Commit 795a0bba authored by Marc Zyngier's avatar Marc Zyngier
Browse files

KVM: arm64: Add helper for last ditch idreg adjustments 



We already have to perform a set of last-chance adjustments for
NV purposes. We will soon have to do the same for the GIC, so
introduce a helper for that exact purpose.

Reviewed-by: default avatarOliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20240827152517.3909653-5-maz@kernel.org


Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
parent 8d917e0a

arch/arm64/kvm/arm.c

+7 −7
Original line number Diff line number Diff line
@@ -46,6 +46,8 @@ 
#include <kvm/arm_pmu.h>

#include <kvm/arm_psci.h>



#include "sys_regs.h"



static enum kvm_mode kvm_mode = KVM_MODE_DEFAULT;



enum kvm_wfx_trap_policy {
@@ -821,15 +823,13 @@ int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu) 
			return ret;

	}



	if (vcpu_has_nv(vcpu)) {

		ret = kvm_init_nv_sysregs(vcpu->kvm);

	ret = kvm_finalize_sys_regs(vcpu);

	if (ret)

		return ret;

	}



	/*

	 * This needs to happen after NV has imposed its own restrictions on

	 * the feature set

	 * This needs to happen after any restriction has been applied

	 * to the feature set.

	 */

	kvm_calculate_traps(vcpu);

arch/arm64/kvm/nested.c

+5 −10
Original line number Diff line number Diff line
@@ -954,19 +954,16 @@ static void set_sysreg_masks(struct kvm *kvm, int sr, u64 res0, u64 res1) 
int kvm_init_nv_sysregs(struct kvm *kvm)

{

	u64 res0, res1;

	int ret = 0;



	mutex_lock(&kvm->arch.config_lock);

	lockdep_assert_held(&kvm->arch.config_lock);



	if (kvm->arch.sysreg_masks)

		goto out;

		return 0;



	kvm->arch.sysreg_masks = kzalloc(sizeof(*(kvm->arch.sysreg_masks)),

					 GFP_KERNEL_ACCOUNT);

	if (!kvm->arch.sysreg_masks) {

		ret = -ENOMEM;

		goto out;

	}

	if (!kvm->arch.sysreg_masks)

		return -ENOMEM;



	limit_nv_id_regs(kvm);
@@ -1195,8 +1192,6 @@ int kvm_init_nv_sysregs(struct kvm *kvm) 
	if (!kvm_has_feat(kvm, ID_AA64PFR0_EL1, AMU, V1P1))

		res0 |= ~(res0 | res1);

	set_sysreg_masks(kvm, HAFGRTR_EL2, res0, res1);

out:

	mutex_unlock(&kvm->arch.config_lock);



	return ret;

	return 0;

}

arch/arm64/kvm/sys_regs.c

+23 −0
Original line number Diff line number Diff line
@@ -4620,6 +4620,29 @@ void kvm_calculate_traps(struct kvm_vcpu *vcpu) 
	mutex_unlock(&kvm->arch.config_lock);

}



/*

 * Perform last adjustments to the ID registers that are implied by the

 * configuration outside of the ID regs themselves, as well as any

 * initialisation that directly depend on these ID registers (such as

 * RES0/RES1 behaviours). This is not the place to configure traps though.

 *

 * Because this can be called once per CPU, changes must be idempotent.

 */

int kvm_finalize_sys_regs(struct kvm_vcpu *vcpu)

{

	struct kvm *kvm = vcpu->kvm;



	guard(mutex)(&kvm->arch.config_lock);



	if (vcpu_has_nv(vcpu)) {

		int ret = kvm_init_nv_sysregs(kvm);

		if (ret)

			return ret;

	}



	return 0;

}



int __init kvm_sys_reg_table_init(void)

{

	bool valid = true;

arch/arm64/kvm/sys_regs.h

+2 −0
Original line number Diff line number Diff line
@@ -235,6 +235,8 @@ int kvm_sys_reg_set_user(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg, 


bool triage_sysreg_trap(struct kvm_vcpu *vcpu, int *sr_index);



int kvm_finalize_sys_regs(struct kvm_vcpu *vcpu);



#define AA32(_x)	.aarch32_map = AA32_##_x

#define Op0(_x) 	.Op0 = _x

#define Op1(_x) 	.Op1 = _x