diff mbox series

[12/12] KVM: arm64: Add selftest checking how the absence of GICv3 is handled

Message ID 20240820100349.3544850-13-maz@kernel.org (mailing list archive)
State New, archived
Headers show
Series KVM: arm64: Handle the lack of GICv3 exposed to a guest | expand

Commit Message

Marc Zyngier Aug. 20, 2024, 10:03 a.m. UTC 
Given how tortuous and fragile the whole lack-of-GICv3 story is,
add a selftest checking that we don't regress it.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 tools/testing/selftests/kvm/Makefile          |   1 +
 .../selftests/kvm/aarch64/no-vgic-v3.c        | 170 ++++++++++++++++++
 2 files changed, 171 insertions(+)
 create mode 100644 tools/testing/selftests/kvm/aarch64/no-vgic-v3.c

Comments

Oliver Upton Aug. 21, 2024, 12:10 a.m. UTC | #1 
On Tue, Aug 20, 2024 at 11:03:49AM +0100, Marc Zyngier wrote:
> Given how tortuous and fragile the whole lack-of-GICv3 story is,
> add a selftest checking that we don't regress it.
> 
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
>  tools/testing/selftests/kvm/Makefile          |   1 +
>  .../selftests/kvm/aarch64/no-vgic-v3.c        | 170 ++++++++++++++++++
>  2 files changed, 171 insertions(+)
>  create mode 100644 tools/testing/selftests/kvm/aarch64/no-vgic-v3.c
> 
> diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
> index 48d32c5aa3eb..f66b37acc0b0 100644
> --- a/tools/testing/selftests/kvm/Makefile
> +++ b/tools/testing/selftests/kvm/Makefile
> @@ -163,6 +163,7 @@ TEST_GEN_PROGS_aarch64 += aarch64/vgic_init
>  TEST_GEN_PROGS_aarch64 += aarch64/vgic_irq
>  TEST_GEN_PROGS_aarch64 += aarch64/vgic_lpi_stress
>  TEST_GEN_PROGS_aarch64 += aarch64/vpmu_counter_access
> +TEST_GEN_PROGS_aarch64 += aarch64/no-vgic-v3
>  TEST_GEN_PROGS_aarch64 += access_tracking_perf_test
>  TEST_GEN_PROGS_aarch64 += arch_timer
>  TEST_GEN_PROGS_aarch64 += demand_paging_test
> diff --git a/tools/testing/selftests/kvm/aarch64/no-vgic-v3.c b/tools/testing/selftests/kvm/aarch64/no-vgic-v3.c
> new file mode 100644
> index 000000000000..27169afc94c6
> --- /dev/null
> +++ b/tools/testing/selftests/kvm/aarch64/no-vgic-v3.c
> @@ -0,0 +1,170 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +// Check that, on a GICv3 system, not configuring GICv3 correctly
> +// results in all of the sysregs generating an UNDEF exception.
> +
> +#include <test_util.h>
> +#include <kvm_util.h>
> +#include <processor.h>
> +
> +static volatile bool handled;
> +
> +#define __check_sr_read(r)					\
> +	do {							\
> +		uint64_t val;					\
> +								\
> +		handled = false;				\
> +		dsb(sy);					\
> +		val = read_sysreg_s(SYS_ ## r);			\
> +		(void)val;					\
