[PATCH v2 08/12] KVM: arm64: nv: Add trap routing for CNTHCTL_EL2.EL1{NVPCT,NVVCT,TVT,TVCT}

Marc Zyngier
2024-12-17T14:23:28Z

For completeness, fun, and cerebral meltdown, add the virtualisation
related traps to the counter and timers.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/kvm/emulate-nested.c | 58 +++++++++++++++++++++++++++++++--
1 file changed, 56 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kvm/emulate-nested.c b/arch/arm64/kvm/emulate-nested.c
index 1ffbfd1c3cf2e..03d21044c41f5 100644
--- a/arch/arm64/kvm/emulate-nested.c
+++ b/arch/arm64/kvm/emulate-nested.c
@@ -89,6 +89,9 @@ enum cgt_group_id {
CGT_HCRX_EnFPM,
CGT_HCRX_TCR2En,

+ CGT_CNTHCTL_EL1TVT,
+ CGT_CNTHCTL_EL1TVCT,
+
CGT_ICH_HCR_TC,
CGT_ICH_HCR_TALL0,
CGT_ICH_HCR_TALL1,
@@ -124,6 +127,8 @@ enum cgt_group_id {
__COMPLEX_CONDITIONS__,
CGT_CNTHCTL_EL1PCTEN = __COMPLEX_CONDITIONS__,
CGT_CNTHCTL_EL1PTEN,
+ CGT_CNTHCTL_EL1NVPCT,
+ CGT_CNTHCTL_EL1NVVCT,

CGT_CPTR_TTA,
CGT_MDCR_HPMN,
@@ -393,6 +398,18 @@ static const struct trap_bits coarse_trap_bits[] = {
.mask = HCRX_EL2_TCR2En,
.behaviour = BEHAVE_FORWARD_RW,
},
+ [CGT_CNTHCTL_EL1TVT] = {
+ .index = CNTHCTL_EL2,
+ .value = CNTHCTL_EL1TVT,
+ .mask = CNTHCTL_EL1TVT,
+ .behaviour = BEHAVE_FORWARD_RW,
+ },
+ [CGT_CNTHCTL_EL1TVCT] = {
+ .index = CNTHCTL_EL2,
+ .value = CNTHCTL_EL1TVCT,
+ .mask = CNTHCTL_EL1TVCT,
+ .behaviour = BEHAVE_FORWARD_READ,
+ },
[CGT_ICH_HCR_TC] = {
.index = ICH_HCR_EL2,
.value = ICH_HCR_TC,
@@ -487,6 +504,32 @@ static enum trap_behaviour check_cnthctl_el1pten(struct kvm_vcpu *vcpu)
return BEHAVE_FORWARD_RW;
}

