Merge branch 'kvm-5.16-fixes' into kvm-master

[sfrench/cifs-2.6.git] / arch / x86 / kernel / kvm.c

diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index c97859170286cf801171b4a529183d6af2ff6ab5..59abbdad7729c859fea3e1465413119696439943 100644 (file)
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -27,6 +27,8 @@
 #include <linux/nmi.h>
 #include <linux/swait.h>
 #include <linux/syscore_ops.h>
+#include <linux/cc_platform.h>
+#include <linux/efi.h>
 #include <asm/timer.h>
 #include <asm/cpu.h>
 #include <asm/traps.h>
@@ -40,6 +42,7 @@
 #include <asm/ptrace.h>
 #include <asm/reboot.h>
 #include <asm/svm.h>
+#include <asm/e820/api.h>
 
 DEFINE_STATIC_KEY_FALSE(kvm_async_pf_enabled);
 
@@ -418,7 +421,7 @@ static void __init sev_map_percpu_data(void)
 {
        int cpu;
 
-       if (!sev_active())
+       if (!cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
                return;
 
        for_each_possible_cpu(cpu) {
@@ -433,6 +436,8 @@ static void kvm_guest_cpu_offline(bool shutdown)
        kvm_disable_steal_time();
        if (kvm_para_has_feature(KVM_FEATURE_PV_EOI))
                wrmsrl(MSR_KVM_PV_EOI_EN, 0);
+       if (kvm_para_has_feature(KVM_FEATURE_MIGRATION_CONTROL))
+               wrmsrl(MSR_KVM_MIGRATION_CONTROL, 0);
        kvm_pv_disable_apf();
        if (!shutdown)
                apf_task_wake_all();
@@ -547,6 +552,55 @@ static void kvm_send_ipi_mask_allbutself(const struct cpumask *mask, int vector)
        __send_ipi_mask(local_mask, vector);
 }
 
+static int __init setup_efi_kvm_sev_migration(void)
+{
+       efi_char16_t efi_sev_live_migration_enabled[] = L"SevLiveMigrationEnabled";
+       efi_guid_t efi_variable_guid = AMD_SEV_MEM_ENCRYPT_GUID;
+       efi_status_t status;
+       unsigned long size;
+       bool enabled;
+
+       if (!cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT) ||
+           !kvm_para_has_feature(KVM_FEATURE_MIGRATION_CONTROL))
+               return 0;
+
+       if (!efi_enabled(EFI_BOOT))
+               return 0;
+
+       if (!efi_enabled(EFI_RUNTIME_SERVICES)) {
+               pr_info("%s : EFI runtime services are not enabled\n", __func__);
+               return 0;
+       }
+
+       size = sizeof(enabled);
+
+       /* Get variable contents into buffer */
+       status = efi.get_variable(efi_sev_live_migration_enabled,
+                                 &efi_variable_guid, NULL, &size, &enabled);
+
+       if (status == EFI_NOT_FOUND) {
+               pr_info("%s : EFI live migration variable not found\n", __func__);
+               return 0;
+       }
+
+       if (status != EFI_SUCCESS) {
+               pr_info("%s : EFI variable retrieval failed\n", __func__);
+               return 0;
+       }
+
+       if (enabled == 0) {
+               pr_info("%s: live migration disabled in EFI\n", __func__);
+               return 0;
+       }
+
+       pr_info("%s : live migration enabled in EFI\n", __func__);
+       wrmsrl(MSR_KVM_MIGRATION_CONTROL, KVM_MIGRATION_READY);
+
+       return 1;
+}
+
+late_initcall(setup_efi_kvm_sev_migration);
+
 /*
  * Set the IPI entry points
  */
@@ -805,8 +859,62 @@ static bool __init kvm_msi_ext_dest_id(void)
        return kvm_para_has_feature(KVM_FEATURE_MSI_EXT_DEST_ID);
 }
 
+static void kvm_sev_hc_page_enc_status(unsigned long pfn, int npages, bool enc)
+{
+       kvm_sev_hypercall3(KVM_HC_MAP_GPA_RANGE, pfn << PAGE_SHIFT, npages,
+                          KVM_MAP_GPA_RANGE_ENC_STAT(enc) | KVM_MAP_GPA_RANGE_PAGE_SZ_4K);
+}
+
 static void __init kvm_init_platform(void)
 {
+       if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT) &&
+           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.
+                */
+               nr_pages = DIV_ROUND_UP(__end_bss_decrypted - __start_bss_decrypted,
+                                       PAGE_SIZE);
+               early_set_mem_enc_dec_hypercall((unsigned long)__start_bss_decrypted,
+                                               nr_pages, 0);
+
+               /*
+                * If not booted using EFI, enable Live migration support.
+                */
+               if (!efi_enabled(EFI_BOOT))
+                       wrmsrl(MSR_KVM_MIGRATION_CONTROL,
+                              KVM_MIGRATION_READY);
+       }
        kvmclock_init();
        x86_platform.apic_post_init = kvm_apic_init;
 }