diff options
| -rw-r--r-- | arch/arm64/kvm/arch_timer.c | 36 | ||||
| -rw-r--r-- | include/clocksource/arm_arch_timer.h | 2 |
2 files changed, 35 insertions, 3 deletions
diff --git a/arch/arm64/kvm/arch_timer.c b/arch/arm64/kvm/arch_timer.c index 8bff913ed126..b6a06bda9e53 100644 --- a/arch/arm64/kvm/arch_timer.c +++ b/arch/arm64/kvm/arch_timer.c @@ -783,7 +783,7 @@ static void kvm_timer_vcpu_load_nested_switch(struct kvm_vcpu *vcpu, static void timer_set_traps(struct kvm_vcpu *vcpu, struct timer_map *map) { - bool tpt, tpc; + bool tvt, tpt, tvc, tpc, tvt02, tpt02; u64 clr, set; /* @@ -798,7 +798,29 @@ static void timer_set_traps(struct kvm_vcpu *vcpu, struct timer_map *map) * within this function, reality kicks in and we start adding * traps based on emulation requirements. */ - tpt = tpc = false; + tvt = tpt = tvc = tpc = false; + tvt02 = tpt02 = false; + + /* + * NV2 badly breaks the timer semantics by redirecting accesses to + * the EL1 timer state to memory, so let's call ECV to the rescue if + * available: we trap all CNT{P,V}_{CTL,CVAL,TVAL}_EL0 accesses. + * + * The treatment slightly varies depending whether we run a nVHE or + * VHE guest: nVHE will use the _EL0 registers directly, while VHE + * will use the _EL02 accessors. This translates in different trap + * bits. + * + * None of the trapping is required when running in non-HYP context, + * unless required by the L1 hypervisor settings once we advertise + * ECV+NV in the guest, or that we need trapping for other reasons. + */ + if (cpus_have_final_cap(ARM64_HAS_ECV) && is_hyp_ctxt(vcpu)) { + if (vcpu_el2_e2h_is_set(vcpu)) + tvt02 = tpt02 = true; + else + tvt = tpt = true; + } /* * We have two possibility to deal with a physical offset: @@ -838,6 +860,10 @@ static void timer_set_traps(struct kvm_vcpu *vcpu, struct timer_map *map) assign_clear_set_bit(tpt, CNTHCTL_EL1PCEN << 10, set, clr); assign_clear_set_bit(tpc, CNTHCTL_EL1PCTEN << 10, set, clr); + assign_clear_set_bit(tvt, CNTHCTL_EL1TVT, clr, set); + assign_clear_set_bit(tvc, CNTHCTL_EL1TVCT, clr, set); + assign_clear_set_bit(tvt02, CNTHCTL_EL1NVVCT, clr, set); + assign_clear_set_bit(tpt02, CNTHCTL_EL1NVPCT, clr, set); /* This only happens on VHE, so use the CNTHCTL_EL2 accessor. */ sysreg_clear_set(cnthctl_el2, clr, set); @@ -933,8 +959,12 @@ void kvm_timer_sync_nested(struct kvm_vcpu *vcpu) * accesses redirected to the VNCR page. Any guest action taken on * the timer is postponed until the next exit, leading to a very * poor quality of emulation. + * + * This is an unmitigated disaster, only papered over by FEAT_ECV, + * which allows trapping of the timer registers even with NV2. + * Still, this is still worse than FEAT_NV on its own. Meh. */ - if (!is_hyp_ctxt(vcpu)) + if (cpus_have_final_cap(ARM64_HAS_ECV) || !is_hyp_ctxt(vcpu)) return; if (!vcpu_el2_e2h_is_set(vcpu)) { diff --git a/include/clocksource/arm_arch_timer.h b/include/clocksource/arm_arch_timer.h index 877dcbb2601a..c62811fb4130 100644 --- a/include/clocksource/arm_arch_timer.h +++ b/include/clocksource/arm_arch_timer.h @@ -24,6 +24,8 @@ #define CNTHCTL_ECV (1 << 12) #define CNTHCTL_EL1TVT (1 << 13) #define CNTHCTL_EL1TVCT (1 << 14) +#define CNTHCTL_EL1NVPCT (1 << 15) +#define CNTHCTL_EL1NVVCT (1 << 16) enum arch_timer_reg { ARCH_TIMER_REG_CTRL, |