On 5/03/2024 9:21 pm, Isaku Yamahata wrote:
On Fri, Mar 01, 2024 at 03:25:31PM +0800,
Yan Zhao <yan.y.zhao@xxxxxxxxx> wrote:
+ * TD_PARAMS is provided as an input to TDH_MNG_INIT, the size of which is 1024B.
+ */
+#define TDX_MAX_VCPUS (~(u16)0)
This value will be treated as -1 in tdx_vm_init(),
"kvm->max_vcpus = min(kvm->max_vcpus, TDX_MAX_VCPUS);"
This will lead to kvm->max_vcpus being -1 by default.
Is this by design or just an error?
If it's by design, why not set kvm->max_vcpus = -1 in tdx_vm_init() directly.
If an unexpected error, may below is better?
#define TDX_MAX_VCPUS (int)((u16)(~0UL))
or
#define TDX_MAX_VCPUS 65536
You're right. I'll use ((int)U16_MAX).
As TDX 1.5 introduced metadata MAX_VCPUS_PER_TD, I'll update to get the value
and trim it further. Something following.
[...]
+ u16 max_vcpus_per_td;
+
[...]
- kvm->max_vcpus = min(kvm->max_vcpus, TDX_MAX_VCPUS);
+ kvm->max_vcpus = min3(kvm->max_vcpus, tdx_info->max_vcpus_per_td,
+ TDX_MAX_VCPUS);
[...]
-#define TDX_MAX_VCPUS (~(u16)0)
+#define TDX_MAX_VCPUS ((int)U16_MAX)
Why do you even need TDX_MAX_VCPUS, given it cannot exceed U16_MAX and
you will have the 'u16 max_vcpus_per_td' anyway?
IIUC, in KVM_ENABLE_CAP(KVM_CAP_MAX_VCPUS), we can overwrite the
kvm->max_vcpus to the 'max_vcpus' provided by the userspace, and make
sure it doesn't exceed tdx_info->max_vcpus_per_td.
Anything I am missing?
