From: David Gibson <david@gibson.dropbear.id.au>
To: Daniel Henrique Barboza <danielhb413@gmail.com>
Cc: qemu-ppc@nongnu.org, qemu-devel@nongnu.org, groug@kaod.org
Subject: Re: [PATCH 1/1] spapr_drc.c: handle hotunplug errors in drc_unisolate_logical()
Date: Mon, 19 Apr 2021 14:08:46 +1000 [thread overview]
Message-ID: <YH0CToT0lEcvmtxy@yekko.fritz.box> (raw)
In-Reply-To: <20210416210941.381119-2-danielhb413@gmail.com>
[-- Attachment #1: Type: text/plain, Size: 2992 bytes --]
On Fri, Apr 16, 2021 at 06:09:41PM -0300, Daniel Henrique Barboza wrote:
> The Linux kernel will call set-indicator to move a DRC to 'unisolate' in
> the case a device removal fails. Setting a DRC that is already
Only issue I have with this patch is that this isn't quite accurate
yet. Can you reword this to include some of the rationale from the
cover letters about how a previous no-op is a safe choice to allow
guest->hv error signalling and that we expect the Linux kernel to use
it at some point.
> unisolated or configured to 'unisolate' is a no-op for the current
> hypervisors that supports pSeries guests, namely QEMU and phyp, and is
> being used to signal hotunplug errors if the hypervisor has the code for
> it.
>
> This patch changes drc_unisolate_logical() to implement in the pSeries
> machine. For CPUs it's a simple matter of setting drc->unplug_requested
> to 'false', while for LMBs the process is similar to the rollback that
> is done in rtas_ibm_configure_connector(). Although at this moment the
> Linux kernel is only reporting CPU removal errors, let's get the code
> ready to handle LMBs as well.
>
> Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Otherwise,
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
> ---
> hw/ppc/spapr_drc.c | 23 +++++++++++++++++++++++
> 1 file changed, 23 insertions(+)
>
> diff --git a/hw/ppc/spapr_drc.c b/hw/ppc/spapr_drc.c
> index 9e16505fa1..6918e0c9d1 100644
> --- a/hw/ppc/spapr_drc.c
> +++ b/hw/ppc/spapr_drc.c
> @@ -151,9 +151,32 @@ static uint32_t drc_isolate_logical(SpaprDrc *drc)
>
> static uint32_t drc_unisolate_logical(SpaprDrc *drc)
> {
> + SpaprMachineState *spapr = NULL;
> +
> switch (drc->state) {
> case SPAPR_DRC_STATE_LOGICAL_UNISOLATE:
> case SPAPR_DRC_STATE_LOGICAL_CONFIGURED:
> + /*
> + * Unisolating a logical DRC that was marked for unplug
> + * means that the kernel is refusing the removal.
> + */
> + if (drc->unplug_requested && drc->dev) {
> + if (spapr_drc_type(drc) == SPAPR_DR_CONNECTOR_TYPE_LMB) {
> + spapr = SPAPR_MACHINE(qdev_get_machine());
> +
> + spapr_memory_unplug_rollback(spapr, drc->dev);
> + }
> +
> + drc->unplug_requested = false;
> + error_report("Device hotunplug rejected by the guest "
> + "for device %s", drc->dev->id);
> +
> + /*
> + * TODO: send a QAPI DEVICE_UNPLUG_ERROR event when
> + * it is implemented.
> + */
> + }
> +
> return RTAS_OUT_SUCCESS; /* Nothing to do */
> case SPAPR_DRC_STATE_LOGICAL_AVAILABLE:
> break; /* see below */
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]
prev parent reply other threads:[~2021-04-19 4:10 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-16 21:09 [PATCH 0/1] pSeries: handle hotunplug errors in drc_unisolate_logical() Daniel Henrique Barboza
2021-04-16 21:09 ` [PATCH 1/1] spapr_drc.c: " Daniel Henrique Barboza
2021-04-19 4:08 ` David Gibson [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=YH0CToT0lEcvmtxy@yekko.fritz.box \
--to=david@gibson.dropbear.id.au \
--cc=danielhb413@gmail.com \
--cc=groug@kaod.org \
--cc=qemu-devel@nongnu.org \
--cc=qemu-ppc@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).