> +	} while(0)
> +
> +#define __check_sr_write(r)					\
> +	do {							\
> +		handled = false;				\
> +		dsb(sy);					\
> +		write_sysreg_s(0, SYS_ ## r);			\
> +		isb();						\
> +	} while(0)
> +
> +/* Fatal checks */
> +#define check_sr_read(r)					\
> +	do {							\
> +		__check_sr_read(r);				\
> +		__GUEST_ASSERT(handled, #r " no read trap");	\
> +	} while(0)
> +
> +#define check_sr_write(r)					\
> +	do {							\
> +		__check_sr_write(r);				\
> +		__GUEST_ASSERT(handled, #r " no write trap");	\
> +	} while(0)
> +
> +#define check_sr_rw(r)				\
> +	do {					\
> +		check_sr_read(r);		\
> +		check_sr_write(r);		\
> +	} while(0)
> +
> +/* Non-fatal checks */
> +#define check_sr_read_maybe(r)						\
> +	do {								\
> +		__check_sr_read(r);					\
> +		if (!handled)						\
> +			GUEST_PRINTF(#r " read not trapping (OK)\n");	\
> +	} while(0)
> +
> +#define check_sr_write_maybe(r)						\
> +	do {								\
> +		__check_sr_write(r);					\
> +		if (!handled)						\
> +			GUEST_PRINTF(#r " write not trapping (OK)\n");	\
> +	} while(0)
> +
> +static void guest_code(void)
> +{
> +	/*
> +	 * Check that we advertise that ID_AA64PFR0_EL1.GIC == 0, having
> +	 * hidden the feature at runtime without any other userspace action.
> +	 */
> +	__GUEST_ASSERT(FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_GIC),
> +				 read_sysreg(id_aa64pfr0_el1)) == 0,
> +		       "GICv3 wrongly advertised");
> +
> +	/*
> +	 * Access all GICv3 registers, and fail if we don't get an UNDEF.
> +	 * Note that we happily access all the APxRn registers without
> +	 * checking their existance, as all we want to see is a failure.
> +	 */
> +	check_sr_rw(ICC_PMR_EL1);
> +	check_sr_read(ICC_IAR0_EL1);
> +	check_sr_write(ICC_EOIR0_EL1);
> +	check_sr_rw(ICC_HPPIR0_EL1);
> +	check_sr_rw(ICC_BPR0_EL1);
> +	check_sr_rw(ICC_AP0R0_EL1);
> +	check_sr_rw(ICC_AP0R1_EL1);
> +	check_sr_rw(ICC_AP0R2_EL1);
> +	check_sr_rw(ICC_AP0R3_EL1);
> +	check_sr_rw(ICC_AP1R0_EL1);
> +	check_sr_rw(ICC_AP1R1_EL1);
> +	check_sr_rw(ICC_AP1R2_EL1);
> +	check_sr_rw(ICC_AP1R3_EL1);
> +	check_sr_write(ICC_DIR_EL1);
> +	check_sr_read(ICC_RPR_EL1);
> +	check_sr_write(ICC_SGI1R_EL1);
> +	check_sr_write(ICC_ASGI1R_EL1);
> +	check_sr_write(ICC_SGI0R_EL1);
> +	check_sr_read(ICC_IAR1_EL1);
> +	check_sr_write(ICC_EOIR1_EL1);
> +	check_sr_rw(ICC_HPPIR1_EL1);
> +	check_sr_rw(ICC_BPR1_EL1);
> +	check_sr_rw(ICC_CTLR_EL1);
> +	check_sr_rw(ICC_IGRPEN0_EL1);
> +	check_sr_rw(ICC_IGRPEN1_EL1);
> +
> +	/*
> +	 * ICC_SRE_EL1 may not be trappable, as ICC_SRE_EL2.Enable can
> +	 * be RAO/WI
> +	 */
> +	check_sr_read_maybe(ICC_SRE_EL1);
> +	check_sr_write_maybe(ICC_SRE_EL1);

