Re: [PATCHv10 04/18] cpu/hotplug, x86/acpi: Disable CPU offlining for ACPI MADT wakeup

2024-04-24 Thread Borislav Petkov
On Wed, Apr 24, 2024 at 07:40:26AM -0700, Dave Hansen wrote: > On 4/24/24 07:35, Kirill A. Shutemov wrote: > >> Also, does this need to go to stable although it is kinda big for > >> stable. If stable, do we need a smaller fix first which is backportable? > > Correct me, if I am wrong, but I

Re: [PATCHv10 04/18] cpu/hotplug, x86/acpi: Disable CPU offlining for ACPI MADT wakeup

2024-04-24 Thread Dave Hansen
On 4/24/24 07:35, Kirill A. Shutemov wrote: >> Also, does this need to go to stable although it is kinda big for >> stable. If stable, do we need a smaller fix first which is backportable? > Correct me, if I am wrong, but I believe TDX guest is the only user of > ACPI MADT wake up method. At least

Re: [PATCHv10 04/18] cpu/hotplug, x86/acpi: Disable CPU offlining for ACPI MADT wakeup

2024-04-24 Thread Kirill A. Shutemov
On Wed, Apr 24, 2024 at 03:50:52PM +0200, Borislav Petkov wrote: > On Wed, Apr 24, 2024 at 11:38:42AM +0300, Kirill A. Shutemov wrote: > > It was wrong from beginning. If ACPI MADT wake up method is used on the > > platform, we cannot handle offline, regardless if it is TDX or not. > > Sounds to

Re: [PATCHv10 04/18] cpu/hotplug, x86/acpi: Disable CPU offlining for ACPI MADT wakeup

2024-04-24 Thread Borislav Petkov
On Wed, Apr 24, 2024 at 11:38:42AM +0300, Kirill A. Shutemov wrote: > It was wrong from beginning. If ACPI MADT wake up method is used on the > platform, we cannot handle offline, regardless if it is TDX or not. Sounds to me like this fact should be a prominent part of the commit message and

Re: [PATCHv10 04/18] cpu/hotplug, x86/acpi: Disable CPU offlining for ACPI MADT wakeup

2024-04-24 Thread Kirill A. Shutemov
On Tue, Apr 23, 2024 at 06:02:58PM +0200, Borislav Petkov wrote: > > > > Currently CPU hotplug is prevented based on the confidential computing > > attribute which is set for Intel TDX. But TDX is not the only possible > > user of the wake up method. > > > > Disable CPU offlining on ACPI MADT

Re: [PATCHv10 04/18] cpu/hotplug, x86/acpi: Disable CPU offlining for ACPI MADT wakeup

2024-04-23 Thread Borislav Petkov
On Tue, Apr 09, 2024 at 02:29:56PM +0300, Kirill A. Shutemov wrote: > ACPI MADT doesn't allow to offline CPU after it got woke up. In all your text: s/woke/woken/g > > Currently CPU hotplug is prevented based on the confidential computing > attribute which is set for Intel TDX. But TDX is not