Re: [PATCH v3 27/49] i386/sev: Set ms->require_guest_memfd for SNP

[Paolo Bonzini]

On 3/20/24 09:39, Michael Roth wrote:
> SNP requires guest_memfd for private guest memory, so enable it so that
> the appropriate guest_memfd backend will be available for normal RAM
> regions.
>
> Signed-off-by: Michael Roth <michael.roth@amd.com>
> ---
>   target/i386/sev.c | 5 +++++
>   1 file changed, 5 insertions(+)
>
> diff --git a/target/i386/sev.c b/target/i386/sev.c
> index e4deb7b41e..b06c796aae 100644
> --- a/target/i386/sev.c
> +++ b/target/i386/sev.c
> @@ -880,6 +880,7 @@ out:
>   static int sev_kvm_init(ConfidentialGuestSupport *cgs, Error **errp)
>   {
>       SevCommonState *sev_common = SEV_COMMON(cgs);
> +    MachineState *ms = MACHINE(qdev_get_machine());
>       char *devname;
>       int ret, fw_error, cmd;
>       uint32_t ebx;
> @@ -1000,6 +1001,10 @@ static int sev_kvm_init(ConfidentialGuestSupport *cgs, 
> Error **errp)
>           qemu_add_machine_init_done_notifier(&sev_machine_done_notify);
>       }
>   
> +    if (sev_snp_enabled()) {
> +        ms->require_guest_memfd = true;
> +    }

Likewise, this and the following patch should be done in the 
sev-snp-guest's override of kvm_init.

Paolo

>       qemu_add_vm_change_state_handler(sev_vm_state_change, sev_common);
>   
>       cgs->ready = true;