In the case that a write does not UNDEF, should we check that
ICC_SRE_EL1.SRE is also RAO/WI?
Marc Zyngier Aug. 21, 2024, 11:17 a.m. UTC | #2 
On Wed, 21 Aug 2024 01:10:23 +0100,
Oliver Upton <oliver.upton@linux.dev> wrote:
> 
> On Tue, Aug 20, 2024 at 11:03:49AM +0100, Marc Zyngier wrote:
> > Given how tortuous and fragile the whole lack-of-GICv3 story is,
> > add a selftest checking that we don't regress it.
> > 
> > Signed-off-by: Marc Zyngier <maz@kernel.org>
> > ---
> >  tools/testing/selftests/kvm/Makefile          |   1 +
> >  .../selftests/kvm/aarch64/no-vgic-v3.c        | 170 ++++++++++++++++++
> >  2 files changed, 171 insertions(+)
> >  create mode 100644 tools/testing/selftests/kvm/aarch64/no-vgic-v3.c
> > 
> > diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
> > index 48d32c5aa3eb..f66b37acc0b0 100644
> > --- a/tools/testing/selftests/kvm/Makefile
> > +++ b/tools/testing/selftests/kvm/Makefile
> > @@ -163,6 +163,7 @@ TEST_GEN_PROGS_aarch64 += aarch64/vgic_init
> >  TEST_GEN_PROGS_aarch64 += aarch64/vgic_irq
> >  TEST_GEN_PROGS_aarch64 += aarch64/vgic_lpi_stress
> >  TEST_GEN_PROGS_aarch64 += aarch64/vpmu_counter_access
> > +TEST_GEN_PROGS_aarch64 += aarch64/no-vgic-v3
> >  TEST_GEN_PROGS_aarch64 += access_tracking_perf_test
> >  TEST_GEN_PROGS_aarch64 += arch_timer
> >  TEST_GEN_PROGS_aarch64 += demand_paging_test
> > diff --git a/tools/testing/selftests/kvm/aarch64/no-vgic-v3.c b/tools/testing/selftests/kvm/aarch64/no-vgic-v3.c
> > new file mode 100644
> > index 000000000000..27169afc94c6
> > --- /dev/null
> > +++ b/tools/testing/selftests/kvm/aarch64/no-vgic-v3.c
> > @@ -0,0 +1,170 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +
> > +// Check that, on a GICv3 system, not configuring GICv3 correctly
> > +// results in all of the sysregs generating an UNDEF exception.
> > +
> > +#include <test_util.h>
> > +#include <kvm_util.h>
> > +#include <processor.h>
> > +
> > +static volatile bool handled;
> > +
> > +#define __check_sr_read(r)					\
> > +	do {							\
> > +		uint64_t val;					\
> > +								\
> > +		handled = false;				\
> > +		dsb(sy);					\
> > +		val = read_sysreg_s(SYS_ ## r);			\
> > +		(void)val;					\
> > +	} while(0)
> > +
> > +#define __check_sr_write(r)					\
> > +	do {							\
> > +		handled = false;				\
> > +		dsb(sy);					\
> > +		write_sysreg_s(0, SYS_ ## r);			\
> > +		isb();						\
> > +	} while(0)
> > +
> > +/* Fatal checks */
> > +#define check_sr_read(r)					\
> > +	do {							\
> > +		__check_sr_read(r);				\
> > +		__GUEST_ASSERT(handled, #r " no read trap");	\
> > +	} while(0)
> > +
> > +#define check_sr_write(r)					\
> > +	do {							\
> > +		__check_sr_write(r);				\
> > +		__GUEST_ASSERT(handled, #r " no write trap");	\
> > +	} while(0)
> > +
> > +#define check_sr_rw(r)				\
> > +	do {					\
> > +		check_sr_read(r);		\
> > +		check_sr_write(r);		\
> > +	} while(0)
> > +
> > +/* Non-fatal checks */
> > +#define check_sr_read_maybe(r)						\
> > +	do {								\
> > +		__check_sr_read(r);					\
> > +		if (!handled)						\
> > +			GUEST_PRINTF(#r " read not trapping (OK)\n");	\
> > +	} while(0)
> > +
> > +#define check_sr_write_maybe(r)						\
> > +	do {								\
> > +		__check_sr_write(r);					\
> > +		if (!handled)						\
> > +			GUEST_PRINTF(#r " write not trapping (OK)\n");	\
> > +	} while(0)
> > +
> > +static void guest_code(void)
> > +{
> > +	/*
> > +	 * Check that we advertise that ID_AA64PFR0_EL1.GIC == 0, having
> > +	 * hidden the feature at runtime without any other userspace action.
> > +	 */
> > +	__GUEST_ASSERT(FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_GIC),
> > +				 read_sysreg(id_aa64pfr0_el1)) == 0,
> > +		       "GICv3 wrongly advertised");
> > +
> > +	/*
> > +	 * Access all GICv3 registers, and fail if we don't get an UNDEF.
> > +	 * Note that we happily access all the APxRn registers without
> > +	 * checking their existance, as all we want to see is a failure.
> > +	 */
> > +	check_sr_rw(ICC_PMR_EL1);
> > +	check_sr_read(ICC_IAR0_EL1);
> > +	check_sr_write(ICC_EOIR0_EL1);
> > +	check_sr_rw(ICC_HPPIR0_EL1);
> > +	check_sr_rw(ICC_BPR0_EL1);
> > +	check_sr_rw(ICC_AP0R0_EL1);
> > +	check_sr_rw(ICC_AP0R1_EL1);
> > +	check_sr_rw(ICC_AP0R2_EL1);
> > +	check_sr_rw(ICC_AP0R3_EL1);
> > +	check_sr_rw(ICC_AP1R0_EL1);
> > +	check_sr_rw(ICC_AP1R1_EL1);
> > +	check_sr_rw(ICC_AP1R2_EL1);
> > +	check_sr_rw(ICC_AP1R3_EL1);
> > +	check_sr_write(ICC_DIR_EL1);
> > +	check_sr_read(ICC_RPR_EL1);
> > +	check_sr_write(ICC_SGI1R_EL1);
> > +	check_sr_write(ICC_ASGI1R_EL1);
> > +	check_sr_write(ICC_SGI0R_EL1);
> > +	check_sr_read(ICC_IAR1_EL1);
> > +	check_sr_write(ICC_EOIR1_EL1);
> > +	check_sr_rw(ICC_HPPIR1_EL1);
> > +	check_sr_rw(ICC_BPR1_EL1);
> > +	check_sr_rw(ICC_CTLR_EL1);
> > +	check_sr_rw(ICC_IGRPEN0_EL1);
> > +	check_sr_rw(ICC_IGRPEN1_EL1);
> > +
> > +	/*
> > +	 * ICC_SRE_EL1 may not be trappable, as ICC_SRE_EL2.Enable can
> > +	 * be RAO/WI
> > +	 */
> > +	check_sr_read_maybe(ICC_SRE_EL1);
> > +	check_sr_write_maybe(ICC_SRE_EL1);
> 
> In the case that a write does not UNDEF, should we check that
> ICC_SRE_EL1.SRE is also RAO/WI?

