Re: [PATCH v7 1/4] arm: add ARMv7 HYP API to flush VM TLBs without address param

[Mario Smarduch <m.smarduch@samsung.com>]

On 06/09/2014 10:49 AM, Christoffer Dall wrote:
> On Mon, Jun 09, 2014 at 10:06:29AM -0700, Mario Smarduch wrote:
>> On 06/08/2014 05:05 AM, Christoffer Dall wrote:
>>> On Tue, Jun 03, 2014 at 04:19:24PM -0700, Mario Smarduch wrote:
>>>> Patch adds HYP interface for global VM TLB invalidation without address
>>>> parameter. Added ARM version of kvm_flush_remote_tlbs(), made the generic
>>>> implementation a weak symbol.
>>>>
>>>> Signed-off-by: Mario Smarduch <m.smarduch@samsung.com>
>>>> ---
>>>>  arch/arm/include/asm/kvm_asm.h |    1 +
>>>>  arch/arm/kvm/interrupts.S      |   11 +++++++++++
>>>>  arch/arm/kvm/mmu.c             |   14 ++++++++++++++
>>>>  virt/kvm/kvm_main.c            |    2 +-
>>>>  4 files changed, 27 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/arch/arm/include/asm/kvm_asm.h b/arch/arm/include/asm/kvm_asm.h
>>>> index 53b3c4a..21bc519 100644
>>>> --- a/arch/arm/include/asm/kvm_asm.h
>>>> +++ b/arch/arm/include/asm/kvm_asm.h
>>>> @@ -78,6 +78,7 @@ extern char __kvm_hyp_code_end[];
>>>>  
>>>>  extern void __kvm_flush_vm_context(void);
>>>>  extern void __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa);
>>>> +extern void __kvm_tlb_flush_vmid(struct kvm *kvm);
>>>>  
>>>>  extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu);
>>>>  #endif
>>>> diff --git a/arch/arm/kvm/interrupts.S b/arch/arm/kvm/interrupts.S
>>>> index 0d68d40..bddc66b 100644
>>>> --- a/arch/arm/kvm/interrupts.S
>>>> +++ b/arch/arm/kvm/interrupts.S
>>>> @@ -66,6 +66,17 @@ ENTRY(__kvm_tlb_flush_vmid_ipa)
>>>>  	bx	lr
>>>>  ENDPROC(__kvm_tlb_flush_vmid_ipa)
>>>>  
>>>> +/**
>>>> + * void __kvm_tlb_flush_vmid(struct kvm *kvm) - Flush per-VMID TLBs
>>>> + *
>>>> + * Reuses __kvm_tlb_flush_vmid_ipa() for ARMv7, without passing address
>>>> + * parameter
>>>> + */
>>>> +
>>>> +ENTRY(__kvm_tlb_flush_vmid)
>>>> +	b	__kvm_tlb_flush_vmid_ipa
>>>> +ENDPROC(__kvm_tlb_flush_vmid)
>>>> +
>>>>  /********************************************************************
>>>>   * Flush TLBs and instruction caches of all CPUs inside the inner-shareable
>>>>   * domain, for all VMIDs
>>>> diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
>>>> index 2ac9588..ef29540 100644
>>>> --- a/arch/arm/kvm/mmu.c
>>>> +++ b/arch/arm/kvm/mmu.c
>>>> @@ -56,6 +56,20 @@ static void kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)
>>>>  		kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, kvm, ipa);
>>>>  }
>>>>  
>>>> +/**
>>>> + * kvm_flush_remote_tlbs() - flush all VM TLB entries
>>>> + * @kvm:       pointer to kvm structure.
>>>> + *
>>>> + * Interface to HYP function to flush all VM TLB entries without address
>>>> + * parameter. In HYP mode reuses __kvm_tlb_flush_vmid_ipa() function used by
>>>> + * kvm_tlb_flush_vmid_ipa().
>>>> + */
>>>> +void kvm_flush_remote_tlbs(struct kvm *kvm)
>>>> +{
>>>> +	if (kvm)
>>>> +		kvm_call_hyp(__kvm_tlb_flush_vmid, kvm);
>>>> +}
>>>> +
>>>>  static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,
>>>>  				  int min, int max)
>>>>  {
>>>> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
>>>> index fa70c6e..ba25765 100644
>>>> --- a/virt/kvm/kvm_main.c
>>>> +++ b/virt/kvm/kvm_main.c
>>>> @@ -184,7 +184,7 @@ static bool make_all_cpus_request(struct kvm *kvm, unsigned int req)
>>>>  	return called;
>>>>  }
>>>>  
>>>> -void kvm_flush_remote_tlbs(struct kvm *kvm)
>>>> +void __weak kvm_flush_remote_tlbs(struct kvm *kvm)
>>>>  {
>>>>  	long dirty_count = kvm->tlbs_dirty;
>>>>  
>>>> -- 
>>>> 1.7.9.5
>>>>
>>>
>>> This doesn't build or link on aarch64 :(
>>>
>>> -Christoffer
>>>
>>
>> I'll recompile and retest the dirty page logging portion on ARMv8 and
>> resolve these issues, early next week.
>>
>> In the meantime if it's ok with you, I'' move forward with the
>> rest of the patches on ARMv7 to get through critical issues.
>>
>> Would that work?
> 
> Your patches need to at least compile with other architectures, I
> suggest fixing that up front.  You also eventually need to somehow test
> (or ask maintainers to test) a branch with your patches on the
> architectures that your code messes with.  This later point can be
> addressed once we're close to a consensus on ARM.

Ok got it. So far I just checked to make sure x86 compiles since
one function is generic and declared __weak, both x86 and ARM
share it now (Xiaos comment).
> 
> -Christoffer
>