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75b2fdc1a8
Implementations without FEAT_FGT aren't required to trap the entire ID register space when HCR_EL2.TID3 is set. This is a terrible idea, as the hypervisor may need to advertise the absence of a feature to the VM using a negative value in a signed field, FEAT_E2H0 being a great example of this. Cope with uncooperative implementations in the EL2 selftest by accepting a zero value when FEAT_FGT is absent and otherwise only tolerating the expected nonzero value. Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org>
72 lines
1.7 KiB
C
72 lines
1.7 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* hello_el2 - Basic KVM selftest for VM running at EL2 with E2H=RES1
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*
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* Copyright 2025 Google LLC
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*/
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#include "kvm_util.h"
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#include "processor.h"
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#include "test_util.h"
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#include "ucall.h"
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#include <asm/sysreg.h>
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static void guest_code(void)
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{
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u64 mmfr0 = read_sysreg_s(SYS_ID_AA64MMFR0_EL1);
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u64 mmfr1 = read_sysreg_s(SYS_ID_AA64MMFR1_EL1);
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u64 mmfr4 = read_sysreg_s(SYS_ID_AA64MMFR4_EL1);
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u8 e2h0 = SYS_FIELD_GET(ID_AA64MMFR4_EL1, E2H0, mmfr4);
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GUEST_ASSERT_EQ(get_current_el(), 2);
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GUEST_ASSERT(read_sysreg(hcr_el2) & HCR_EL2_E2H);
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GUEST_ASSERT_EQ(SYS_FIELD_GET(ID_AA64MMFR1_EL1, VH, mmfr1),
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ID_AA64MMFR1_EL1_VH_IMP);
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/*
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* Traps of the complete ID register space are IMPDEF without FEAT_FGT,
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* which is really annoying to deal with in KVM describing E2H as RES1.
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*
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* If the implementation doesn't honor the trap then expect the register
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* to return all zeros.
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*/
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if (e2h0 == ID_AA64MMFR4_EL1_E2H0_IMP)
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GUEST_ASSERT_EQ(SYS_FIELD_GET(ID_AA64MMFR0_EL1, FGT, mmfr0),
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ID_AA64MMFR0_EL1_FGT_NI);
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else
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GUEST_ASSERT_EQ(e2h0, ID_AA64MMFR4_EL1_E2H0_NI_NV1);
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GUEST_DONE();
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}
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int main(void)
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{
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struct kvm_vcpu_init init;
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struct kvm_vcpu *vcpu;
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struct kvm_vm *vm;
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struct ucall uc;
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TEST_REQUIRE(kvm_check_cap(KVM_CAP_ARM_EL2));
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vm = vm_create(1);
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kvm_get_default_vcpu_target(vm, &init);
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init.features[0] |= BIT(KVM_ARM_VCPU_HAS_EL2);
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vcpu = aarch64_vcpu_add(vm, 0, &init, guest_code);
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kvm_arch_vm_finalize_vcpus(vm);
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vcpu_run(vcpu);
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switch (get_ucall(vcpu, &uc)) {
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case UCALL_DONE:
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break;
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case UCALL_ABORT:
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REPORT_GUEST_ASSERT(uc);
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break;
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default:
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TEST_FAIL("Unhandled ucall: %ld\n", uc.cmd);
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}
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kvm_vm_free(vm);
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return 0;
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}
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