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authorMarc Zyngier <maz@kernel.org>2025-05-23 10:58:15 +0100
committerMarc Zyngier <maz@kernel.org>2025-05-23 10:58:15 +0100
commitfef3acf5ae801109119c07568677d8acfd16ccda (patch)
treeb1ad35a3280d8cce33ce226f4c75b27e7409c7b1 /arch/arm64/kvm/handle_exit.c
parent6eb0ed96293f7c2d5e0b170698169a04f7d95d1a (diff)
parent98dbe56a016a4ea457ef312637a625d3c627dbd9 (diff)
Merge branch kvm-arm64/fgt-masks into kvmarm-master/next
* kvm-arm64/fgt-masks: (43 commits) : . : Large rework of the way KVM deals with trap bits in conjunction with : the CPU feature registers. It now draws a direct link between which : the feature set, the system registers that need to UNDEF to match : the configuration and bits that need to behave as RES0 or RES1 in : the trap registers that are visible to the guest. : : Best of all, these definitions are mostly automatically generated : from the JSON description published by ARM under a permissive : license. : . KVM: arm64: Handle TSB CSYNC traps KVM: arm64: Add FGT descriptors for FEAT_FGT2 KVM: arm64: Allow sysreg ranges for FGT descriptors KVM: arm64: Add context-switch for FEAT_FGT2 registers KVM: arm64: Add trap routing for FEAT_FGT2 registers KVM: arm64: Add sanitisation for FEAT_FGT2 registers KVM: arm64: Add FEAT_FGT2 registers to the VNCR page KVM: arm64: Use HCR_EL2 feature map to drive fixed-value bits KVM: arm64: Use HCRX_EL2 feature map to drive fixed-value bits KVM: arm64: Allow kvm_has_feat() to take variable arguments KVM: arm64: Use FGT feature maps to drive RES0 bits KVM: arm64: Validate FGT register descriptions against RES0 masks KVM: arm64: Switch to table-driven FGU configuration KVM: arm64: Handle PSB CSYNC traps KVM: arm64: Use KVM-specific HCRX_EL2 RES0 mask KVM: arm64: Remove hand-crafted masks for FGT registers KVM: arm64: Use computed FGT masks to setup FGT registers KVM: arm64: Propagate FGT masks to the nVHE hypervisor KVM: arm64: Unconditionally configure fine-grain traps KVM: arm64: Use computed masks as sanitisers for FGT registers ... Signed-off-by: Marc Zyngier <maz@kernel.org>
Diffstat (limited to 'arch/arm64/kvm/handle_exit.c')
-rw-r--r--arch/arm64/kvm/handle_exit.c77
1 files changed, 77 insertions, 0 deletions
diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c
index 5c49540883e3..7771ceced994 100644
--- a/arch/arm64/kvm/handle_exit.c
+++ b/arch/arm64/kvm/handle_exit.c
@@ -299,6 +299,81 @@ static int handle_svc(struct kvm_vcpu *vcpu)
return 1;
}
+static int kvm_handle_gcs(struct kvm_vcpu *vcpu)
+{
+ /* We don't expect GCS, so treat it with contempt */
+ if (kvm_has_feat(vcpu->kvm, ID_AA64PFR1_EL1, GCS, IMP))
+ WARN_ON_ONCE(1);
+
+ kvm_inject_undefined(vcpu);
+ return 1;
+}
+
+static int handle_other(struct kvm_vcpu *vcpu)
+{
+ bool is_l2 = vcpu_has_nv(vcpu) && !is_hyp_ctxt(vcpu);
+ u64 hcrx = __vcpu_sys_reg(vcpu, HCRX_EL2);
+ u64 esr = kvm_vcpu_get_esr(vcpu);
+ u64 iss = ESR_ELx_ISS(esr);
+ struct kvm *kvm = vcpu->kvm;
+ bool allowed, fwd = false;
+
+ /*
+ * We only trap for two reasons:
+ *
+ * - the feature is disabled, and the only outcome is to
+ * generate an UNDEF.
+ *
+ * - the feature is enabled, but a NV guest wants to trap the
+ * feature used by its L2 guest. We forward the exception in
+ * this case.
+ *
+ * What we don't expect is to end-up here if the guest is
+ * expected be be able to directly use the feature, hence the
+ * WARN_ON below.
+ */
+ switch (iss) {
+ case ESR_ELx_ISS_OTHER_ST64BV:
+ allowed = kvm_has_feat(kvm, ID_AA64ISAR1_EL1, LS64, LS64_V);
+ if (is_l2)
+ fwd = !(hcrx & HCRX_EL2_EnASR);
+ break;
+ case ESR_ELx_ISS_OTHER_ST64BV0:
+ allowed = kvm_has_feat(kvm, ID_AA64ISAR1_EL1, LS64, LS64_ACCDATA);
+ if (is_l2)
+ fwd = !(hcrx & HCRX_EL2_EnAS0);
+ break;
+ case ESR_ELx_ISS_OTHER_LDST64B:
+ allowed = kvm_has_feat(kvm, ID_AA64ISAR1_EL1, LS64, LS64);
+ if (is_l2)
+ fwd = !(hcrx & HCRX_EL2_EnALS);
+ break;
+ case ESR_ELx_ISS_OTHER_TSBCSYNC:
+ allowed = kvm_has_feat(kvm, ID_AA64DFR0_EL1, TraceBuffer, TRBE_V1P1);
+ if (is_l2)
+ fwd = (__vcpu_sys_reg(vcpu, HFGITR2_EL2) & HFGITR2_EL2_TSBCSYNC);
+ break;
+ case ESR_ELx_ISS_OTHER_PSBCSYNC:
+ allowed = kvm_has_feat(kvm, ID_AA64DFR0_EL1, PMSVer, V1P5);
+ if (is_l2)
+ fwd = (__vcpu_sys_reg(vcpu, HFGITR_EL2) & HFGITR_EL2_PSBCSYNC);
+ break;
+ default:
+ /* Clearly, we're missing something. */
+ WARN_ON_ONCE(1);
+ allowed = false;
+ }
+
+ WARN_ON_ONCE(allowed && !fwd);
+
+ if (allowed && fwd)
+ kvm_inject_nested_sync(vcpu, esr);
+ else
+ kvm_inject_undefined(vcpu);
+
+ return 1;
+}
+
static exit_handle_fn arm_exit_handlers[] = {
[0 ... ESR_ELx_EC_MAX] = kvm_handle_unknown_ec,
[ESR_ELx_EC_WFx] = kvm_handle_wfx,
@@ -308,6 +383,7 @@ static exit_handle_fn arm_exit_handlers[] = {
[ESR_ELx_EC_CP14_LS] = kvm_handle_cp14_load_store,
[ESR_ELx_EC_CP10_ID] = kvm_handle_cp10_id,
[ESR_ELx_EC_CP14_64] = kvm_handle_cp14_64,
+ [ESR_ELx_EC_OTHER] = handle_other,
[ESR_ELx_EC_HVC32] = handle_hvc,
[ESR_ELx_EC_SMC32] = handle_smc,
[ESR_ELx_EC_HVC64] = handle_hvc,
@@ -325,6 +401,7 @@ static exit_handle_fn arm_exit_handlers[] = {
[ESR_ELx_EC_BRK64] = kvm_handle_guest_debug,
[ESR_ELx_EC_FP_ASIMD] = kvm_handle_fpasimd,
[ESR_ELx_EC_PAC] = kvm_handle_ptrauth,
+ [ESR_ELx_EC_GCS] = kvm_handle_gcs,
};
static exit_handle_fn kvm_get_exit_handler(struct kvm_vcpu *vcpu)