Commit 0cfc85b8 authored by Oliver Upton's avatar Oliver Upton
Browse files

KVM: arm64: nv: Load guest FP state for ZCR_EL2 trap 



Round out the ZCR_EL2 gymnastics by loading SVE state in the fast path
when the guest hypervisor tries to access SVE state.

Reviewed-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240620164653.1130714-11-oliver.upton@linux.dev


Signed-off-by: default avatarOliver Upton <oliver.upton@linux.dev>
parent 493da2b1

arch/arm64/kvm/hyp/include/hyp/switch.h

+4 −0
Original line number Diff line number Diff line
@@ -371,6 +371,10 @@ static bool kvm_hyp_handle_fpsimd(struct kvm_vcpu *vcpu, u64 *exit_code) 
		if (guest_hyp_fpsimd_traps_enabled(vcpu))

			return false;

		break;

	case ESR_ELx_EC_SYS64:

		if (WARN_ON_ONCE(!is_hyp_ctxt(vcpu)))

			return false;

		fallthrough;

	case ESR_ELx_EC_SVE:

		if (!sve_guest)

			return false;

arch/arm64/kvm/hyp/vhe/switch.c

+27 −0
Original line number Diff line number Diff line
@@ -288,11 +288,38 @@ static bool kvm_hyp_handle_cpacr_el1(struct kvm_vcpu *vcpu, u64 *exit_code) 
	return true;

}



static bool kvm_hyp_handle_zcr_el2(struct kvm_vcpu *vcpu, u64 *exit_code)

{

	u32 sysreg = esr_sys64_to_sysreg(kvm_vcpu_get_esr(vcpu));



	if (!vcpu_has_nv(vcpu))

		return false;



	if (sysreg != SYS_ZCR_EL2)

		return false;



	if (guest_owns_fp_regs())

		return false;



	/*

	 * ZCR_EL2 traps are handled in the slow path, with the expectation

	 * that the guest's FP context has already been loaded onto the CPU.

	 *

	 * Load the guest's FP context and unconditionally forward to the

	 * slow path for handling (i.e. return false).

	 */

	kvm_hyp_handle_fpsimd(vcpu, exit_code);

	return false;

}



static bool kvm_hyp_handle_sysreg_vhe(struct kvm_vcpu *vcpu, u64 *exit_code)

{

	if (kvm_hyp_handle_cpacr_el1(vcpu, exit_code))

		return true;



	if (kvm_hyp_handle_zcr_el2(vcpu, exit_code))

		return true;



	return kvm_hyp_handle_sysreg(vcpu, exit_code);

}