On 08/01/21 20:08, huang...@chinatelecom.cn wrote:
QEMU enable the dirty ring feature by specifing the "-accel" sub-parameter.
https://lore.kernel.org/qemu-devel/20210108165050.406906-10-pet...@redhat.com/
Libvirt use "-machine accel=kvm" option to specify the accelerator by default,
which is incompatible with above option.
This patch introduce the "dirty_gfn_count" sub-parameter of the "-machine"
in the way that the commit "23b089" has done. So that Libvirt can enable this
feature by adding "-machine dirty_gfn_count=xxx" to the QEMU command line.
Signed-off-by: Hyman <huang...@chinatelecom.cn>
Libvirt should switch to "-accel kvm" instead. The "-machine" options
for accelerators are legacy and now there is a better mechanism. There
will never be a version of QEMU that supports dirty ring and doesn't
support "-accel kvm", so it's easy for Libvirt to detect when to use
"-accel".
Paolo
---
softmmu/vl.c | 3 ++-
util/qemu-config.c | 4 ++++
2 files changed, 6 insertions(+), 1 deletion(-)
diff --git a/softmmu/vl.c b/softmmu/vl.c
index 7ddf405..d8e3dec 100644
--- a/softmmu/vl.c
+++ b/softmmu/vl.c
@@ -1666,7 +1666,8 @@ static int machine_set_property(void *opaque,
object_register_sugar_prop(ACCEL_CLASS_NAME("xen"), qom_name, value);
return 0;
}
- if (g_str_equal(qom_name, "kvm-shadow-mem")) {
+ if (g_str_equal(qom_name, "kvm-shadow-mem") ||
+ g_str_equal(qom_name, "dirty-gfn-count")) {
object_register_sugar_prop(ACCEL_CLASS_NAME("kvm"), qom_name, value);
return 0;
}
diff --git a/util/qemu-config.c b/util/qemu-config.c
index e2a700b..70f1b50 100644
--- a/util/qemu-config.c
+++ b/util/qemu-config.c
@@ -234,6 +234,10 @@ static QemuOptsList machine_opts = {
.help = "Up to 8 chars in set of [A-Za-z0-9. ](lower case chars"
" converted to upper case) to pass to machine"
" loader, boot manager, and guest kernel",
+ },{
+ .name = "dirty_gfn_count",
+ .type = QEMU_OPT_NUMBER,
+ .help = "KVM dirty ring GFN count",
},
{ /* End of list */ }
}
