hyp_io_mappings(phys_addr_t phys_addr, size_t size, > > return 0; > > } > > > > - ret = __create_hyp_private_mapping(phys_addr, size, > > + ret = __create_hyp_private_mapping(phys_addr, size, PAGE_SIZE, > > &addr, PAGE_HYP_DEVICE); > > if (ret) { > > iounmap(*kaddr); > > @@ -564,7 +580,7 @@ int create_hyp_exec_mappings(phys_addr_t phys_addr, size_t size, > > > > BUG_ON(is_kernel_in_hyp_mode()); > > > > - ret = __create_hyp_private_mapping(phys_addr, size, > > + ret = __create_hyp_private_mapping(phys_addr, size, PAGE_SIZE, > > &addr, PAGE_HYP_EXEC); > > if (ret) { > > *haddr = NULL; > > -- > > 2.35.1.473.g83b2b277ed-goog > > _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
