Re: [PATCH v8 16/18] KVM: x86: Mark _bss_decrypted section variables as decrypted in page encryption bitmap.

[Steve Rutherford]

On Tue, May 5, 2020 at 2:20 PM Ashish Kalra <Ashish.Kalra@xxxxxxx> wrote:
>
> From: Ashish Kalra <ashish.kalra@xxxxxxx>
>
> Ensure that _bss_decrypted section variables such as hv_clock_boot and
> wall_clock are marked as decrypted in the page encryption bitmap if
> sev liv migration is supported.
>
> Signed-off-by: Ashish Kalra <ashish.kalra@xxxxxxx>
> ---
>  arch/x86/kernel/kvmclock.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
>
> diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
> index 34b18f6eeb2c..65777bf1218d 100644
> --- a/arch/x86/kernel/kvmclock.c
> +++ b/arch/x86/kernel/kvmclock.c
> @@ -334,6 +334,18 @@ void __init kvmclock_init(void)
>         pr_info("kvm-clock: Using msrs %x and %x",
>                 msr_kvm_system_time, msr_kvm_wall_clock);
>
> +       if (sev_live_migration_enabled()) {
> +               unsigned long nr_pages;
> +               /*
> +                * sizeof(hv_clock_boot) is already PAGE_SIZE aligned
> +                */
> +               early_set_mem_enc_dec_hypercall((unsigned long)hv_clock_boot,
> +                                               1, 0);
> +               nr_pages = DIV_ROUND_UP(sizeof(wall_clock), PAGE_SIZE);
> +               early_set_mem_enc_dec_hypercall((unsigned long)&wall_clock,
> +                                               nr_pages, 0);
> +       }
> +
>         this_cpu_write(hv_clock_per_cpu, &hv_clock_boot[0]);
>         kvm_register_clock("primary cpu clock");
>         pvclock_set_pvti_cpu0_va(hv_clock_boot);
> --
> 2.17.1
>

Reviewed-by: Steve Rutherford <srutherford@xxxxxxxxxx>