[PATCH v5 11/12] KVM: selftests: arm64: Determine max ipa size per-page size

[Ryan Roberts]

On 21/11/2023 23:27, Oliver Upton wrote:
> On Thu, Nov 16, 2023 at 02:29:30PM +0000, Ryan Roberts wrote:
>> We are about to add 52 bit PA guest modes for 4K and 16K pages when the
>> system supports LPA2. In preparation beef up the logic that parses mmfr0
>> to also tell us what the maximum supported PA size is for each page
>> size. Max PA size = 0 implies the page size is not supported at all.
>>
>> Signed-off-by: Ryan Roberts <ryan.roberts at arm.com>
>> ---
>>  .../selftests/kvm/include/aarch64/processor.h |  4 +-
>>  .../selftests/kvm/lib/aarch64/processor.c     | 27 ++++++++++---
>>  tools/testing/selftests/kvm/lib/guest_modes.c | 40 ++++++++-----------
>>  3 files changed, 41 insertions(+), 30 deletions(-)
>>
>> diff --git a/tools/testing/selftests/kvm/include/aarch64/processor.h b/tools/testing/selftests/kvm/include/aarch64/processor.h
>> index c42d683102c7..cf20e44e86f2 100644
>> --- a/tools/testing/selftests/kvm/include/aarch64/processor.h
>> +++ b/tools/testing/selftests/kvm/include/aarch64/processor.h
>> @@ -119,8 +119,8 @@ enum {
>>  /* Access flag update enable/disable */
>>  #define TCR_EL1_HA		(1ULL << 39)
>>  
>> -void aarch64_get_supported_page_sizes(uint32_t ipa,
>> -				      bool *ps4k, bool *ps16k, bool *ps64k);
>> +void aarch64_get_supported_page_sizes(uint32_t ipa, uint32_t *ipa4k,
>> +					uint32_t *ipa16k, uint32_t *ipa64k);
>>  
>>  void vm_init_descriptor_tables(struct kvm_vm *vm);
>>  void vcpu_init_descriptor_tables(struct kvm_vcpu *vcpu);
>> diff --git a/tools/testing/selftests/kvm/lib/aarch64/processor.c b/tools/testing/selftests/kvm/lib/aarch64/processor.c
>> index 6fe12e985ba5..917cfeddb6b4 100644
>> --- a/tools/testing/selftests/kvm/lib/aarch64/processor.c
>> +++ b/tools/testing/selftests/kvm/lib/aarch64/processor.c
>> @@ -492,12 +492,24 @@ uint32_t guest_get_vcpuid(void)
>>  	return read_sysreg(tpidr_el1);
>>  }
>>  
>> -void aarch64_get_supported_page_sizes(uint32_t ipa,
>> -				      bool *ps4k, bool *ps16k, bool *ps64k)
>> +static uint32_t max_ipa_for_page_size(uint32_t vm_ipa, uint32_t gran,
>> +				uint32_t not_sup_val, uint32_t ipa52_min_val)
>> +{
>> +	if (gran == not_sup_val)
>> +		return 0;
>> +	else if (gran >= ipa52_min_val && vm_ipa >= 52)
>> +		return 52;
>> +	else
>> +		return min(vm_ipa, 48U);
>> +}
>> +
>> +void aarch64_get_supported_page_sizes(uint32_t ipa, uint32_t *ipa4k,
>> +					uint32_t *ipa16k, uint32_t *ipa64k)
>>  {
>>  	struct kvm_vcpu_init preferred_init;
>>  	int kvm_fd, vm_fd, vcpu_fd, err;
>>  	uint64_t val;
>> +	uint32_t gran;
>>  	struct kvm_one_reg reg = {
>>  		.id	= KVM_ARM64_SYS_REG(SYS_ID_AA64MMFR0_EL1),
>>  		.addr	= (uint64_t)&val,
>> @@ -518,9 +530,14 @@ void aarch64_get_supported_page_sizes(uint32_t ipa,
>>  	err = ioctl(vcpu_fd, KVM_GET_ONE_REG, &reg);
>>  	TEST_ASSERT(err == 0, KVM_IOCTL_ERROR(KVM_GET_ONE_REG, vcpu_fd));
>>  
>> -	*ps4k = FIELD_GET(ARM64_FEATURE_MASK(ID_AA64MMFR0_EL1_TGRAN4), val) != 0xf;
>> -	*ps64k = FIELD_GET(ARM64_FEATURE_MASK(ID_AA64MMFR0_EL1_TGRAN64), val) == 0;
>> -	*ps16k = FIELD_GET(ARM64_FEATURE_MASK(ID_AA64MMFR0_EL1_TGRAN16), val) != 0;
>> +	gran = FIELD_GET(ARM64_FEATURE_MASK(ID_AA64MMFR0_EL1_TGRAN4), val);
>> +	*ipa4k = max_ipa_for_page_size(ipa, gran, 0xf, 1);
>> +
>> +	gran = FIELD_GET(ARM64_FEATURE_MASK(ID_AA64MMFR0_EL1_TGRAN64), val);
>> +	*ipa64k = max_ipa_for_page_size(ipa, gran, 0xf, 0);
>> +
>> +	gran = FIELD_GET(ARM64_FEATURE_MASK(ID_AA64MMFR0_EL1_TGRAN16), val);
>> +	*ipa16k = max_ipa_for_page_size(ipa, gran, 0, 2);
>>  
>>  	close(vcpu_fd);
>>  	close(vm_fd);
>> diff --git a/tools/testing/selftests/kvm/lib/guest_modes.c b/tools/testing/selftests/kvm/lib/guest_modes.c
>> index 1df3ce4b16fd..c64c5cf49942 100644
>> --- a/tools/testing/selftests/kvm/lib/guest_modes.c
>> +++ b/tools/testing/selftests/kvm/lib/guest_modes.c
>> @@ -18,33 +18,27 @@ void guest_modes_append_default(void)
>>  #else
>>  	{
>>  		unsigned int limit = kvm_check_cap(KVM_CAP_ARM_VM_IPA_SIZE);
>> -		bool ps4k, ps16k, ps64k;
>> +		uint32_t ipa4k, ipa16k, ipa64k;
>>  		int i;
>>  
>> -		aarch64_get_supported_page_sizes(limit, &ps4k, &ps16k, &ps64k);
>> +		aarch64_get_supported_page_sizes(limit, &ipa4k, &ipa16k, &ipa64k);
>>  
>> -		vm_mode_default = NUM_VM_MODES;
>> +		guest_mode_append(VM_MODE_P52V48_64K, ipa64k >= 52, ipa64k >= 52);
> 
> Can we just change guest_mode_append() to take a single bool argument and
> initialize both ::supported and ::enabled to its value?

Works for me; I'll fix it up and re-post next week.

>