Subject: [PATCH 3/6] arm/arm64: KVM: add 'writable' parameter to kvm_phys_addr_ioremap

From: [email-masked] (Marc Zyngier)
Date: Thu, 09 Oct 2014 14:46:42 +0100

On 09/10/14 14:11, Ard Biesheuvel wrote:
> On 9 October 2014 15:07, Marc Zyngier <[email-masked]> wrote:
>> On 17/09/14 22:56, Ard Biesheuvel wrote:
>>> Add support for read-only MMIO passthrough mappings by adding a
>>> 'writable' parameter to kvm_phys_addr_ioremap. For the moment,
>>> mappings will be read-write even if 'writable' is false, but once
>>> the definition of PAGE_S2_DEVICE gets changed, those mappings will
>>> be created read-only.
>>>
>>> Signed-off-by: Ard Biesheuvel <[email-masked]>
>>> ---
>>>  arch/arm/kvm/mmu.c               | 5 ++++-
>>>  arch/arm64/include/asm/kvm_mmu.h | 2 +-
>>>  virt/kvm/arm/vgic.c              | 3 ++-
>>>  3 files changed, 7 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
>>> index c093e95ff7ef..fe53c3a30383 100644
>>> --- a/arch/arm/kvm/mmu.c
>>> +++ b/arch/arm/kvm/mmu.c
>>> @@ -674,7 +674,7 @@ static int stage2_set_pte(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
>>>   * @size:    The size of the mapping
>>>   */
>>>  int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,
>>> -                       phys_addr_t pa, unsigned long size)
>>> +                       phys_addr_t pa, unsigned long size, bool writable)
>>>  {
>>>       phys_addr_t addr, end;
>>>       int ret = 0;
>>> @@ -687,6 +687,9 @@ int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,
>>>       for (addr = guest_ipa; addr < end; addr += PAGE_SIZE) {
>>>               pte_t pte = pfn_pte(pfn, PAGE_S2_DEVICE);
>>>
>>> +             if (writable)
>>> +                     kvm_set_s2pte_writable(&pte);
>>> +
>>>               ret = mmu_topup_memory_cache(&cache, 2, 2);
>>>               if (ret)
>>>                       goto out;
>>> diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
>>> index 737da742b293..7474e611bb2a 100644
>>> --- a/arch/arm64/include/asm/kvm_mmu.h
>>> +++ b/arch/arm64/include/asm/kvm_mmu.h
>>> @@ -78,7 +78,7 @@ void free_hyp_pgds(void);
>>>  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);
>>> +                       phys_addr_t pa, unsigned long size, bool writable);
>>
>> I'm afraid you missed the equivalent 32bit declaration.
>>
> 
> Christoffer had spotted that as well, and indicated he would not mind
> fixing it up when applying.

Ah, missed that. In which case:

Acked-by: Marc Zyngier <[email-masked]>

	M.
-- 
Jazz is not dead. It just smells funny...