[PATCH 0/6] KVM: handling of MMIO pass-through regions

[Ard Biesheuvel]

On 29 September 2014 15:07, Christoffer Dall
<christoffer.dall at linaro.org> wrote:
> On Wed, Sep 17, 2014 at 02:56:15PM -0700, Ard Biesheuvel wrote:
>> This is a followup to the patches 'kvm: define PAGE_S2_DEVICE as
>> read-only by default' I sent out last week. Essentially build tested
>> only: while QEMU on KVM still works correctly for my use case with
>> these patches applied, it does not in fact use passthrough mappings
>> of device memory.
>>
>> Patch #1 is a trivial fix for an issue identified by sparse where we
>> are calling memset(0) on 2 MB worth of pages.
>>
>> Patch #2 fixes a potential NULL dereference in user_mem_abort()
>>
>> Patch #3 adds a 'writable' parameter to kmv_phys_addr_ioremap() so that
>> read-only device regions can be mapped using this function. The existing
>> callers are updated to pass 'true' for this parameter.
>>
>> Patch #4 and #5 were sent out before, and change the value of
>> PAGE_S2_DEVICE to read-only, so that read-only regions can be
>> ioremap()'ed
>>
>> Patch #6 ensures that VM_PFNMAP linear mappings of non-system RAM host
>> memory are mapped eagerly rather than faulted in page by page.
>>
>>
>> Ard Biesheuvel (6):
>>   arm/arm64: KVM: use __GFP_ZERO not memset() to get zeroed pages
>>   arm/arm64: KVM: fix potential NULL dereference in user_mem_abort()
>>   arm/arm64: KVM: add 'writable' parameter to kvm_phys_addr_ioremap
>>   ARM: kvm: define PAGE_S2_DEVICE as read-only by default
>>   arm64: kvm: define PAGE_S2_DEVICE as read-only by default
>>   arm/arm64: KVM: map MMIO regions at creation time
>>
>
> So I only had comments on that last one and the others are fairly benign
> and small patches, so assuming the arch maintainers don't complain about
> the mm header changes, I can queue the first 5 patches and add the last
> one when we sort that out.
>

Fine with me. Let's at least wait until we have the userland bits in
place to test this patch thoroughly.

-- 
Ard.