Reuse "-cpu,tsc-frequency=" to get user wanted tsc frequency and pass it
to KVM_TDX_INIT_VM.
Besides, sanity check the tsc frequency to be in the legal range and
legal granularity (required by TDX module).
Signed-off-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
---
target/i386/kvm/kvm.c | 8 ++++++++
target/i386/kvm/tdx.c | 18 ++++++++++++++++++
2 files changed, 26 insertions(+)
diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index f2d7c3cf59ac..c51125ab200f 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -818,6 +818,14 @@ static int kvm_arch_set_tsc_khz(CPUState *cs)
int r, cur_freq;
bool set_ioctl = false;
+ /*
+ * TD guest's TSC is immutable, it cannot be set/changed via
+ * KVM_SET_TSC_KHZ, but only be initialized via KVM_TDX_INIT_VM
+ */
+ if (is_tdx_vm()) {
+ return 0;
+ }
+
if (!env->tsc_khz) {
return 0;
}
diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c
index 9f2cdf640b5c..622efc409438 100644
--- a/target/i386/kvm/tdx.c
+++ b/target/i386/kvm/tdx.c
@@ -35,6 +35,9 @@
#define TDX_TD_ATTRIBUTES_PKS BIT_ULL(30)
#define TDX_TD_ATTRIBUTES_PERFMON BIT_ULL(63)
+#define TDX_MIN_TSC_FREQUENCY_KHZ (100 * 1000)
+#define TDX_MAX_TSC_FREQUENCY_KHZ (10 * 1000 * 1000)
+
static TdxGuest *tdx_guest;
/* It's valid after kvm_confidential_guest_init()->kvm_tdx_init() */
@@ -211,6 +214,20 @@ int tdx_pre_create_vcpu(CPUState *cpu)
goto out;
}
+ r = -EINVAL;
+ if (env->tsc_khz && (env->tsc_khz < TDX_MIN_TSC_FREQUENCY_KHZ ||
+ env->tsc_khz > TDX_MAX_TSC_FREQUENCY_KHZ)) {
+ error_report("Invalid TSC %ld KHz, must specify cpu_frequency between [%d, %d] kHz",
+ env->tsc_khz, TDX_MIN_TSC_FREQUENCY_KHZ,
+ TDX_MAX_TSC_FREQUENCY_KHZ);
+ goto out;
+ }
+
+ if (env->tsc_khz % (25 * 1000)) {
+ error_report("Invalid TSC %ld KHz, it must be multiple of 25MHz", env->tsc_khz);
+ goto out;
+ }
+
r = setup_td_guest_attributes(x86cpu);
if (r) {
goto out;
@@ -221,6 +238,7 @@ int tdx_pre_create_vcpu(CPUState *cpu)
init_vm.attributes = tdx_guest->attributes;
init_vm.max_vcpus = ms->smp.cpus;
+ init_vm.tsc_khz = env->tsc_khz;
r = tdx_vm_ioctl(KVM_TDX_INIT_VM, 0, &init_vm);
if (r < 0) {
--
2.27.0
