Thread (18 messages) 18 messages, 2 authors, 2025-03-04
STALE511d LANDED
Revisions (4)
  1. v1 [diff vs current]
  2. v2 [diff vs current]
  3. v3 [diff vs current]
  4. v4 current

[PATCH v4 07/16] KVM: arm64: nv: Sanitise ICH_HCR_EL2 accesses

From: Marc Zyngier <maz@kernel.org>
Date: 2025-02-25 18:16:53
Also in: kvm, kvmarm
Subsystem: arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers: Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds

As ICH_HCR_EL2 is a VNCR accessor when runnintg NV, add some
sanitising to what gets written. Crucially, mark TDIR as RES0
if the HW doesn't support it (unlikely, but hey...), as well
as anything GICv4 related, since we only expose a GICv3 to the
uest.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/nested.c | 9 +++++++++
 1 file changed, 9 insertions(+)
diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c
index 0c9387d2f5070..7c8f39070a503 100644
--- a/arch/arm64/kvm/nested.c
+++ b/arch/arm64/kvm/nested.c
@@ -1290,6 +1290,15 @@ int kvm_init_nv_sysregs(struct kvm_vcpu *vcpu)
 		res0 |= GENMASK(11, 8);
 	set_sysreg_masks(kvm, CNTHCTL_EL2, res0, res1);
 
+	/* ICH_HCR_EL2 */
+	res0 = ICH_HCR_EL2_RES0;
+	res1 = ICH_HCR_EL2_RES1;
+	if (!(kvm_vgic_global_state.ich_vtr_el2 & ICH_VTR_EL2_TDS))
+		res0 |= ICH_HCR_EL2_TDIR;
+	/* No GICv4 is presented to the guest */
+	res0 |= ICH_HCR_EL2_DVIM | ICH_HCR_EL2_vSGIEOICount;
+	set_sysreg_masks(kvm, ICH_HCR_EL2, res0, res1);
+
 out:
 	for (enum vcpu_sysreg sr = __SANITISED_REG_START__; sr < NR_SYS_REGS; sr++)
 		(void)__vcpu_sys_reg(vcpu, sr);
-- 
2.39.2

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