Commit ec6449a9 authored by Christoffer Dall's avatar Christoffer Dall
Browse files

KVM: arm/arm64: Don't enable/disable physical timer access on VHE 



After the timer optimization rework we accidentally end up calling
physical timer enable/disable functions on VHE systems, which is neither
needed nor correct, since the CNTHCTL_EL2 register format is
different when HCR_EL2.E2H is set.

The CNTHCTL_EL2 is initialized when CPUs become online in
kvm_timer_init_vhe() and we don't have to call these functions on VHE
systems, which also allows us to inline the non-VHE functionality.

Reported-by: default avatarJintack Lim <jintack@cs.columbia.edu>
Signed-off-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
parent 4fbd8d19

include/kvm/arm_arch_timer.h

+0 −3
Original line number Diff line number Diff line
@@ -93,7 +93,4 @@ void kvm_timer_init_vhe(void); 
#define vcpu_vtimer(v)	(&(v)->arch.timer_cpu.vtimer)

#define vcpu_ptimer(v)	(&(v)->arch.timer_cpu.ptimer)



void enable_el1_phys_timer_access(void);

void disable_el1_phys_timer_access(void);



#endif

virt/kvm/arm/arch_timer.c

+0 −6
Original line number Diff line number Diff line
@@ -479,9 +479,6 @@ void kvm_timer_vcpu_load(struct kvm_vcpu *vcpu) 


	vtimer_restore_state(vcpu);



	if (has_vhe())

		disable_el1_phys_timer_access();



	/* Set the background timer for the physical timer emulation. */

	phys_timer_emulate(vcpu);

}
@@ -510,9 +507,6 @@ void kvm_timer_vcpu_put(struct kvm_vcpu *vcpu) 
	if (unlikely(!timer->enabled))

		return;



	if (has_vhe())

		enable_el1_phys_timer_access();



	vtimer_save_state(vcpu);



	/*

virt/kvm/arm/hyp/timer-sr.c

+20 −28
Original line number Diff line number Diff line
@@ -27,8 +27,13 @@ void __hyp_text __kvm_timer_set_cntvoff(u32 cntvoff_low, u32 cntvoff_high) 
	write_sysreg(cntvoff, cntvoff_el2);

}



void __hyp_text enable_el1_phys_timer_access(void)

void __hyp_text __timer_disable_traps(struct kvm_vcpu *vcpu)

{

	/*

	 * We don't need to do this for VHE since the host kernel runs in EL2

	 * with HCR_EL2.TGE ==1, which makes those bits have no impact.

	 */

	if (!has_vhe()) {

		u64 val;



		/* Allow physical timer/counter access for the host */
@@ -36,9 +41,11 @@ void __hyp_text enable_el1_phys_timer_access(void) 
		val |= CNTHCTL_EL1PCTEN | CNTHCTL_EL1PCEN;

		write_sysreg(val, cnthctl_el2);

	}

}



void __hyp_text disable_el1_phys_timer_access(void)

void __hyp_text __timer_enable_traps(struct kvm_vcpu *vcpu)

{

	if (!has_vhe()) {

		u64 val;



		/*
@@ -50,19 +57,4 @@ void __hyp_text disable_el1_phys_timer_access(void) 
		val |= CNTHCTL_EL1PCTEN;

		write_sysreg(val, cnthctl_el2);

	}



void __hyp_text __timer_disable_traps(struct kvm_vcpu *vcpu)

{

	/*

	 * We don't need to do this for VHE since the host kernel runs in EL2

	 * with HCR_EL2.TGE ==1, which makes those bits have no impact.

	 */

	if (!has_vhe())

		enable_el1_phys_timer_access();

}



void __hyp_text __timer_enable_traps(struct kvm_vcpu *vcpu)

{

	if (!has_vhe())

		disable_el1_phys_timer_access();

}

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