Commit 680232a9 authored by Marc Zyngier's avatar Marc Zyngier
Browse files

KVM: arm64: timers: Allow save/restoring of the physical timer 



Nothing like being 10 year late to a party!

Now that userspace can set counter offsets, we can save/restore
the physical timer as well!

Nobody really cared so far, but you're welcome anyway.

Reviewed-by: default avatarColton Lewis <coltonlewis@google.com>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230330174800.2677007-9-maz@kernel.org
parent 30ec7997

arch/arm64/kvm/guest.c

+17 −12
Original line number Diff line number Diff line
@@ -590,11 +590,16 @@ static unsigned long num_core_regs(const struct kvm_vcpu *vcpu) 
	return copy_core_reg_indices(vcpu, NULL);

}



/**

 * ARM64 versions of the TIMER registers, always available on arm64

 */

static const u64 timer_reg_list[] = {

	KVM_REG_ARM_TIMER_CTL,

	KVM_REG_ARM_TIMER_CNT,

	KVM_REG_ARM_TIMER_CVAL,

	KVM_REG_ARM_PTIMER_CTL,

	KVM_REG_ARM_PTIMER_CNT,

	KVM_REG_ARM_PTIMER_CVAL,

};



#define NUM_TIMER_REGS 3

#define NUM_TIMER_REGS ARRAY_SIZE(timer_reg_list)



static bool is_timer_reg(u64 index)

{
@@ -602,6 +607,9 @@ static bool is_timer_reg(u64 index) 
	case KVM_REG_ARM_TIMER_CTL:

	case KVM_REG_ARM_TIMER_CNT:

	case KVM_REG_ARM_TIMER_CVAL:

	case KVM_REG_ARM_PTIMER_CTL:

	case KVM_REG_ARM_PTIMER_CNT:

	case KVM_REG_ARM_PTIMER_CVAL:

		return true;

	}

	return false;
@@ -609,14 +617,11 @@ static bool is_timer_reg(u64 index) 


static int copy_timer_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)

{

	if (put_user(KVM_REG_ARM_TIMER_CTL, uindices))

	for (int i = 0; i < NUM_TIMER_REGS; i++) {

		if (put_user(timer_reg_list[i], uindices))

			return -EFAULT;

		uindices++;

	if (put_user(KVM_REG_ARM_TIMER_CNT, uindices))

		return -EFAULT;

	uindices++;

	if (put_user(KVM_REG_ARM_TIMER_CVAL, uindices))

		return -EFAULT;

	}



	return 0;

}