Hi Quentin,
On Mon, Jul 19, 2021 at 11:48 AM Quentin Perret <qperret@xxxxxxxxxx> wrote:
>
> Refactor the hypervisor stage-1 locking in nVHE protected mode to expose
> a new pkvm_create_mappings_locked() function. This will be used in later
> patches to allow walking and changing the hypervisor stage-1 without
> releasing the lock.
>
> Signed-off-by: Quentin Perret <qperret@xxxxxxxxxx>
> ---
> arch/arm64/kvm/hyp/include/nvhe/mm.h | 1 +
> arch/arm64/kvm/hyp/nvhe/mm.c | 16 ++++++++++++++--
> 2 files changed, 15 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm64/kvm/hyp/include/nvhe/mm.h b/arch/arm64/kvm/hyp/include/nvhe/mm.h
> index 8ec3a5a7744b..c76d7136ed9b 100644
> --- a/arch/arm64/kvm/hyp/include/nvhe/mm.h
> +++ b/arch/arm64/kvm/hyp/include/nvhe/mm.h
> @@ -23,6 +23,7 @@ int hyp_map_vectors(void);
> int hyp_back_vmemmap(phys_addr_t phys, unsigned long size, phys_addr_t back);
> int pkvm_cpu_set_vector(enum arm64_hyp_spectre_vector slot);
> int pkvm_create_mappings(void *from, void *to, enum kvm_pgtable_prot prot);
> +int pkvm_create_mappings_locked(void *from, void *to, enum kvm_pgtable_prot prot);
> int __pkvm_create_mappings(unsigned long start, unsigned long size,
> unsigned long phys, enum kvm_pgtable_prot prot);
> unsigned long __pkvm_create_private_mapping(phys_addr_t phys, size_t size,
The locking logic seems to be consistent, with pkvm_create_mappings()
holding the lock for the whole duration of the operation rather than
per-iteration.
It would be nice though to document which lock should be held for the
_locked versions.
Thanks,
/fuad
> diff --git a/arch/arm64/kvm/hyp/nvhe/mm.c b/arch/arm64/kvm/hyp/nvhe/mm.c
> index a8efdf0f9003..dde22e2a322a 100644
> --- a/arch/arm64/kvm/hyp/nvhe/mm.c
> +++ b/arch/arm64/kvm/hyp/nvhe/mm.c
> @@ -67,7 +67,7 @@ unsigned long __pkvm_create_private_mapping(phys_addr_t phys, size_t size,
> return addr;
> }
>
> -int pkvm_create_mappings(void *from, void *to, enum kvm_pgtable_prot prot)
> +int pkvm_create_mappings_locked(void *from, void *to, enum kvm_pgtable_prot prot)
> {
> unsigned long start = (unsigned long)from;
> unsigned long end = (unsigned long)to;
> @@ -81,7 +81,8 @@ int pkvm_create_mappings(void *from, void *to, enum kvm_pgtable_prot prot)
> int err;
>
> phys = hyp_virt_to_phys((void *)virt_addr);
> - err = __pkvm_create_mappings(virt_addr, PAGE_SIZE, phys, prot);
> + err = kvm_pgtable_hyp_map(&pkvm_pgtable, virt_addr, PAGE_SIZE,
> + phys, prot);
> if (err)
> return err;
> }
> @@ -89,6 +90,17 @@ int pkvm_create_mappings(void *from, void *to, enum kvm_pgtable_prot prot)
> return 0;
> }
>
> +int pkvm_create_mappings(void *from, void *to, enum kvm_pgtable_prot prot)
> +{
> + int ret;
> +
> + hyp_spin_lock(&pkvm_pgd_lock);
> + ret = pkvm_create_mappings_locked(from, to, prot);
> + hyp_spin_unlock(&pkvm_pgd_lock);
> +
> + return ret;
> +}
> +
> int hyp_back_vmemmap(phys_addr_t phys, unsigned long size, phys_addr_t back)
> {
> unsigned long start, end;
> --
> 2.32.0.402.g57bb445576-goog
>
_______________________________________________
kvmarm mailing list
kvmarm@xxxxxxxxxxxxxxxxxxxxx
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
