Hello Steve,
On Tue, Aug 17, 2021 at 03:50:22PM -0700, Steve Rutherford wrote:
> On Tue, Jun 29, 2021 at 8:14 AM Ashish Kalra <Ashish.Kalra@xxxxxxx> wrote:
> >
> > From: Ashish Kalra <ashish.kalra@xxxxxxx>
> >
> > Reset the host's shared pages list related to kernel
> > specific page encryption status settings before we load a
> > new kernel by kexec. We cannot reset the complete
> > shared pages list here as we need to retain the
> > UEFI/OVMF firmware specific settings.
> >
> > The host's shared pages list is maintained for the
> > guest to keep track of all unencrypted guest memory regions,
> > therefore we need to explicitly mark all shared pages as
> > encrypted again before rebooting into the new guest kernel.
> >
> > Signed-off-by: Ashish Kalra <ashish.kalra@xxxxxxx>
> > ---
> > arch/x86/kernel/kvm.c | 25 +++++++++++++++++++++++++
> > 1 file changed, 25 insertions(+)
> >
> > diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
> > index a014c9bb5066..a55712ee58a1 100644
> > --- a/arch/x86/kernel/kvm.c
> > +++ b/arch/x86/kernel/kvm.c
> > @@ -869,10 +869,35 @@ static void __init kvm_init_platform(void)
> > if (sev_active() &&
> > kvm_para_has_feature(KVM_FEATURE_MIGRATION_CONTROL)) {
> > unsigned long nr_pages;
> > + int i;
> >
> > pv_ops.mmu.notify_page_enc_status_changed =
> > kvm_sev_hc_page_enc_status;
> >
> > + /*
> > + * Reset the host's shared pages list related to kernel
> > + * specific page encryption status settings before we load a
> > + * new kernel by kexec. Reset the page encryption status
> > + * during early boot intead of just before kexec to avoid SMP
> > + * races during kvm_pv_guest_cpu_reboot().
> > + * NOTE: We cannot reset the complete shared pages list
> > + * here as we need to retain the UEFI/OVMF firmware
> > + * specific settings.
> > + */
> > +
> > + for (i = 0; i < e820_table->nr_entries; i++) {
> > + struct e820_entry *entry = &e820_table->entries[i];
> > +
> > + if (entry->type != E820_TYPE_RAM)
> > + continue;
> > +
> > + nr_pages = DIV_ROUND_UP(entry->size, PAGE_SIZE);
> > +
> > + kvm_hypercall3(KVM_HC_MAP_GPA_RANGE, entry->addr,
> > + nr_pages,
> > + KVM_MAP_GPA_RANGE_ENCRYPTED | KVM_MAP_GPA_RANGE_PAGE_SZ_4K);
> > + }
> > +
> > /*
> > * Ensure that _bss_decrypted section is marked as decrypted in the
> > * shared pages list.
> > --
> > 2.17.1
> >
> I believe this entire series has been reviewed. Is there any appetite
> to queue these for 915?
> They may need to be resent, since I'm not sure there is a single patch
> series that contains all the patches.
>
I believe that there are couple or more patches still pending an ACK.
Patch#1 of this series which basically inverts the KVM hypercall from
VMCALL to VMMCALL probably needs an ack from either Sean or
Paolo.
While Patch #4 was ack'ed by Boris, it still has a dependency on Patch
#1.
Patch #5 & #6 need to be ack'ed by Boris, again have dependency on Patch
#1.
I am more than happy to send this guest kernel and guest API patch-set
for live migration again.
Please note that this guest kernel and guest API patch-set which is
essentially guest hypercall invocations are needed for both in-guest
migration and PSP based migration as they are used for tracking guest
page(s) encryption status.
Thanks,
Ashish
