Re: [RFC 0/3] x86: fix cpu hotplug with secure boot

[Laszlo Ersek]

On 07/14/20 11:58, Laszlo Ersek wrote:
> On 07/10/20 18:17, Igor Mammedov wrote:
>> CPU hotplug with Secure Boot was not really supported and firmware wasn't 
>> aware
>> of hotplugged CPUs (which might lead to guest crashes). During 4.2 we 
>> introduced
>> locked SMI handler RAM arrea to make sure that guest OS wasn't able to inject
>> its own SMI handler and OVMF added initial CPU hotplug support.
>>
>> This series is QEMU part of that support [1] which lets QMVF tell QEMU that
>> CPU hotplug with SMI broadcast enabled is supported so that QEMU would be 
>> able
>> to prevent hotplug in case it's not supported and trigger SMI on hotplug when
>> it's necessary. 
>>
>> 1) CPU hotplug negotiation part was introduced later so it might not be
>> in upstream OVMF yet or I might have missed the patch on edk2-devel
>> (Laszlo will point out to it/post formal patch)
> 
> I'll post it later, after testing it with this patch series.

(For the time being I had only attached it to
<https://bugzilla.redhat.com/show_bug.cgi?id=1849177#c1>.)

> 
> Thanks!
> Laszlo
> 
>>
>> Igor Mammedov (3):
>>   x86: lpc9: let firmware negotiate CPU hotplug SMI feature
>>   x86: cphp: prevent guest crash on CPU hotplug when broadcast SMI is in
>>     use
>>   x68: acpi: trigger SMI before scanning for hotplugged CPUs
>>
>>  include/hw/acpi/cpu.h  |  1 +
>>  include/hw/i386/ich9.h |  1 +
>>  hw/acpi/cpu.c          |  6 ++++++
>>  hw/acpi/ich9.c         | 12 +++++++++++-
>>  hw/i386/acpi-build.c   | 33 ++++++++++++++++++++++++++++++++-
>>  hw/i386/pc.c           | 15 ++++++++++++++-
>>  hw/isa/lpc_ich9.c      | 10 ++++++++++
>>  7 files changed, 75 insertions(+), 3 deletions(-)
>>
>