diff mbox series

[09/11] KVM: arm64: nv: Propagate CNTHCTL_EL2.EL1NV{P,V}CT bits

Message ID 20241202172134.384923-10-maz@kernel.org (mailing list archive)
State New
Headers show
Series KVM: arm64: Add NV timer support | expand

Commit Message

Marc Zyngier Dec. 2, 2024, 5:21 p.m. UTC 
Allow a guest hypervisor to trap accesses to CNT{P,V}CT_EL02 by
propagating these trap bits to the host trap configuration.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/arch_timer.c | 7 +++++++
 1 file changed, 7 insertions(+)
diff mbox series

Patch

diff --git a/arch/arm64/kvm/arch_timer.c b/arch/arm64/kvm/arch_timer.c
index 2c4499dd63732..f4607c4f68d2e 100644
--- a/arch/arm64/kvm/arch_timer.c
+++ b/arch/arm64/kvm/arch_timer.c
@@ -822,6 +822,10 @@  static void timer_set_traps(struct kvm_vcpu *vcpu, struct timer_map *map)
 	 * Apply the enable bits that the guest hypervisor has requested for
 	 * its own guest. We can only add traps that wouldn't have been set
 	 * above.
+	 * Implementation choices: we do not support NV when E2H=0 in the
+	 * guest, and we don't support configuration where E2H is writable
+	 * by the guest (either FEAT_VHE or FEAT_E2H0 is implemented, but
+	 * not both). This simplifies the handling of the EL1NV* bits.
 	 */
 	if (vcpu_has_nv(vcpu) && !is_hyp_ctxt(vcpu)) {
 		u64 val = __vcpu_sys_reg(vcpu, CNTHCTL_EL2);
@@ -832,6 +836,9 @@  static void timer_set_traps(struct kvm_vcpu *vcpu, struct timer_map *map)
 
 		tpt |= !(val & (CNTHCTL_EL1PCEN << 10));
 		tpc |= !(val & (CNTHCTL_EL1PCTEN << 10));
+
+		tpt02 |= (val & CNTHCTL_EL1NVPCT);
+		tvt02 |= (val & CNTHCTL_EL1NVVCT);
 	}
 
 	/*