Re: [PATCH v8 14/55] i386/tdx: Set APIC bus rate to match with what TDX module enforces

[Zhao Liu <zhao1.liu@intel.com>]

On Tue, Apr 01, 2025 at 09:01:24AM -0400, Xiaoyao Li wrote:
> Date: Tue,  1 Apr 2025 09:01:24 -0400
> From: Xiaoyao Li <xiaoyao.li@intel.com>
> Subject: [PATCH v8 14/55] i386/tdx: Set APIC bus rate to match with what
>  TDX module enforces
> X-Mailer: git-send-email 2.34.1
> 
> TDX advertises core crystal clock with cpuid[0x15] as 25MHz for TD
> guests and it's unchangeable from VMM. As a result, TDX guest reads
> the APIC timer as the same frequency, 25MHz.
> 
> While KVM's default emulated frequency for APIC bus is 1GHz, set the
> APIC bus rate to match with TDX explicitly to ensure KVM provide correct
> emulated APIC timer for TD guest.
> 
> Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
> ---
> Changes in v6:
>  - new patch;
> ---
>  target/i386/kvm/tdx.c | 13 +++++++++++++
>  target/i386/kvm/tdx.h |  3 +++
>  2 files changed, 16 insertions(+)

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>