[PATCH v19 108/130] KVM: TDX: Handle TDX PV HLT hypercall

isaku.yamahata
2024-02-26T08:29:06Z

From: Isaku Yamahata <isaku.yamahata@intel.com>

Wire up TDX PV HLT hypercall to the KVM backend function.

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
---
v19:
- move tdvps_state_non_arch_check() to this patch

v18:
- drop buggy_hlt_workaround and use TDH.VP.RD(TD_VCPU_STATE_DETAILS)

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
---
arch/x86/kvm/vmx/tdx.c | 26 +++++++++++++++++++++++++-
arch/x86/kvm/vmx/tdx.h | 4 ++++
2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index eb68d6c148b6..a2caf2ae838c 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -688,7 +688,18 @@ void tdx_vcpu_load(struct kvm_vcpu *vcpu, int cpu)

bool tdx_protected_apic_has_interrupt(struct kvm_vcpu *vcpu)
{
- return pi_has_pending_interrupt(vcpu);
+ bool ret = pi_has_pending_interrupt(vcpu);
+ union tdx_vcpu_state_details details;
+ struct vcpu_tdx *tdx = to_tdx(vcpu);
+
+ if (ret || vcpu->arch.mp_state != KVM_MP_STATE_HALTED)
+ return true;
+
+ if (tdx->interrupt_disabled_hlt)
+ return false;
+
+ details.full = td_state_non_arch_read64(tdx, TD_VCPU_STATE_DETAILS_NON_ARCH);
+ return !!details.vmxip;
}

void tdx_prepare_switch_to_guest(struct kvm_vcpu *vcpu)
@@ -1130,6 +1141,17 @@ static int tdx_emulate_cpuid(struct kvm_vcpu *vcpu)
return 1;
}

+static int tdx_emulate_hlt(struct kvm_vcpu *vcpu)
+{
+ struct vcpu_tdx *tdx = to_tdx(vcpu);
+
+ /* See tdx_protected_apic_has_interrupt() to avoid heavy seamcall */
+ tdx->interrupt_disabled_hlt = tdvmcall_a0_read(vcpu);
+
+ tdvmcall_set_return_code(vcpu, TDVMCALL_SUCCESS);
+ return kvm_emulate_halt_noskip(vcpu);
+}
+
static int handle_tdvmcall(struct kvm_vcpu *vcpu)
{
if (tdvmcall_exit_type(vcpu))
@@ -1138,6 +1160,8 @@ static int handle_tdvmcall(struct kvm_vcpu *vcpu)
switch (tdvmcall_leaf(vcpu)) {
case EXIT_REASON_CPUID:
return tdx_emulate_cpuid(vcpu);
+ case EXIT_REASON_HLT:
+ return tdx_emulate_hlt(vcpu);
default:
break;
}
diff --git a/arch/x86/kvm/vmx/tdx.h b/arch/x86/kvm/vmx/tdx.h
index 4399d474764f..11c74c34555f 100644
--- a/arch/x86/kvm/vmx/tdx.h
+++ b/arch/x86/kvm/vmx/tdx.h
@@ -104,6 +104,8 @@ struct vcpu_tdx {
bool host_state_need_restore;
u64 msr_host_kernel_gs_base;

+ bool interrupt_disabled_hlt;
+
/*
* Dummy to make pmu_intel not corrupt memory.
* TODO: Support PMU for TDX. Future work.
@@ -166,6 +168,7 @@ static __always_inline void tdvps_vmcs_check(u32 field, u8 bits)
}

static __always_inline void tdvps_management_check(u64 field, u8 bits) {}
+static __always_inline void tdvps_state_non_arch_check(u64 field, u8 bits) {}

#define TDX_BUILD_TDVPS_ACCESSORS(bits, uclass, lclass) \
static __always_inline u##bits td_##lclass##_read##bits(struct vcpu_tdx *tdx, \
@@ -226,6 +229,7 @@ TDX_BUILD_TDVPS_ACCESSORS(32, VMCS, vmcs);
TDX_BUILD_TDVPS_ACCESSORS(64, VMCS, vmcs);

TDX_BUILD_TDVPS_ACCESSORS(8, MANAGEMENT, management);
+TDX_BUILD_TDVPS_ACCESSORS(64, STATE_NON_ARCH, state_non_arch);

static __always_inline u64 td_tdcs_exec_read64(struct kvm_tdx *kvm_tdx, u32 field)
{
--
2.25.1