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Re: [Qemu-devel] [PATCH v2 4/9] migration: Switch to using announce time
From: |
Daniel P . Berrangé |
Subject: |
Re: [Qemu-devel] [PATCH v2 4/9] migration: Switch to using announce timer |
Date: |
Wed, 30 Jan 2019 10:47:17 +0000 |
User-agent: |
Mutt/1.10.1 (2018-07-13) |
On Wed, Jan 30, 2019 at 10:32:31AM +0000, Dr. David Alan Gilbert (git) wrote:
> From: "Dr. David Alan Gilbert" <address@hidden>
>
> Switch the announcements to using the new announce timer.
> Move the code that does it to announce.c rather than savevm
> because it really has nothing to do with the actual migration.
>
> Migration starts the announce from bh's and so they're all
> in the main thread/bql, and so there's never any racing with
> the timers themselves.
>
> Signed-off-by: Dr. David Alan Gilbert <address@hidden>
> ---
> include/migration/misc.h | 10 ------
> include/net/announce.h | 2 ++
> include/sysemu/sysemu.h | 2 --
> migration/migration.c | 2 +-
> migration/migration.h | 4 +++
> migration/savevm.c | 72 ++--------------------------------------
> migration/trace-events | 1 -
> net/announce.c | 67 +++++++++++++++++++++++++++++++++++++
> net/trace-events | 4 +++
> 9 files changed, 81 insertions(+), 83 deletions(-)
> +#ifndef ETH_P_RARP
> +#define ETH_P_RARP 0x8035
> +#endif
> +#define ARP_HTYPE_ETH 0x0001
> +#define ARP_PTYPE_IP 0x0800
> +#define ARP_OP_REQUEST_REV 0x3
> +
> +static int announce_self_create(uint8_t *buf,
> + uint8_t *mac_addr)
> +{
> + /* Ethernet header. */
> + memset(buf, 0xff, 6); /* destination MAC addr */
> + memcpy(buf + 6, mac_addr, 6); /* source MAC addr */
> + *(uint16_t *)(buf + 12) = htons(ETH_P_RARP); /* ethertype */
> +
> + /* RARP header. */
> + *(uint16_t *)(buf + 14) = htons(ARP_HTYPE_ETH); /* hardware addr space */
> + *(uint16_t *)(buf + 16) = htons(ARP_PTYPE_IP); /* protocol addr space */
> + *(buf + 18) = 6; /* hardware addr length (ethernet) */
> + *(buf + 19) = 4; /* protocol addr length (IPv4) */
> + *(uint16_t *)(buf + 20) = htons(ARP_OP_REQUEST_REV); /* opcode */
> + memcpy(buf + 22, mac_addr, 6); /* source hw addr */
> + memset(buf + 28, 0x00, 4); /* source protocol addr */
> + memcpy(buf + 32, mac_addr, 6); /* target hw addr */
> + memset(buf + 38, 0x00, 4); /* target protocol addr */
> +
> + /* Padding to get up to 60 bytes (ethernet min packet size, minus FCS).
> */
> + memset(buf + 42, 0x00, 18);
> +
> + return 60; /* len (FCS will be added by hardware) */
> +}
I think I would suggest defining a packed struct for the ethernet
packet we're sending, so we can just reference named fields instead
of magic offsets. Then I realized this patch is just moving some
pre-existing code, so it is probably better to leave it as it is
in this patch, as mixing code movement with refactoring is bad
practice. If anyone fancies doing a latter patch to use a struct
though, it might be nice.
Regards,
Daniel
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[Qemu-devel] [PATCH v2 3/9] virtio-net: Switch to using announce timer, Dr. David Alan Gilbert (git), 2019/01/30
[Qemu-devel] [PATCH v2 4/9] migration: Switch to using announce timer, Dr. David Alan Gilbert (git), 2019/01/30
- Re: [Qemu-devel] [PATCH v2 4/9] migration: Switch to using announce timer,
Daniel P . Berrangé <=
[Qemu-devel] [PATCH v2 5/9] net: Add a network device specific self-announcement ability, Dr. David Alan Gilbert (git), 2019/01/30
[Qemu-devel] [PATCH v2 6/9] virtio-net: Allow qemu_announce_self to trigger virtio announcements, Dr. David Alan Gilbert (git), 2019/01/30
[Qemu-devel] [PATCH v2 7/9] qmp: Add announce-self command, Dr. David Alan Gilbert (git), 2019/01/30
[Qemu-devel] [PATCH v2 8/9] hmp: Add hmp_announce_self, Dr. David Alan Gilbert (git), 2019/01/30
[Qemu-devel] [PATCH v2 9/9] tests: Add a test for qemu self announcements, Dr. David Alan Gilbert (git), 2019/01/30