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KVM: arm64: Handle counter access early in non-HYP context

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We already deal with CNTPCT_EL0 accesses in non-HYP context.
Let's add CNTVCT_EL0 as a good measure.

This is also an opportunity to simplify things and make it
plain that this code is only for non-HYP context handling.

Acked-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20241217142321.763801-8-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
This commit is contained in:
Marc Zyngier 2024-12-17 14:23:15 +00:00
parent 9b3b2f0029
commit b86fc215dc
1 changed files with 21 additions and 13 deletions
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34
arch/arm64/kvm/hyp/include/hyp/switch.h
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@ -506,7 +506,7 @@ static inline u64 compute_counter_value(struct arch_timer_context *ctxt)
return arch_timer_read_cntpct_el0() - timer_get_offset(ctxt); return arch_timer_read_cntpct_el0() - timer_get_offset(ctxt);
} }
static bool kvm_hyp_handle_cntpct(struct kvm_vcpu *vcpu) static bool kvm_handle_cntxct(struct kvm_vcpu *vcpu)
{ {
struct arch_timer_context *ctxt; struct arch_timer_context *ctxt;
u32 sysreg; u32 sysreg;
@ -516,18 +516,19 @@ static bool kvm_hyp_handle_cntpct(struct kvm_vcpu *vcpu)
* We only get here for 64bit guests, 32bit guests will hit * We only get here for 64bit guests, 32bit guests will hit
* the long and winding road all the way to the standard * the long and winding road all the way to the standard
* handling. Yes, it sucks to be irrelevant. * handling. Yes, it sucks to be irrelevant.
*
* Also, we only deal with non-hypervisor context here (either
* an EL1 guest, or a non-HYP context of an EL2 guest).
*/ */
if (is_hyp_ctxt(vcpu))
return false;
sysreg = esr_sys64_to_sysreg(kvm_vcpu_get_esr(vcpu)); sysreg = esr_sys64_to_sysreg(kvm_vcpu_get_esr(vcpu));
switch (sysreg) { switch (sysreg) {
case SYS_CNTPCT_EL0: case SYS_CNTPCT_EL0:
case SYS_CNTPCTSS_EL0: case SYS_CNTPCTSS_EL0:
if (vcpu_has_nv(vcpu)) { if (vcpu_has_nv(vcpu)) {
if (is_hyp_ctxt(vcpu)) {
ctxt = vcpu_hptimer(vcpu);
break;
}
/* Check for guest hypervisor trapping */ /* Check for guest hypervisor trapping */
val = __vcpu_sys_reg(vcpu, CNTHCTL_EL2); val = __vcpu_sys_reg(vcpu, CNTHCTL_EL2);
if (!vcpu_el2_e2h_is_set(vcpu)) if (!vcpu_el2_e2h_is_set(vcpu))
@ -539,16 +540,23 @@ static bool kvm_hyp_handle_cntpct(struct kvm_vcpu *vcpu)
ctxt = vcpu_ptimer(vcpu); ctxt = vcpu_ptimer(vcpu);
break; break;
case SYS_CNTVCT_EL0:
case SYS_CNTVCTSS_EL0:
if (vcpu_has_nv(vcpu)) {
/* Check for guest hypervisor trapping */
val = __vcpu_sys_reg(vcpu, CNTHCTL_EL2);
if (val & CNTHCTL_EL1TVCT)
return false;
}
ctxt = vcpu_vtimer(vcpu);
break;
default: default:
return false; return false;
} }
val = arch_timer_read_cntpct_el0(); val = compute_counter_value(ctxt);
if (ctxt->offset.vm_offset)
val -= *kern_hyp_va(ctxt->offset.vm_offset);
if (ctxt->offset.vcpu_offset)
val -= *kern_hyp_va(ctxt->offset.vcpu_offset);
vcpu_set_reg(vcpu, kvm_vcpu_sys_get_rt(vcpu), val); vcpu_set_reg(vcpu, kvm_vcpu_sys_get_rt(vcpu), val);
__kvm_skip_instr(vcpu); __kvm_skip_instr(vcpu);
@ -593,7 +601,7 @@ static bool kvm_hyp_handle_sysreg(struct kvm_vcpu *vcpu, u64 *exit_code)
__vgic_v3_perform_cpuif_access(vcpu) == 1) __vgic_v3_perform_cpuif_access(vcpu) == 1)
return true; return true;
if (kvm_hyp_handle_cntpct(vcpu)) if (kvm_handle_cntxct(vcpu))
return true; return true;
return false; return false;