On 2/8/22 16:35, Nico Boehr wrote:
On Tue, 2022-02-08 at 14:27 +0100, Pierre Morel wrote:
We need in several tests to check if the VM we are running in
is KVM.
Let's add the test.
To check the VM type we use the STSI 3.2.2 instruction, let's
define it's response structure in a central header.
Signed-off-by: Pierre Morel <pmorel@xxxxxxxxxxxxx>
---
lib/s390x/stsi.h | 32 +++++++++++++++++++++++++++
lib/s390x/vm.c | 56
++++++++++++++++++++++++++++++++++++++++++++++--
lib/s390x/vm.h | 3 +++
s390x/stsi.c | 23 ++------------------
4 files changed, 91 insertions(+), 23 deletions(-)
create mode 100644 lib/s390x/stsi.h
diff --git a/lib/s390x/stsi.h b/lib/s390x/stsi.h
new file mode 100644
index 00000000..9b40664f
--- /dev/null
+++ b/lib/s390x/stsi.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
This was taken from stsi.c which is GPL 2 only, so this probably should
be as well.
diff --git a/lib/s390x/vm.c b/lib/s390x/vm.c
index a5b92863..38886b76 100644
--- a/lib/s390x/vm.c
+++ b/lib/s390x/vm.c
@@ -12,6 +12,7 @@
#include <alloc_page.h>
#include <asm/arch_def.h>
#include "vm.h"
+#include "stsi.h"
/**
* Detect whether we are running with TCG (instead of KVM)
@@ -26,9 +27,13 @@ bool vm_is_tcg(void)
if (initialized)
return is_tcg;
- buf = alloc_page();
- if (!buf)
+ if (!vm_is_vm()) {
+ initialized = true;
return false;
diff --git a/lib/s390x/vm.c b/lib/s390x/vm.c
index a5b92863..38886b76 100644
--- a/lib/s390x/vm.c
+++ b/lib/s390x/vm.c
@@ -12,6 +12,7 @@
#include <alloc_page.h>
#include <asm/arch_def.h>
#include "vm.h"
+#include "stsi.h"
/**
* Detect whether we are running with TCG (instead of KVM)
@@ -26,9 +27,13 @@ bool vm_is_tcg(void)
if (initialized)
return is_tcg;
- buf = alloc_page();
- if (!buf)
+ if (!vm_is_vm()) {
+ initialized = true;
return false;
I would personally prefer return is_tcg here to make it obvious we're
relying on the previous initalization to false for subsequent calls.
OK
+ }
+
+ buf = alloc_page();
+ assert(buf);
if (stsi(buf, 1, 1, 1))
goto out;
@@ -43,3 +48,50 @@ out:
free_page(buf);
return is_tcg;
}
+
+/**
+ * Detect whether we are running with KVM
+ */
+
No newline here.
ok
+bool vm_is_kvm(void)
+{
+ /* EBCDIC for "KVM/" */
+ const uint8_t kvm_ebcdic[] = { 0xd2, 0xe5, 0xd4, 0x61 };
+ static bool initialized;
+ static bool is_kvm;
Might make sense to initizalize these to false to make it consistent
with vm_is_tcg().
OK
--
Pierre Morel
IBM Lab Boeblingen