Ah, not a bad idea. I'll add that.

Thanks,

	M.
diff mbox series

Patch

diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 48d32c5aa3eb..f66b37acc0b0 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -163,6 +163,7 @@  TEST_GEN_PROGS_aarch64 += aarch64/vgic_init
 TEST_GEN_PROGS_aarch64 += aarch64/vgic_irq
 TEST_GEN_PROGS_aarch64 += aarch64/vgic_lpi_stress
 TEST_GEN_PROGS_aarch64 += aarch64/vpmu_counter_access
+TEST_GEN_PROGS_aarch64 += aarch64/no-vgic-v3
 TEST_GEN_PROGS_aarch64 += access_tracking_perf_test
 TEST_GEN_PROGS_aarch64 += arch_timer
 TEST_GEN_PROGS_aarch64 += demand_paging_test
diff --git a/tools/testing/selftests/kvm/aarch64/no-vgic-v3.c b/tools/testing/selftests/kvm/aarch64/no-vgic-v3.c
new file mode 100644
index 000000000000..27169afc94c6
--- /dev/null
+++ b/tools/testing/selftests/kvm/aarch64/no-vgic-v3.c
@@ -0,0 +1,170 @@ 
+// SPDX-License-Identifier: GPL-2.0
+
+// Check that, on a GICv3 system, not configuring GICv3 correctly
+// results in all of the sysregs generating an UNDEF exception.
+
+#include <test_util.h>
+#include <kvm_util.h>
+#include <processor.h>
+
+static volatile bool handled;
+
+#define __check_sr_read(r)					\
+	do {							\
+		uint64_t val;					\
+								\
+		handled = false;				\
+		dsb(sy);					\
+		val = read_sysreg_s(SYS_ ## r);			\
+		(void)val;					\
+	} while(0)
+
+#define __check_sr_write(r)					\
+	do {							\
+		handled = false;				\
+		dsb(sy);					\
+		write_sysreg_s(0, SYS_ ## r);			\
+		isb();						\
+	} while(0)
+
+/* Fatal checks */
+#define check_sr_read(r)					\
+	do {							\
+		__check_sr_read(r);				\
+		__GUEST_ASSERT(handled, #r " no read trap");	\
+	} while(0)
+
+#define check_sr_write(r)					\
+	do {							\
+		__check_sr_write(r);				\
+		__GUEST_ASSERT(handled, #r " no write trap");	\
+	} while(0)
+
+#define check_sr_rw(r)				\
+	do {					\
+		check_sr_read(r);		\
+		check_sr_write(r);		\
+	} while(0)
+
+/* Non-fatal checks */
+#define check_sr_read_maybe(r)						\
+	do {								\
+		__check_sr_read(r);					\
+		if (!handled)						\
+			GUEST_PRINTF(#r " read not trapping (OK)\n");	\
+	} while(0)
+
+#define check_sr_write_maybe(r)						\
+	do {								\
+		__check_sr_write(r);					\
+		if (!handled)						\
+			GUEST_PRINTF(#r " write not trapping (OK)\n");	\
+	} while(0)
+
+static void guest_code(void)
+{
+	/*
+	 * Check that we advertise that ID_AA64PFR0_EL1.GIC == 0, having
+	 * hidden the feature at runtime without any other userspace action.
+	 */
+	__GUEST_ASSERT(FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_GIC),