+static bool is_nested_nv2_guest(struct kvm_vcpu *vcpu)
+{
+ u64 val;
+
+ val = __vcpu_sys_reg(vcpu, HCR_EL2);
+ return ((val & (HCR_E2H | HCR_TGE | HCR_NV2 | HCR_NV1 | HCR_NV)) == (HCR_E2H | HCR_NV2 | HCR_NV));
+}
+
+static enum trap_behaviour check_cnthctl_el1nvpct(struct kvm_vcpu *vcpu)
+{
+ if (!is_nested_nv2_guest(vcpu) ||
+ !(__vcpu_sys_reg(vcpu, CNTHCTL_EL2) & CNTHCTL_EL1NVPCT))
+ return BEHAVE_HANDLE_LOCALLY;
+
+ return BEHAVE_FORWARD_RW;
+}
+
+static enum trap_behaviour check_cnthctl_el1nvvct(struct kvm_vcpu *vcpu)
+{
+ if (!is_nested_nv2_guest(vcpu) ||
+ !(__vcpu_sys_reg(vcpu, CNTHCTL_EL2) & CNTHCTL_EL1NVVCT))
+ return BEHAVE_HANDLE_LOCALLY;
+
+ return BEHAVE_FORWARD_RW;
+}
+
static enum trap_behaviour check_cptr_tta(struct kvm_vcpu *vcpu)
{
u64 val = __vcpu_sys_reg(vcpu, CPTR_EL2);
@@ -534,6 +577,8 @@ static enum trap_behaviour check_mdcr_hpmn(struct kvm_vcpu *vcpu)
static const complex_condition_check ccc[] = {
CCC(CGT_CNTHCTL_EL1PCTEN, check_cnthctl_el1pcten),
CCC(CGT_CNTHCTL_EL1PTEN, check_cnthctl_el1pten),
+ CCC(CGT_CNTHCTL_EL1NVPCT, check_cnthctl_el1nvpct),
+ CCC(CGT_CNTHCTL_EL1NVVCT, check_cnthctl_el1nvvct),
CCC(CGT_CPTR_TTA, check_cptr_tta),
CCC(CGT_MDCR_HPMN, check_mdcr_hpmn),
};
@@ -850,11 +895,15 @@ static const struct encoding_to_trap_config encoding_to_cgt[] __initconst = {
SYS_CNTHP_CVAL_EL2, CGT_HCR_NV),
SR_RANGE_TRAP(SYS_CNTHV_TVAL_EL2,
SYS_CNTHV_CVAL_EL2, CGT_HCR_NV),
- /* All _EL02, _EL12 registers */
+ /* All _EL02, _EL12 registers up to CNTKCTL_EL12*/
SR_RANGE_TRAP(sys_reg(3, 5, 0, 0, 0),
sys_reg(3, 5, 10, 15, 7), CGT_HCR_NV),
SR_RANGE_TRAP(sys_reg(3, 5, 12, 0, 0),
- sys_reg(3, 5, 14, 15, 7), CGT_HCR_NV),
+ sys_reg(3, 5, 14, 1, 0), CGT_HCR_NV),
+ SR_TRAP(SYS_CNTP_CTL_EL02, CGT_CNTHCTL_EL1NVPCT),
+ SR_TRAP(SYS_CNTP_CVAL_EL02, CGT_CNTHCTL_EL1NVPCT),
+ SR_TRAP(SYS_CNTV_CTL_EL02, CGT_CNTHCTL_EL1NVVCT),
+ SR_TRAP(SYS_CNTV_CVAL_EL02, CGT_CNTHCTL_EL1NVVCT),
SR_TRAP(OP_AT_S1E2R, CGT_HCR_NV),
SR_TRAP(OP_AT_S1E2W, CGT_HCR_NV),
SR_TRAP(OP_AT_S12E1R, CGT_HCR_NV),
@@ -1184,6 +1233,11 @@ static const struct encoding_to_trap_config encoding_to_cgt[] __initconst = {
SR_TRAP(SYS_CNTP_CTL_EL0, CGT_CNTHCTL_EL1PTEN),
SR_TRAP(SYS_CNTPCT_EL0, CGT_CNTHCTL_EL1PCTEN),
SR_TRAP(SYS_CNTPCTSS_EL0, CGT_CNTHCTL_EL1PCTEN),
+ SR_TRAP(SYS_CNTV_TVAL_EL0, CGT_CNTHCTL_EL1TVT),
+ SR_TRAP(SYS_CNTV_CVAL_EL0, CGT_CNTHCTL_EL1TVT),
+ SR_TRAP(SYS_CNTV_CTL_EL0, CGT_CNTHCTL_EL1TVT),
+ SR_TRAP(SYS_CNTVCT_EL0, CGT_CNTHCTL_EL1TVCT),
+ SR_TRAP(SYS_CNTVCTSS_EL0, CGT_CNTHCTL_EL1TVCT),
SR_TRAP(SYS_FPMR, CGT_HCRX_EnFPM),
/*
* IMPDEF choice:
--
2.39.2