+ KVM maillist.
On 6/5/2023 11:47 PM, arjan@xxxxxxxxxxxxxxx wrote:
...
+static int __init intel_idle_vminit(const struct x86_cpu_id *id)
+{
+ int retval;
+
+ cpuidle_state_table = vmguest_cstates;
+
+ icpu = (const struct idle_cpu *)id->driver_data;
+
+ pr_debug("v" INTEL_IDLE_VERSION " model 0x%X\n",
+ boot_cpu_data.x86_model);
+
+ intel_idle_cpuidle_devices = alloc_percpu(struct cpuidle_device);
+ if (!intel_idle_cpuidle_devices)
+ return -ENOMEM;
+
+ intel_idle_cpuidle_driver_init(&intel_idle_driver);
+
+ retval = cpuidle_register_driver(&intel_idle_driver);
+ if (retval) {
+ struct cpuidle_driver *drv = cpuidle_get_driver();
+ printk(KERN_DEBUG pr_fmt("intel_idle yielding to %s\n"),
+ drv ? drv->name : "none");
+ goto init_driver_fail;
+ }
+
+ retval = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "idle/intel:online",
+ intel_idle_cpu_online, NULL);
+ if (retval < 0)
+ goto hp_setup_fail;
+
+ return 0;
+hp_setup_fail:
+ intel_idle_cpuidle_devices_uninit();
+ cpuidle_unregister_driver(&intel_idle_driver);
+init_driver_fail:
+ free_percpu(intel_idle_cpuidle_devices);
+ return retval;
+}
+
static int __init intel_idle_init(void)
{
const struct x86_cpu_id *id;
@@ -2074,6 +2195,8 @@ static int __init intel_idle_init(void)
id = x86_match_cpu(intel_idle_ids);
if (id) {
if (!boot_cpu_has(X86_FEATURE_MWAIT)) {
+ if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
+ return intel_idle_vminit(id);
It leads to below MSR access error on SPR.
[ 4.158636] unchecked MSR access error: RDMSR from 0xe2 at rIP:
0xffffffffbcaeebed (intel_idle_init_cstates_icpu.constprop.0+0x2dd/0x5a0)
[ 4.174991] Call Trace:
[ 4.179611] <TASK>
[ 4.183610] ? ex_handler_msr+0x11e/0x150
[ 4.190624] ? fixup_exception+0x17e/0x3c0
[ 4.197648] ? gp_try_fixup_and_notify+0x1d/0xc0
[ 4.205579] ? exc_general_protection+0x1bb/0x410
[ 4.213620] ? asm_exc_general_protection+0x26/0x30
[ 4.221624] ? __pfx_intel_idle_init+0x10/0x10
[ 4.228588] ? intel_idle_init_cstates_icpu.constprop.0+0x2dd/0x5a0
[ 4.238632] ? __pfx_intel_idle_init+0x10/0x10
[ 4.246632] ? __pfx_intel_idle_init+0x10/0x10
[ 4.253616] intel_idle_vminit.isra.0+0xf5/0x1d0
[ 4.261580] ? __pfx_intel_idle_init+0x10/0x10
[ 4.269670] ? __pfx_intel_idle_init+0x10/0x10
[ 4.274605] do_one_initcall+0x50/0x230
[ 4.279873] do_initcalls+0xb3/0x130
[ 4.286535] kernel_init_freeable+0x255/0x310
[ 4.293688] ? __pfx_kernel_init+0x10/0x10
[ 4.300630] kernel_init+0x1a/0x1c0
[ 4.305681] ret_from_fork+0x29/0x50
[ 4.312700] </TASK>
On Intel SPR, the call site is
intel_idle_vminit()
-> intel_idle_cpuidle_driver_init()
-> intel_idle_init_cstates_icpu()
-> spr_idle_state_table_update()
-> rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr);
However, current KVM doesn't provide emulation for
MSR_PKG_CST_CONFIG_CONTROL. It leads to #GP on accessing.
pr_debug("Please enable MWAIT in BIOS SETUP\n");
return -ENODEV;
}
