[src/trunk]: src/lib/libnvmm Implement nvmm_vcpu::stop, a race-free exit from...

[reinoud <reinoud%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/f2274df6d368
branches:  trunk
changeset: 1020281:f2274df6d368
user:      reinoud <reinoud%NetBSD.org@localhost>
date:      Tue Apr 06 08:40:17 2021 +0000

description:
Implement nvmm_vcpu::stop, a race-free exit from nvmm_vcpu_run() without
signals. This introduces a new kernel and userland NVMM version indicating
this support.

Patch by Kamil Rytarowski <kamil%netbsd.org@localhost> and committed on his request.

This is the missing libnvmm part I forgot to include in the origional commit.

diffstat:

 lib/libnvmm/libnvmm.c |  12 +++++++++++-
 lib/libnvmm/nvmm.h    |  12 ++++++++++--
 2 files changed, 21 insertions(+), 3 deletions(-)

diffs (68 lines):

diff -r 10b83828a1bc -r f2274df6d368 lib/libnvmm/libnvmm.c
--- a/lib/libnvmm/libnvmm.c     Tue Apr 06 08:19:15 2021 +0000
+++ b/lib/libnvmm/libnvmm.c     Tue Apr 06 08:40:17 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: libnvmm.c,v 1.19 2020/09/05 07:22:25 maxv Exp $        */
+/*     $NetBSD: libnvmm.c,v 1.20 2021/04/06 08:40:17 reinoud Exp $     */
 
 /*
  * Copyright (c) 2018-2020 Maxime Villard, m00nbsd.net
@@ -310,6 +310,7 @@
        vcpu->cpuid = cpuid;
        vcpu->state = &comm->state;
        vcpu->event = &comm->event;
+       vcpu->stop = &comm->stop;
        vcpu->exit = malloc(sizeof(*vcpu->exit));
 
        return 0;
@@ -561,3 +562,12 @@
 
        return 0;
 }
+
+int
+nvmm_vcpu_stop(struct nvmm_vcpu *vcpu)
+{
+
+       *vcpu->stop = 1;
+
+       return 0;
+}
diff -r 10b83828a1bc -r f2274df6d368 lib/libnvmm/nvmm.h
--- a/lib/libnvmm/nvmm.h        Tue Apr 06 08:19:15 2021 +0000
+++ b/lib/libnvmm/nvmm.h        Tue Apr 06 08:40:17 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: nvmm.h,v 1.18 2020/09/05 07:22:25 maxv Exp $   */
+/*     $NetBSD: nvmm.h,v 1.19 2021/04/06 08:40:17 reinoud Exp $        */
 
 /*
  * Copyright (c) 2018-2020 Maxime Villard, m00nbsd.net
@@ -37,7 +37,12 @@
 #include <dev/nvmm/nvmm.h>
 #include <dev/nvmm/nvmm_ioctl.h>
 
-#define NVMM_USER_VERSION      1
+#define NVMM_USER_VERSION      2
+
+/*
+ * Version 1 - Initial release in NetBSD 9.0.
+ * Version 2 - Added nvmm_vcpu::stop.
+ */
 
 struct nvmm_io;
 struct nvmm_mem;
@@ -59,6 +64,7 @@
        struct nvmm_vcpu_state *state;
        struct nvmm_vcpu_event *event;
        struct nvmm_vcpu_exit *exit;
+       volatile int *stop;
 };
 
 struct nvmm_io {
@@ -123,4 +129,6 @@
 
 int nvmm_vcpu_dump(struct nvmm_machine *, struct nvmm_vcpu *);
 
+int nvmm_vcpu_stop(struct nvmm_vcpu *);
+
 #endif /* _LIBNVMM_H_ */