Re: [PATCH v3] ACPI/processor_idle: Remove dummy wait if kernel is in guest mode

2019-10-23 Thread Rafael J. Wysocki
On Wed, Oct 23, 2019 at 10:45 AM David Laight wrote: > > From: Yin Fengwei > > Sent: 23 October 2019 08:50 > > > > In function acpi_idle_do_entry(), an ioport access is used for dummy > > wait to guarantee hardware behavior. But it could trigger unnecessary > > vmexit if kernel is running as guest

RE: [PATCH v3] ACPI/processor_idle: Remove dummy wait if kernel is in guest mode

2019-10-23 Thread David Laight
From: Yin Fengwei > Sent: 23 October 2019 08:50 > In function acpi_idle_do_entry(), an ioport access is used for dummy > wait to guarantee hardware behavior. But it could trigger unnecessary > vmexit if kernel is running as guest in virtualization environtment. > > If it's in virtualization envi

[PATCH v3] ACPI/processor_idle: Remove dummy wait if kernel is in guest mode

2019-10-23 Thread Yin Fengwei
In function acpi_idle_do_entry(), an ioport access is used for dummy wait to guarantee hardware behavior. But it could trigger unnecessary vmexit if kernel is running as guest in virtualization environtment. If it's in virtualization environment, the deeper C state enter operation (inb()) will tra