Re: [PATCH v3 08/10] KVM: arm64: selftests: Add tests for GIC redist/cpuif partially above IPA range

From: Eric Auger <eric.auger@redhat.com>
To: Ricardo Koller <ricarkol@google.com>,
	kvm@vger.kernel.org, maz@kernel.org,
	kvmarm@lists.cs.columbia.edu, drjones@redhat.com,
	alexandru.elisei@arm.com
Cc: Paolo Bonzini <pbonzini@redhat.com>,
	oupton@google.com, james.morse@arm.com, suzuki.poulose@arm.com,
	shuah@kernel.org, jingzhangos@google.com, pshier@google.com,
	rananta@google.com, reijiw@google.com
Subject: Re: [PATCH v3 08/10] KVM: arm64: selftests: Add tests for GIC redist/cpuif partially above IPA range
Date: Thu, 30 Sep 2021 10:51:05 +0200	[thread overview]
Message-ID: <420f5eb6-4ed4-7c0b-266c-03b62a441b95@redhat.com> (raw)
In-Reply-To: <20210928184803.2496885-9-ricarkol@google.com>

Hi Ricardo,

On 9/28/21 8:48 PM, Ricardo Koller wrote:
> Add tests for checking that KVM returns the right error when trying to
> set GICv2 CPU interfaces or GICv3 Redistributors partially above the
> addressable IPA range. Also tighten the IPA range by replacing
> KVM_CAP_ARM_VM_IPA_SIZE with the IPA range currently configured for the
> guest (i.e., the default).
>
> The check for the GICv3 redistributor created using the REDIST legacy
> API is not sufficient as this new test only checks the check done using
> vcpus already created when setting the base. The next commit will add
> the missing test which verifies that the KVM check is done at first vcpu
> run.
>
> Signed-off-by: Ricardo Koller <ricarkol@google.com>
> ---
>  .../testing/selftests/kvm/aarch64/vgic_init.c | 46 ++++++++++++++-----
>  1 file changed, 35 insertions(+), 11 deletions(-)
>
> diff --git a/tools/testing/selftests/kvm/aarch64/vgic_init.c b/tools/testing/selftests/kvm/aarch64/vgic_init.c
> index 92f5c6ca6b8b..77a1941e61fa 100644
> --- a/tools/testing/selftests/kvm/aarch64/vgic_init.c
> +++ b/tools/testing/selftests/kvm/aarch64/vgic_init.c
> @@ -31,7 +31,7 @@ struct vm_gic {
>  	uint32_t gic_dev_type;
>  };
>  
> -static int max_ipa_bits;
> +static uint64_t max_phys_size;
>  
>  /* helper to access a redistributor register */
>  static int access_v3_redist_reg(int gicv3_fd, int vcpu, int offset,
> @@ -150,16 +150,21 @@ static void subtest_dist_rdist(struct vm_gic *v)
>  	TEST_ASSERT(ret && errno == EINVAL, "GIC redist/cpu base not aligned");
>  
>  	/* out of range address */
> -	if (max_ipa_bits) {
> -		addr = 1ULL << max_ipa_bits;
> -		ret = _kvm_device_access(v->gic_fd, KVM_DEV_ARM_VGIC_GRP_ADDR,
> -					 dist.attr, &addr, true);
> -		TEST_ASSERT(ret && errno == E2BIG, "dist address beyond IPA limit");
> +	addr = max_phys_size;
> +	ret = _kvm_device_access(v->gic_fd, KVM_DEV_ARM_VGIC_GRP_ADDR,
> +				 dist.attr, &addr, true);
> +	TEST_ASSERT(ret && errno == E2BIG, "dist address beyond IPA limit");
>  
> -		ret = _kvm_device_access(v->gic_fd, KVM_DEV_ARM_VGIC_GRP_ADDR,
> -					 rdist.attr, &addr, true);
> -		TEST_ASSERT(ret && errno == E2BIG, "redist address beyond IPA limit");
> -	}
> +	ret = _kvm_device_access(v->gic_fd, KVM_DEV_ARM_VGIC_GRP_ADDR,
> +				 rdist.attr, &addr, true);
> +	TEST_ASSERT(ret && errno == E2BIG, "redist address beyond IPA limit");
> +
> +	/* Space for half a rdist (a rdist is: 2 * rdist.alignment). */
> +	addr = max_phys_size - dist.alignment;
> +	ret = _kvm_device_access(v->gic_fd, KVM_DEV_ARM_VGIC_GRP_ADDR,
> +				 rdist.attr, &addr, true);
> +	TEST_ASSERT(ret && errno == E2BIG,
> +			"half of the redist is beyond IPA limit");
>  
>  	/* set REDIST base address @0x0*/
>  	addr = 0x00000;
> @@ -248,7 +253,21 @@ static void subtest_v3_redist_regions(struct vm_gic *v)
>  	kvm_device_access(v->gic_fd, KVM_DEV_ARM_VGIC_GRP_ADDR,
>  			  KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION, &addr, true);
>  
> -	addr = REDIST_REGION_ATTR_ADDR(1, 1ULL << max_ipa_bits, 0, 2);
> +	addr = REDIST_REGION_ATTR_ADDR(1, max_phys_size, 0, 2);
> +	ret = _kvm_device_access(v->gic_fd, KVM_DEV_ARM_VGIC_GRP_ADDR,
> +				 KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION, &addr, true);
> +	TEST_ASSERT(ret && errno == E2BIG,
> +		    "register redist region with base address beyond IPA range");
> +
> +	/* The last redist is above the pa range. */
> +	addr = REDIST_REGION_ATTR_ADDR(1, max_phys_size - 0x10000, 0, 2);
> +	ret = _kvm_device_access(v->gic_fd, KVM_DEV_ARM_VGIC_GRP_ADDR,
> +				 KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION, &addr, true);
> +	TEST_ASSERT(ret && errno == E2BIG,
> +		    "register redist region with base address beyond IPA range");
s/base address/top address
> +
> +	/* The last redist is above the pa range. */
> +	addr = REDIST_REGION_ATTR_ADDR(2, max_phys_size - 0x30000, 0, 2);
>  	ret = _kvm_device_access(v->gic_fd, KVM_DEV_ARM_VGIC_GRP_ADDR,
>  				 KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION, &addr, true);
Why this second check?
>  	TEST_ASSERT(ret && errno == E2BIG,
> @@ -608,8 +627,13 @@ void run_tests(uint32_t gic_dev_type)
>  int main(int ac, char **av)
>  {
>  	int ret;
> +	int max_ipa_bits, pa_bits;
>  
>  	max_ipa_bits = kvm_check_cap(KVM_CAP_ARM_VM_IPA_SIZE);
> +	pa_bits = vm_guest_mode_params[VM_MODE_DEFAULT].pa_bits;
> +	TEST_ASSERT(max_ipa_bits && pa_bits <= max_ipa_bits,
> +		"The default PA range should not be larger than the max.");
Isn't it already enforced in the test infra instead?
I see in lib/kvm_util.c

#ifdef __aarch64__
        if (vm->pa_bits != 40)
                vm->type = KVM_VM_TYPE_ARM_IPA_SIZE(vm->pa_bits);
#endif

vm_open()
> +	max_phys_size = 1ULL << pa_bits;
>  
>  	ret = test_kvm_device(KVM_DEV_TYPE_ARM_VGIC_V3);
>  	if (!ret) {
Eric