KVM: arm64: selftests: Alias EL1 registers to EL2 counterparts

FEAT_VHE has the somewhat nice property of implicitly redirecting EL1
register aliases to their corresponding EL2 representations when E2H=1.
Unfortunately, there's no such abstraction for userspace and EL2
registers are always accessed by their canonical encoding.

Introduce a helper that applies EL2 redirections to sysregs and use
aggressive inlining to catch misuse at compile time. Go a little past
the architectural definition for ease of use for test authors (e.g. the
stack pointer).

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>

diff --git a/tools/testing/selftests/kvm/arm64/vpmu_counter_access.c b/tools/testing/selftests/kvm/arm64/vpmu_counter_access.c
index 4a7e8e85a1b84cdf0ab5888bdaf7cde6f27cf11e..36a3a8b4e0b563d729cdac68aa205209f3a02f1f 100644 (file)
--- a/tools/testing/selftests/kvm/arm64/vpmu_counter_access.c
+++ b/tools/testing/selftests/kvm/arm64/vpmu_counter_access.c
@@ -517,7 +517,7 @@ static void run_access_test(uint64_t pmcr_n)
        vcpu = vpmu_vm.vcpu;
 
        /* Save the initial sp to restore them later to run the guest again */
-       sp = vcpu_get_reg(vcpu, ARM64_CORE_REG(sp_el1));
+       sp = vcpu_get_reg(vcpu, ctxt_reg_alias(vcpu, SYS_SP_EL1));
 
        run_vcpu(vcpu, pmcr_n);
 
@@ -529,7 +529,7 @@ static void run_access_test(uint64_t pmcr_n)
        init.features[0] |= (1 << KVM_ARM_VCPU_PMU_V3);
        aarch64_vcpu_setup(vcpu, &init);
        vcpu_init_descriptor_tables(vcpu);
-       vcpu_set_reg(vcpu, ARM64_CORE_REG(sp_el1), sp);
+       vcpu_set_reg(vcpu, ctxt_reg_alias(vcpu, SYS_SP_EL1), sp);
        vcpu_set_reg(vcpu, ARM64_CORE_REG(regs.pc), (uint64_t)guest_code);
 
        run_vcpu(vcpu, pmcr_n);

diff --git a/tools/testing/selftests/kvm/include/arm64/processor.h b/tools/testing/selftests/kvm/include/arm64/processor.h
index 8c066ba1deb5bc51b4562145331ab1f528440ee7..5a4b29c1b9657cb248141f66dae1bbca00fb295d 100644 (file)
--- a/tools/testing/selftests/kvm/include/arm64/processor.h
+++ b/tools/testing/selftests/kvm/include/arm64/processor.h
@@ -303,4 +303,58 @@ void wfi(void);
 void test_wants_mte(void);
 void test_disable_default_vgic(void);
 
+static bool vcpu_has_el2(struct kvm_vcpu *vcpu)
+{
+       return vcpu->init.features[0] & BIT(KVM_ARM_VCPU_HAS_EL2);
+}
+
+#define MAPPED_EL2_SYSREG(el2, el1)            \
+       case SYS_##el1:                         \
+               if (vcpu_has_el2(vcpu))         \
+                       alias = SYS_##el2;      \
+               break
+
+
+static __always_inline u64 ctxt_reg_alias(struct kvm_vcpu *vcpu, u32 encoding)
+{
+       u32 alias = encoding;
+
+       BUILD_BUG_ON(!__builtin_constant_p(encoding));
+
+       switch (encoding) {
+       MAPPED_EL2_SYSREG(SCTLR_EL2,            SCTLR_EL1);
+       MAPPED_EL2_SYSREG(CPTR_EL2,             CPACR_EL1);
+       MAPPED_EL2_SYSREG(TTBR0_EL2,            TTBR0_EL1);
+       MAPPED_EL2_SYSREG(TTBR1_EL2,            TTBR1_EL1);
+       MAPPED_EL2_SYSREG(TCR_EL2,              TCR_EL1);
+       MAPPED_EL2_SYSREG(VBAR_EL2,             VBAR_EL1);
+       MAPPED_EL2_SYSREG(AFSR0_EL2,            AFSR0_EL1);
+       MAPPED_EL2_SYSREG(AFSR1_EL2,            AFSR1_EL1);
+       MAPPED_EL2_SYSREG(ESR_EL2,              ESR_EL1);
+       MAPPED_EL2_SYSREG(FAR_EL2,              FAR_EL1);
+       MAPPED_EL2_SYSREG(MAIR_EL2,             MAIR_EL1);
+       MAPPED_EL2_SYSREG(TCR2_EL2,             TCR2_EL1);
+       MAPPED_EL2_SYSREG(PIR_EL2,              PIR_EL1);
+       MAPPED_EL2_SYSREG(PIRE0_EL2,            PIRE0_EL1);
+       MAPPED_EL2_SYSREG(POR_EL2,              POR_EL1);
+       MAPPED_EL2_SYSREG(AMAIR_EL2,            AMAIR_EL1);
+       MAPPED_EL2_SYSREG(ELR_EL2,              ELR_EL1);
+       MAPPED_EL2_SYSREG(SPSR_EL2,             SPSR_EL1);
+       MAPPED_EL2_SYSREG(ZCR_EL2,              ZCR_EL1);
+       MAPPED_EL2_SYSREG(CONTEXTIDR_EL2,       CONTEXTIDR_EL1);
+       MAPPED_EL2_SYSREG(SCTLR2_EL2,           SCTLR2_EL1);
+       MAPPED_EL2_SYSREG(CNTHCTL_EL2,          CNTKCTL_EL1);
+       case SYS_SP_EL1:
+               if (!vcpu_has_el2(vcpu))
+                       return ARM64_CORE_REG(sp_el1);
+
+               alias = SYS_SP_EL2;
+               break;
+       default:
+               BUILD_BUG();
+       }
+
+       return KVM_ARM64_SYS_REG(alias);
+}
+
 #endif /* SELFTEST_KVM_PROCESSOR_H */

diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
index 3ab1fffbc3f286fb42ce6204c141b319bd7b12c0..11b6c5aa3f122f52d60bd712877017421934c618 100644 (file)
--- a/tools/testing/selftests/kvm/include/kvm_util.h
+++ b/tools/testing/selftests/kvm/include/kvm_util.h
@@ -63,6 +63,9 @@ struct kvm_vcpu {
        struct kvm_run *run;
 #ifdef __x86_64__
        struct kvm_cpuid2 *cpuid;
+#endif
+#ifdef __aarch64__
+       struct kvm_vcpu_init init;
 #endif
        struct kvm_binary_stats stats;
        struct kvm_dirty_gfn *dirty_gfns;

diff --git a/tools/testing/selftests/kvm/lib/arm64/processor.c b/tools/testing/selftests/kvm/lib/arm64/processor.c
index de77d9a7e0cd34ffe006e51e080d82bd3846cc5e..311660a9f655257f22506a6275d71a4c773367e6 100644 (file)
--- a/tools/testing/selftests/kvm/lib/arm64/processor.c
+++ b/tools/testing/selftests/kvm/lib/arm64/processor.c
@@ -283,15 +283,16 @@ void aarch64_vcpu_setup(struct kvm_vcpu *vcpu, struct kvm_vcpu_init *init)
        }
 
        vcpu_ioctl(vcpu, KVM_ARM_VCPU_INIT, init);
+       vcpu->init = *init;
 
        /*
         * Enable FP/ASIMD to avoid trapping when accessing Q0-Q15
         * registers, which the variable argument list macros do.
         */
-       vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_CPACR_EL1), 3 << 20);
+       vcpu_set_reg(vcpu, ctxt_reg_alias(vcpu, SYS_CPACR_EL1), 3 << 20);
 
-       sctlr_el1 = vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(SYS_SCTLR_EL1));
-       tcr_el1 = vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(SYS_TCR_EL1));
+       sctlr_el1 = vcpu_get_reg(vcpu, ctxt_reg_alias(vcpu, SYS_SCTLR_EL1));
+       tcr_el1 = vcpu_get_reg(vcpu, ctxt_reg_alias(vcpu, SYS_TCR_EL1));
 
        /* Configure base granule size */
        switch (vm->mode) {
@@ -358,10 +359,10 @@ void aarch64_vcpu_setup(struct kvm_vcpu *vcpu, struct kvm_vcpu_init *init)
        if (use_lpa2_pte_format(vm))
                tcr_el1 |= TCR_DS;
 
-       vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_SCTLR_EL1), sctlr_el1);
-       vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_TCR_EL1), tcr_el1);
-       vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_MAIR_EL1), DEFAULT_MAIR_EL1);
-       vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_TTBR0_EL1), ttbr0_el1);
+       vcpu_set_reg(vcpu, ctxt_reg_alias(vcpu, SYS_SCTLR_EL1), sctlr_el1);
+       vcpu_set_reg(vcpu, ctxt_reg_alias(vcpu, SYS_TCR_EL1), tcr_el1);
+       vcpu_set_reg(vcpu, ctxt_reg_alias(vcpu, SYS_MAIR_EL1), DEFAULT_MAIR_EL1);
+       vcpu_set_reg(vcpu, ctxt_reg_alias(vcpu, SYS_TTBR0_EL1), ttbr0_el1);
        vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_TPIDR_EL1), vcpu->id);
 }
 
@@ -396,7 +397,7 @@ static struct kvm_vcpu *__aarch64_vcpu_add(struct kvm_vm *vm, uint32_t vcpu_id,
 
        aarch64_vcpu_setup(vcpu, init);
 
-       vcpu_set_reg(vcpu, ARM64_CORE_REG(sp_el1), stack_vaddr + stack_size);
+       vcpu_set_reg(vcpu, ctxt_reg_alias(vcpu, SYS_SP_EL1), stack_vaddr + stack_size);
        return vcpu;
 }
 
@@ -466,7 +467,7 @@ void vcpu_init_descriptor_tables(struct kvm_vcpu *vcpu)
 {
        extern char vectors;
 
-       vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_VBAR_EL1), (uint64_t)&vectors);
+       vcpu_set_reg(vcpu, ctxt_reg_alias(vcpu, SYS_VBAR_EL1), (uint64_t)&vectors);
 }
 
 void route_exception(struct ex_regs *regs, int vector)