Commit 29d1697c authored by Marc Zyngier's avatar Marc Zyngier
Browse files

KVM: arm64: Document NV caps and vcpu flags 



Describe the two new vcpu flags that control NV, together with
the capabilities that advertise them.

Reviewed-by: default avatarOliver Upton <oliver.upton@linux.dev>
Reviewed-by: default avatarJoey Gouly <joey.gouly@arm.com>
Link: https://lore.kernel.org/r/20250514103501.2225951-18-maz@kernel.org


Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
parent a7484c80

Documentation/virt/kvm/api.rst

+13 −1
Original line number Diff line number Diff line
@@ -3460,7 +3460,8 @@ The initial values are defined as: 
	- FPSIMD/NEON registers: set to 0

	- SVE registers: set to 0

	- System registers: Reset to their architecturally defined

	  values as for a warm reset to EL1 (resp. SVC)

	  values as for a warm reset to EL1 (resp. SVC) or EL2 (in the

	  case of EL2 being enabled).



Note that because some registers reflect machine topology, all vcpus

should be created before this ioctl is invoked.
@@ -3527,6 +3528,17 @@ Possible features: 
	      - the KVM_REG_ARM64_SVE_VLS pseudo-register is immutable, and can

	        no longer be written using KVM_SET_ONE_REG.



	- KVM_ARM_VCPU_HAS_EL2: Enable Nested Virtualisation support,

	  booting the guest from EL2 instead of EL1.

	  Depends on KVM_CAP_ARM_EL2.

	  The VM is running with HCR_EL2.E2H being RES1 (VHE) unless

	  KVM_ARM_VCPU_HAS_EL2_E2H0 is also set.



	- KVM_ARM_VCPU_HAS_EL2_E2H0: Restrict Nested Virtualisation

	  support to HCR_EL2.E2H being RES0 (non-VHE).

	  Depends on KVM_CAP_ARM_EL2_E2H0.

	  KVM_ARM_VCPU_HAS_EL2 must also be set.



4.83 KVM_ARM_PREFERRED_TARGET

-----------------------------