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

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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: Jintack Lim <jintack@cs.columbia.edu>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
This commit is contained in:
Christoffer Dall
2017-11-20 12:10:15 +01:00
parent 4fbd8d194f
commit ec6449a9c2
3 changed files with 20 additions and 37 deletions
Download Patch File Download Diff File Expand all files Collapse all files

48
virt/kvm/arm/hyp/timer-sr.c
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@@ -27,42 +27,34 @@ 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)
{
u64 val;
/* Allow physical timer/counter access for the host */
val = read_sysreg(cnthctl_el2);
val |= CNTHCTL_EL1PCTEN | CNTHCTL_EL1PCEN;
write_sysreg(val, cnthctl_el2);
}
void __hyp_text disable_el1_phys_timer_access(void)
{
u64 val;
/*
* Disallow physical timer access for the guest
* Physical counter access is allowed
*/
val = read_sysreg(cnthctl_el2);
val &= ~CNTHCTL_EL1PCEN;
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();
if (!has_vhe()) {
u64 val;
/* Allow physical timer/counter access for the host */
val = read_sysreg(cnthctl_el2);
val |= CNTHCTL_EL1PCTEN | CNTHCTL_EL1PCEN;
write_sysreg(val, cnthctl_el2);
}
}
void __hyp_text __timer_enable_traps(struct kvm_vcpu *vcpu)
{
if (!has_vhe())
disable_el1_phys_timer_access();
if (!has_vhe()) {
u64 val;
/*
* Disallow physical timer access for the guest
* Physical counter access is allowed
*/
val = read_sysreg(cnthctl_el2);
val &= ~CNTHCTL_EL1PCEN;
val |= CNTHCTL_EL1PCTEN;
write_sysreg(val, cnthctl_el2);
}
}