From: Paolo Bonzini <pbonzini@redhat.com>
To: huangy81@chinatelecom.cn, qemu-devel <qemu-devel@nongnu.org>
Cc: peterx <peterx@redhat.com>
Subject: Re: [PATCH] kvm: mirror "-machine dirty_gfn_count" to the accelerator property
Date: Fri, 8 Jan 2021 21:41:21 +0100 [thread overview]
Message-ID: <3aa73987-40e8-3619-0723-9f17f73850bd@redhat.com> (raw)
In-Reply-To: <1610132911-33839-1-git-send-email-huangy81@chinatelecom.cn>
On 08/01/21 20:08, huangy81@chinatelecom.cn wrote:
> QEMU enable the dirty ring feature by specifing the "-accel" sub-parameter.
> https://lore.kernel.org/qemu-devel/20210108165050.406906-10-peterx@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 <huangy81@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 */ }
> }
>
prev parent reply other threads:[~2021-01-08 20:42 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-08 19:08 [PATCH] kvm: mirror "-machine dirty_gfn_count" to the accelerator property huangy81
2021-01-08 20:41 ` Paolo Bonzini [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=3aa73987-40e8-3619-0723-9f17f73850bd@redhat.com \
--to=pbonzini@redhat.com \
--cc=huangy81@chinatelecom.cn \
--cc=peterx@redhat.com \
--cc=qemu-devel@nongnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).