[PATCH v7 08/13] confidential guest support: Move SEV initialization into arch specific code

David Gibson
2021-01-14T01:53:47Z

While we've abstracted some (potential) differences between mechanisms for
securing guest memory, the initialization is still specific to SEV. Given
that, move it into x86's kvm_arch_init() code, rather than the generic
kvm_init() code.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
accel/kvm/kvm-all.c | 14 --------------
accel/kvm/sev-stub.c | 4 ++--
target/i386/kvm/kvm.c | 12 ++++++++++++
target/i386/sev.c | 7 ++++++-
4 files changed, 20 insertions(+), 17 deletions(-)

diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index c5b0750fd0..adf27c1864 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -2177,20 +2177,6 @@ static int kvm_init(MachineState *ms)

kvm_state = s;

- /*
- * if memory encryption object is specified then initialize the memory
- * encryption context.
- */
- if (ms->cgs) {
- Error *local_err = NULL;
- /* FIXME handle mechanisms other than SEV */
- ret = sev_kvm_init(ms->cgs, &local_err);
- if (ret < 0) {
- error_report_err(local_err);
- goto err;
- }
- }
-
ret = kvm_arch_init(ms, s);
if (ret < 0) {
goto err;
diff --git a/accel/kvm/sev-stub.c b/accel/kvm/sev-stub.c
index 512e205f7f..9587d1b2a3 100644
--- a/accel/kvm/sev-stub.c
+++ b/accel/kvm/sev-stub.c
@@ -17,6 +17,6 @@

int sev_kvm_init(ConfidentialGuestSupport *cgs, Error **errp)
{
- /* SEV can't be selected if it's not compiled */
- g_assert_not_reached();
+ /* If we get here, cgs must be some non-SEV thing */
+ return 0;
}
diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index 6dc1ee052d..e8b9dc48a2 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -42,6 +42,7 @@
#include "hw/i386/intel_iommu.h"
#include "hw/i386/x86-iommu.h"
#include "hw/i386/e820_memory_layout.h"
+#include "sysemu/sev.h"

#include "hw/pci/pci.h"
#include "hw/pci/msi.h"
@@ -2135,6 +2136,17 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
uint64_t shadow_mem;
int ret;
struct utsname utsname;
+ Error *local_err = NULL;
+
+ /*
+ * if memory encryption object is specified then initialize the
+ * memory encryption context (no-op otherwise)
+ */
+ ret = sev_kvm_init(ms->cgs, &local_err);
+ if (ret < 0) {
+ error_report_err(local_err);
+ return ret;
+ }

if (!kvm_check_extension(s, KVM_CAP_IRQ_ROUTING)) {
error_report("kvm: KVM_CAP_IRQ_ROUTING not supported by KVM");
diff --git a/target/i386/sev.c b/target/i386/sev.c
index 3d94635397..aa79cacabe 100644
--- a/target/i386/sev.c
+++ b/target/i386/sev.c
@@ -664,13 +664,18 @@ sev_vm_state_change(void *opaque, int running, RunState state)

int sev_kvm_init(ConfidentialGuestSupport *cgs, Error **errp)
{
- SevGuestState *sev = SEV_GUEST(cgs);
+ SevGuestState *sev
+ = (SevGuestState *)object_dynamic_cast(OBJECT(cgs), TYPE_SEV_GUEST);
char *devname;
int ret, fw_error;
uint32_t ebx;
uint32_t host_cbitpos;
struct sev_user_data_status status = {};

+ if (!sev) {
+ return 0;
+ }
+
ret = ram_block_discard_disable(true);
if (ret) {
error_report("%s: cannot disable RAM discard", __func__);
--
2.29.2