linux/include/kvm/arm_psci.h
Marc Zyngier 85bd0ba1ff arm/arm64: KVM: Add PSCI version selection API
Although we've implemented PSCI 0.1, 0.2 and 1.0, we expose either 0.1
or 1.0 to a guest, defaulting to the latest version of the PSCI
implementation that is compatible with the requested version. This is
no different from doing a firmware upgrade on KVM.

But in order to give a chance to hypothetical badly implemented guests
that would have a fit by discovering something other than PSCI 0.2,
let's provide a new API that allows userspace to pick one particular
version of the API.

This is implemented as a new class of "firmware" registers, where
we expose the PSCI version. This allows the PSCI version to be
save/restored as part of a guest migration, and also set to
any supported version if the guest requires it.

Cc: stable@vger.kernel.org #4.16
Reviewed-by: Christoffer Dall <cdall@kernel.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-04-20 16:32:23 +01:00

64 lines
2.0 KiB
C

/*
* Copyright (C) 2012,2013 - ARM Ltd
* Author: Marc Zyngier <marc.zyngier@arm.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __KVM_ARM_PSCI_H__
#define __KVM_ARM_PSCI_H__
#include <linux/kvm_host.h>
#include <uapi/linux/psci.h>
#define KVM_ARM_PSCI_0_1 PSCI_VERSION(0, 1)
#define KVM_ARM_PSCI_0_2 PSCI_VERSION(0, 2)
#define KVM_ARM_PSCI_1_0 PSCI_VERSION(1, 0)
#define KVM_ARM_PSCI_LATEST KVM_ARM_PSCI_1_0
/*
* We need the KVM pointer independently from the vcpu as we can call
* this from HYP, and need to apply kern_hyp_va on it...
*/
static inline int kvm_psci_version(struct kvm_vcpu *vcpu, struct kvm *kvm)
{
/*
* Our PSCI implementation stays the same across versions from
* v0.2 onward, only adding the few mandatory functions (such
* as FEATURES with 1.0) that are required by newer
* revisions. It is thus safe to return the latest, unless
* userspace has instructed us otherwise.
*/
if (test_bit(KVM_ARM_VCPU_PSCI_0_2, vcpu->arch.features)) {
if (vcpu->kvm->arch.psci_version)
return vcpu->kvm->arch.psci_version;
return KVM_ARM_PSCI_LATEST;
}
return KVM_ARM_PSCI_0_1;
}
int kvm_hvc_call_handler(struct kvm_vcpu *vcpu);
struct kvm_one_reg;
int kvm_arm_get_fw_num_regs(struct kvm_vcpu *vcpu);
int kvm_arm_copy_fw_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices);
int kvm_arm_get_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg);
int kvm_arm_set_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg);
#endif /* __KVM_ARM_PSCI_H__ */