Re: [PATCH Part2 v5 00/45] Add AMD Secure Nested Paging (SEV-SNP) Hypervisor Support

Joerg Roedel
2021-11-15T14:43:04Z

On Mon, Nov 15, 2021 at 12:30:59PM +0000, Dr. David Alan Gilbert wrote:
> Still; I wonder if it's best to kill the guest - maybe it's best for
> the host to kill the guest and leave behind diagnostics of what
> happened; for someone debugging the crash, it's going to be less useful
> to know that page X was wrongly accessed (which is what the guest would
> see), and more useful to know that it was the kernel's vhost-... driver
> that accessed it.

I is best to let the guest #VC on the page when this happens. If it
happened because of a guest bug all necessary debugging data is in the
guest and only the guest owner can obtain it.

Then the guest owner can do a kdump on this unexpected #VC and collect
the data to debug the issue. With just killing the guest from the host
side this data would be lost.

Regards,

Joerg