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authorAshish Kalra2021-08-24 11:07:45 +0000
committerPaolo Bonzini2021-11-11 07:37:44 -0500
commit73f1b4fece216c2e72be74c4d0d0f71a0b944bec (patch)
tree04887282305fc5c0f9d9a4d7507d22d5d81c46cd /arch/x86
parentf4495615d76cfe5a633b0886b5c30310ed94c357 (diff)
x86/kvm: Add kexec support for SEV Live Migration.
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@amd.com> Reviewed-by: Steve Rutherford <srutherford@google.com> Message-Id: <3e051424ab839ea470f88333273d7a185006754f.1629726117.git.ashish.kalra@amd.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kernel/kvm.c25
1 files changed, 25 insertions, 0 deletions
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index a672a2ef65b3..3910419fae6c 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -869,11 +869,36 @@ 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_sev_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.
*/