On Mon, May 14, 2012 at 4:05 PM, Marc Zyngier <marc.zyngier at arm.com> wrote:
> Moving to the VGIC implies giving access to some io devices
> (the VGIC virtual CPU interface registers) to the guest.
>
> Define kvm_phys_addr_ioremap() to map a device at a guest IPA.
>
> Signed-off-by: Marc Zyngier <marc.zyngier at arm.com>
> ---
> ?arch/arm/include/asm/kvm_mmu.h | ? ?2 ++
> ?arch/arm/kvm/mmu.c ? ? ? ? ? ? | ? 36 ++++++++++++++++++++++++++++++++++--
> ?2 files changed, 36 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h
> index eb05401..71d6df4 100644
> --- a/arch/arm/include/asm/kvm_mmu.h
> +++ b/arch/arm/include/asm/kvm_mmu.h
> @@ -36,6 +36,8 @@ void free_hyp_pmds(pgd_t *hyp_pgd);
>
> ?int kvm_alloc_stage2_pgd(struct kvm *kvm);
> ?void kvm_free_stage2_pgd(struct kvm *kvm);
> +int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,
> + ? ? ? ? ? ? ? ? ? ? ? ? phys_addr_t pa, unsigned long size);
>
> ?int kvm_handle_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run);
> ?int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run);
> diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
> index 5c809b8..36bccaa 100644
> --- a/arch/arm/kvm/mmu.c
> +++ b/arch/arm/kvm/mmu.c
> @@ -240,10 +240,15 @@ static void free_guest_pages(pte_t *pte, unsigned long addr)
> ? ? ? ?pte_page = virt_to_page(pte);
>
> ? ? ? ?for (i = 0; i < PTRS_PER_PTE; i++, addr += PAGE_SIZE) {
> + ? ? ? ? ? ? ? unsigned long pfn;
> +
> ? ? ? ? ? ? ? ?if (!pte_present(*pte))
> ? ? ? ? ? ? ? ? ? ? ? ?goto next_page;
> - ? ? ? ? ? ? ? page = pfn_to_page(pte_pfn(*pte));
> - ? ? ? ? ? ? ? put_page(page);
> + ? ? ? ? ? ? ? pfn = pte_pfn(*pte);
> + ? ? ? ? ? ? ? if (pfn_valid(pfn)) { /* Skip over device memory */
> + ? ? ? ? ? ? ? ? ? ? ? page = pfn_to_page(pfn);
> + ? ? ? ? ? ? ? ? ? ? ? put_page(page);
> + ? ? ? ? ? ? ? }
> ? ? ? ? ? ? ? ?put_page(pte_page);
> ?next_page:
> ? ? ? ? ? ? ? ?pte++;
> @@ -438,6 +443,33 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
> ? ? ? ?return ret;
> ?}
>
> +int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,
> + ? ? ? ? ? ? ? ? ? ? ? ? phys_addr_t pa, unsigned long size)
> +{
> + ? ? ? phys_addr_t addr, end;
> + ? ? ? pgprot_t prot;
> + ? ? ? int ret = 0;
> + ? ? ? unsigned long pfn;
> +
> + ? ? ? end = (guest_ipa + size + PAGE_SIZE - 1) & PAGE_MASK;
> + ? ? ? prot = __pgprot(get_mem_type_prot_pte(MT_DEVICE) | L_PTE_USER | L_PTE2_READ | L_PTE2_WRITE);
> + ? ? ? pfn = __phys_to_pfn(pa);
> +
> + ? ? ? mutex_lock(&kvm->arch.pgd_mutex);
> + ? ? ? for (addr = guest_ipa; addr < end; addr += PAGE_SIZE) {
> + ? ? ? ? ? ? ? pte_t pte = pfn_pte(pfn, prot);
> +
> + ? ? ? ? ? ? ? ret = stage2_set_pte(kvm, addr, &pte);
> + ? ? ? ? ? ? ? if (ret)
> + ? ? ? ? ? ? ? ? ? ? ? break;
> +
> + ? ? ? ? ? ? ? pfn++;
> + ? ? ? }
> + ? ? ? mutex_unlock(&kvm->arch.pgd_mutex);
> +
> + ? ? ? return ret;
> +}
> +
besides the 80-char formatting breakage and missing docs (I can easily
add those when creating the next flattened patch series), it looks
good to me.
-Christoffer
