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From: Christian Borntraeger <borntraeger@de.ibm.com>
To: Andrew Jones <drjones@redhat.com>, Thomas Huth <thuth@redhat.com>
Cc: "Janosch Frank" <frankja@linux.ibm.com>,
	kvm@vger.kernel.org, "Paolo Bonzini" <pbonzini@redhat.com>,
	"Radim Krčmář" <rkrcmar@redhat.com>,
	"Shuah Khan" <shuah@kernel.org>,
	"David Hildenbrand" <david@redhat.com>,
	"Cornelia Huck" <cohuck@redhat.com>,
	linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org,
	linux-s390@vger.kernel.org
Subject: Re:  Re: [PATCH 5/9] KVM: selftests: Align memory region addresses to 1M on s390x
Date: Fri, 24 May 2019 10:29:33 +0200	[thread overview]
Message-ID: <7919d65e-d814-9e68-4df0-d12f43f0b984@de.ibm.com> (raw)
In-Reply-To: <20190523174028.3giefzff3l5eclki@kamzik.brq.redhat.com>



On 23.05.19 19:40, Andrew Jones wrote:
> On Thu, May 23, 2019 at 06:43:05PM +0200, Thomas Huth wrote:
>> On s390x, there is a constraint that memory regions have to be aligned
>> to 1M (or running the VM will fail). Introduce a new "alignment" variable
>> in the vm_userspace_mem_region_add() function which now can be used for
>> both, huge page and s390x alignment requirements.
>>
>> Signed-off-by: Thomas Huth <thuth@redhat.com>
>> ---
>>  tools/testing/selftests/kvm/lib/kvm_util.c | 21 ++++++++++++++++-----
>>  1 file changed, 16 insertions(+), 5 deletions(-)
>>
>> diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
>> index 08edb8436c47..656df9d5cd4d 100644
>> --- a/tools/testing/selftests/kvm/lib/kvm_util.c
>> +++ b/tools/testing/selftests/kvm/lib/kvm_util.c
>> @@ -559,6 +559,7 @@ void vm_userspace_mem_region_add(struct kvm_vm *vm,
>>  	unsigned long pmem_size = 0;
>>  	struct userspace_mem_region *region;
>>  	size_t huge_page_size = KVM_UTIL_PGS_PER_HUGEPG * vm->page_size;
>> +	size_t alignment;
>>  
>>  	TEST_ASSERT((guest_paddr % vm->page_size) == 0, "Guest physical "
>>  		"address not on a page boundary.\n"
>> @@ -608,9 +609,20 @@ void vm_userspace_mem_region_add(struct kvm_vm *vm,
>>  	TEST_ASSERT(region != NULL, "Insufficient Memory");
>>  	region->mmap_size = npages * vm->page_size;
>>  
>> -	/* Enough memory to align up to a huge page. */
>> +#ifdef __s390x__
>> +	/* On s390x, the host address must be aligned to 1M (due to PGSTEs) */
>> +	alignment = 0x100000;
>> +#else
>> +	alignment = 1;
>> +#endif
>> +
>>  	if (src_type == VM_MEM_SRC_ANONYMOUS_THP)
>> -		region->mmap_size += huge_page_size;
>> +		alignment = huge_page_size;
> 
> I guess s390x won't ever support VM_MEM_SRC_ANONYMOUS_THP? If it does,
> then we need 'alignment = max(huge_page_size, alignment)'. Actually
> that might be a nice way to write this anyway for future-proofing.

I can do 
-		alignment = huge_page_size;
+		alignment = max(huge_page_size, alignment);

when applying.


> 
>> +
>> +	/* Add enough memory to align up if necessary */
>> +	if (alignment > 1)
>> +		region->mmap_size += alignment;
>> +
>>  	region->mmap_start = mmap(NULL, region->mmap_size,
>>  				  PROT_READ | PROT_WRITE,
>>  				  MAP_PRIVATE | MAP_ANONYMOUS
>> @@ -620,9 +632,8 @@ void vm_userspace_mem_region_add(struct kvm_vm *vm,
>>  		    "test_malloc failed, mmap_start: %p errno: %i",
>>  		    region->mmap_start, errno);
>>  
>> -	/* Align THP allocation up to start of a huge page. */
>> -	region->host_mem = align(region->mmap_start,
>> -				 src_type == VM_MEM_SRC_ANONYMOUS_THP ?  huge_page_size : 1);
>> +	/* Align host address */
>> +	region->host_mem = align(region->mmap_start, alignment);
>>  
>>  	/* As needed perform madvise */
>>  	if (src_type == VM_MEM_SRC_ANONYMOUS || src_type == VM_MEM_SRC_ANONYMOUS_THP) {
>> -- 
>> 2.21.0
>>
> 


  reply	other threads:[~2019-05-24  8:29 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-23 16:43 [PATCH v1 0/9] KVM selftests for s390x Thomas Huth
2019-05-23 16:43 ` [PATCH 1/9] KVM: selftests: Wrap vcpu_nested_state_get/set functions with x86 guard Thomas Huth
2019-05-23 16:43 ` [PATCH 2/9] KVM: selftests: Guard struct kvm_vcpu_events with __KVM_HAVE_VCPU_EVENTS Thomas Huth
2019-05-23 17:57   ` Andrew Jones
2019-05-23 16:43 ` [PATCH 3/9] kvm: selftests: aarch64: fix default vm mode Thomas Huth
2019-05-24  8:37   ` Christian Borntraeger
2019-05-23 16:43 ` [PATCH 4/9] KVM: selftests: Introduce a VM_MODE_DEFAULT macro for the default bits Thomas Huth
2019-05-23 17:20   ` Andrew Jones
2019-05-23 16:43 ` [PATCH 5/9] KVM: selftests: Align memory region addresses to 1M on s390x Thomas Huth
2019-05-23 17:40   ` Andrew Jones
2019-05-24  8:29     ` Christian Borntraeger [this message]
2019-05-24 18:17       ` Thomas Huth
2019-05-23 16:43 ` [PATCH 6/9] KVM: selftests: Add processor code for s390x Thomas Huth
2019-05-23 16:43 ` [PATCH 7/9] KVM: selftests: Add the sync_regs test " Thomas Huth
2019-05-23 16:43 ` [PATCH 8/9] KVM: s390: Do not report unusabled IDs via KVM_CAP_MAX_VCPU_ID Thomas Huth
2019-05-23 17:56   ` Andrew Jones
2019-05-24  9:13   ` Cornelia Huck
2019-05-24  9:16   ` David Hildenbrand
2019-05-28 11:00   ` Christian Borntraeger
2019-05-28 12:53     ` Cornelia Huck
2019-05-28 13:48       ` Christian Borntraeger
2019-05-23 16:43 ` [PATCH 9/9] KVM: selftests: Move kvm_create_max_vcpus test to generic code Thomas Huth
2019-05-23 17:56   ` Andrew Jones
2019-05-24  9:16   ` David Hildenbrand
2019-05-24 11:11 ` [PATCH v1 0/9] KVM selftests for s390x Christian Borntraeger
2019-05-24 12:17   ` Christian Borntraeger
2019-05-24 12:29     ` Christian Borntraeger
2019-05-24 12:36       ` David Hildenbrand
2019-05-24 12:56         ` Christian Borntraeger
2019-05-24 18:33 ` Christian Borntraeger
2019-06-04 17:19 ` Paolo Bonzini
2019-06-04 17:37   ` Christian Borntraeger

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