+				 read_sysreg(id_aa64pfr0_el1)) == 0,
+		       "GICv3 wrongly advertised");
+
+	/*
+	 * Access all GICv3 registers, and fail if we don't get an UNDEF.
+	 * Note that we happily access all the APxRn registers without
+	 * checking their existance, as all we want to see is a failure.
+	 */
+	check_sr_rw(ICC_PMR_EL1);
+	check_sr_read(ICC_IAR0_EL1);
+	check_sr_write(ICC_EOIR0_EL1);
+	check_sr_rw(ICC_HPPIR0_EL1);
+	check_sr_rw(ICC_BPR0_EL1);
+	check_sr_rw(ICC_AP0R0_EL1);
+	check_sr_rw(ICC_AP0R1_EL1);
+	check_sr_rw(ICC_AP0R2_EL1);
+	check_sr_rw(ICC_AP0R3_EL1);
+	check_sr_rw(ICC_AP1R0_EL1);
+	check_sr_rw(ICC_AP1R1_EL1);
+	check_sr_rw(ICC_AP1R2_EL1);
+	check_sr_rw(ICC_AP1R3_EL1);
+	check_sr_write(ICC_DIR_EL1);
+	check_sr_read(ICC_RPR_EL1);
+	check_sr_write(ICC_SGI1R_EL1);
+	check_sr_write(ICC_ASGI1R_EL1);
+	check_sr_write(ICC_SGI0R_EL1);
+	check_sr_read(ICC_IAR1_EL1);
+	check_sr_write(ICC_EOIR1_EL1);
+	check_sr_rw(ICC_HPPIR1_EL1);
+	check_sr_rw(ICC_BPR1_EL1);
+	check_sr_rw(ICC_CTLR_EL1);
+	check_sr_rw(ICC_IGRPEN0_EL1);
+	check_sr_rw(ICC_IGRPEN1_EL1);
+
+	/*
+	 * ICC_SRE_EL1 may not be trappable, as ICC_SRE_EL2.Enable can
+	 * be RAO/WI
+	 */
+	check_sr_read_maybe(ICC_SRE_EL1);
+	check_sr_write_maybe(ICC_SRE_EL1);
+
+	GUEST_DONE();
+}
+
+static void guest_undef_handler(struct ex_regs *regs)
+{
+	/* Success, we've gracefully exploded! */
+	handled = true;
+	regs->pc += 4;
+}
+
+static void test_guest_no_gicv3(void)
+{
+	struct kvm_vcpu *vcpu;
+	struct kvm_vm *vm;
+	struct ucall uc;
+
+	/* Create a VM without a GICv3 */
+	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
+
+	vm_init_descriptor_tables(vm);
+	vcpu_init_descriptor_tables(vcpu);
+
+	vm_install_sync_handler(vm, VECTOR_SYNC_CURRENT,
+				ESR_EC_UNKNOWN, guest_undef_handler);
+again:
+	vcpu_run(vcpu);
+
+	switch (get_ucall(vcpu, &uc)) {
+	case UCALL_ABORT:
+		REPORT_GUEST_ASSERT(uc);
+		break;
+	case UCALL_PRINTF:
+		printf("%s", uc.buffer);
+		goto again;
+	case UCALL_DONE:
+		break;
+	default:
+		TEST_FAIL("Unknown ucall %lu", uc.cmd);
+	}
+
+	kvm_vm_free(vm);
+}
+
+int main(int argc, char *argv[])
+{
+	struct kvm_vcpu *vcpu;
+	struct kvm_vm *vm;
+	uint64_t pfr0;
+
+	vm = vm_create_with_one_vcpu(&vcpu, NULL);
+	vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(SYS_ID_AA64PFR0_EL1), &pfr0);
+	__TEST_REQUIRE(FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_GIC), pfr0),
+		       "GICv3 not supported.");
+	kvm_vm_free(vm);
+
+	test_guest_no_gicv3();
+
+	return 0;
+}