Re: [PATCH RFC 0/5] Change ghes driver to use HEST-based offsets

[Mauro Carvalho Chehab <mchehab+huawei@kernel.org>]

Em Wed, 2 Oct 2024 15:45:34 +0200
Igor Mammedov <imammedo@redhat.com> escreveu:

> On Tue,  1 Oct 2024 13:42:45 +0200
> Mauro Carvalho Chehab <mchehab+huawei@kernel.org> wrote:
> 
> > This RFC series was part of the previous PR to add generic error injection
> > support on GHES.
> > 
> > It contains only the changes of the math used to calculate offsets at
> > HEST table and hardware_error firmware file.
> > 
> > The first patch adds a new firmware file to store HEST address.
> > The second patch makes use of it.
> > The remaining ones add migration support.
> > 
> > PS.: I'm sending this as a RFC as using the proceudure defined at the
> > pseudo-migration of:
> > 
> > 	https://www.linux-kvm.org/page/Migration
> > 
> > Didn't work. I tried to use two different QEMU versions to check a
> > real life case and also to use just one QEMU and trying to load a
> > virt-9.1 state on a virt-9.2 machine. 
> > 
> > For instance, trying to restore a virt-9.1 state on virt-9.2 gave me
> > this error:
> > 
> > 	(qemu) qemu: Machine type received is 'virt-9.1' and local is 'virt-9.2'
> > 	qemu: load of migration failed: Invalid argument  
> 
> that's expected (idea is to keep machine type (virt-X) ABI stable so
> it would work the same way on old and new QEMU)
> migration is meant to move VM of the same machine type to a new/another QEMU instance.

I found a couple of issues and, after the fixes, it can successfully
migrate both virt-9.1 and virt-9.2 machines. 

> 
> i.e try migrate 
> 
> qemu-9.1 -M virt-9.1  => qemu-9.2 -M virt-9.1
> and vice-versa
> migration should succeed and memory error injection should still work
> the old way in both instances (I don't recall anymore how to simulate SEA,
> perhaps original author left a description how to do that somewhere on mail-list).

Those work as well, but I had to pass -cpu cortex-a57 to both 9.1
and 9.2, as using -cpu max caused qemu to refuse loading the guest.

I tested with both:

	qemu-9.1 -M virt-9.1 -cpu cortex-a57 => qemu-9.2 -M virt-9.1 -cpu cortex-a57
	qemu-9.2 -M virt-9.1 -cpu cortex-a57 => qemu-9.1 -M virt-9.1 -cpu cortex-a57

I'll address your other comments to the series and post a new version
today.

Thanks,
Mauro