Merge branch kvm-arm64/vgic-sre-traps into kvmarm-master/next

* kvm-arm64/vgic-sre-traps:
  : .
  : Fix the multiple of cases where KVM/arm64 doesn't correctly
  : handle the guest trying to use a GICv3 that isn't advertised.
  :
  : From the cover letter:
  :
  : "It recently appeared that, when running on a GICv3-equipped platform
  : (which is what non-ancient arm64 HW has), *not* configuring a GICv3
  : for the guest could result in less than desirable outcomes.
  :
  : We have multiple issues to fix:
  :
  : - for registers that *always* trap (the SGI registers) or that *may*
  :   trap (the SRE register), we need to check whether a GICv3 has been
  :   instantiated before acting upon the trap.
  :
  : - for registers that only conditionally trap, we must actively trap
  :   them even in the absence of a GICv3 being instantiated, and handle
  :   those traps accordingly.
  :
  : - finally, ID registers must reflect the absence of a GICv3, so that
  :   we are consistent.
  :
  : This series goes through all these requirements. The main complexity
  : here is to apply a GICv3 configuration on the host in the absence of a
  : GICv3 in the guest. This is pretty hackish, but I don't have a much
  : better solution so far.
  :
  : As part of making wider use of of the trap bits, we fully define the
  : trap routing as per the architecture, something that we eventually
  : need for NV anyway."
  : .
  KVM: arm64: selftests: Cope with lack of GICv3 in set_id_regs
  KVM: arm64: Add selftest checking how the absence of GICv3 is handled
  KVM: arm64: Unify UNDEF injection helpers
  KVM: arm64: Make most GICv3 accesses UNDEF if they trap
  KVM: arm64: Honor guest requested traps in GICv3 emulation
  KVM: arm64: Add trap routing information for ICH_HCR_EL2
  KVM: arm64: Add ICH_HCR_EL2 to the vcpu state
  KVM: arm64: Zero ID_AA64PFR0_EL1.GIC when no GICv3 is presented to the guest
  KVM: arm64: Add helper for last ditch idreg adjustments
  KVM: arm64: Force GICv3 trap activation when no irqchip is configured on VHE
  KVM: arm64: Force SRE traps when SRE access is not enabled
  KVM: arm64: Move GICv3 trap configuration to kvm_calculate_traps()

Signed-off-by: Marc Zyngier <maz@kernel.org>

3 files changed, 177 insertions, 0 deletions

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..943d65fc6b0b
--- /dev/null
+++ b/tools/testing/selftests/kvm/aarch64/no-vgic-v3.c
@@ -0,0 +1,175 @@
+// 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)					\
+	({							\
+		uint64_t val;					\
+								\
+		handled = false;				\
+		dsb(sy);					\
+		val = read_sysreg_s(SYS_ ## r);			\
+		val;						\
+	})
+
+#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)
+
+static void guest_code(void)
+{
+	uint64_t val;
+
+	/*
+	 * 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. Engage in non-fatal accesses, starting with a
+	 * write of 0 to try and disable SRE, and let's see if it
+	 * sticks.
+	 */
+	__check_sr_write(ICC_SRE_EL1);
+	if (!handled)
+		GUEST_PRINTF("ICC_SRE_EL1 write not trapping (OK)\n");
+
+	val = __check_sr_read(ICC_SRE_EL1);
+	if (!handled) {
+		__GUEST_ASSERT((val & BIT(0)),
+			       "ICC_SRE_EL1 not trapped but ICC_SRE_EL1.SRE not set\n");
+		GUEST_PRINTF("ICC_SRE_EL1 read not trapping (OK)\n");
+	}
+
+	GUEST_DONE();
+}
+
+static void guest_undef_handler(struct ex_regs *regs)
+{
+	/* Success, we've gracefully exploded! */
+	handled = true;
+	regs->pc += 4;
+}
+
+static void test_run_vcpu(struct kvm_vcpu *vcpu)
+{
+	struct ucall uc;
+
+	do {
+		vcpu_run(vcpu);
+
+		switch (get_ucall(vcpu, &uc)) {
+		case UCALL_ABORT:
+			REPORT_GUEST_ASSERT(uc);
+			break;
+		case UCALL_PRINTF:
+			printf("%s", uc.buffer);
+			break;
+		case UCALL_DONE:
+			break;
+		default:
+			TEST_FAIL("Unknown ucall %lu", uc.cmd);
+		}
+	} while (uc.cmd != UCALL_DONE);
+}
+
+static void test_guest_no_gicv3(void)
+{
+	struct kvm_vcpu *vcpu;
+	struct kvm_vm *vm;
+
+	/* 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);
+
+	test_run_vcpu(vcpu);
+
+	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;
+}
diff --git a/tools/testing/selftests/kvm/aarch64/set_id_regs.c b/tools/testing/selftests/kvm/aarch64/set_id_regs.c
index d20981663831..2a3fe7914b72 100644
--- a/tools/testing/selftests/kvm/aarch64/set_id_regs.c
+++ b/tools/testing/selftests/kvm/aarch64/set_id_regs.c
@@ -126,6 +126,7 @@ static const struct reg_ftr_bits ftr_id_aa64pfr0_el1[] = {
 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64PFR0_EL1, CSV2, 0),
 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64PFR0_EL1, DIT, 0),
 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64PFR0_EL1, SEL2, 0),
+	REG_FTR_BITS(FTR_EXACT, ID_AA64PFR0_EL1, GIC, 0),
 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64PFR0_EL1, EL3, 0),
 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64PFR0_EL1, EL2, 0),
 	REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64PFR0_EL1, EL1, 0),