On Thu, May 12, 2022 at 11:17:41AM +0800,
Xiaoyao Li <xiaoyao.li@xxxxxxxxx> wrote:
> 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).
Just to make it sure.
You didn't use VM-scoped KVM_SET_TSC_KHZ because KVM side patch is still in
kvm/queue? Once the patch lands, we should use it.
Thanks,
>
> 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
>
>
--
Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
